civil engineering works...issue no. 4: january 2004 (i) general materials & workmanship...

GENERAL

MATERIALS AND WORKMANSHIP

SPECIFICATION

VOLUME 1 OF 4 (SECTIONS 1 – 14)

CIVIL ENGINEERING WORKS

ISSUE NO. 4 JANUARY

2004

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Issue No. 4: January 2004 - i - General Materials & Workmanship Specification

GENERAL MATERIALS AND WORKMANSHIP SPECIFICATION

TABLE OF CONTENTS

VOLUME 1 CIVIL ENGINEERING WORKS

SECTION 1 ABBREVIATIONS, STANDARDS AND GENERAL SECTION 2 TEMPORARY WORKS SECTION 3 SITE CLEARANCE AND DEMOLITION SECTION 4 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS SECTION 5 FENCING SECTION 6 DRAINAGE WORKS SECTION 7 EARTHWORKS SECTION 8 GEOTECHNICAL WORKS SECTION 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS

MATERIALS SECTION 10 CONCRETE CARRIAGEWAYS SECTION 11 MISCELLANEOUS ROADWORKS SECTION 12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL

INSTALLATIONS SECTION 14 WATER SUPPLY PIPEWORKS VOLUME 2 STRUCTURAL ENGINEERING WORKS

SECTION 15 NOT USED SECTION 16 ABBREVIATIONS, STANDARDS AND GENERAL –

STRUCTURES SECTION 17 PILING WORKS SECTION 18 FORMWORK AND FINISHES TO CONCRETE SECTION 19 STEEL REINFORCMENT SECTION 20 CONCRETE AND JOINTS IN CONCRETE SECTION 21 PRESTRESSING SECTION 22 STEELWORK SECTION 23 BRIDGEWORKS SECTION 24 WATER RETAINING STRUCTURES VOLUME 3 ARCHITECTURAL WORKS

SECTION 25 NOT USED SECTION 26 MASONRY AND BLOCKWORK SECTION 27 WATERPROOFING AND TANKING SECTION 28 ROOFING AND WALL CLADDING SECTION 29 CURTAIN WALLING SECTION 30 INTERNAL CLADDING SYSTEMS SECTION 31 CARPENTRY AND JOINERY SECTION 32 GLAZING, GLAZED SCREENS, BALUSTRADES AND

HANDRAILS SECTION 33 LININGS, SHEATHINGS, DRYWALL PARTITIONS AND

TOILET CUBICLES SECTION 34 SUSPENDED CEILINGS

Issue No. 4: January 2004 - ii - General Materials & Workmanship Specification


TABLE OF CONTENTS (CONT’D)

VOLUME 3 ARCHITECTURAL WORKS

SECTION 35 ARCHITECTURAL METALWORK (INCLUDING METAL DOORS AND SHUTTERS)

SECTION 36 IRONMONGERY SECTION 37 HARD FLOOR FINISHES SECTION 38 FLEXIBLE FLOOR FINISHES SECTION 39 WALL FINISHES SECTION 40 PAINTING AND DECORATION SECTION 41 FIRE PROTECTION AND FIRE STOPPING SYSTEMS SECTION 42 SIGNAGE VOLUME 4 ELECTRICAL AND MECHANICAL WORKS

SECTION 43 NOT USED SECTION 44 ABBREVIATIONS, STANDARDS AND GENERAL –

ELECTRICAL AND MECHANICAL SECTION 45 ELECTRIC POWER SUPPLY SECTION 46 LOW VOLTAGE SWITCHBOARDS SECTION 47 SUB-MAINS ELECTRICAL DISTRIBUTION EQUIPMENT SECTION 48 WIRING AND CABLES SECTION 49 CABLE MANAGEMENT SYSTEMS SECTION 50 WIRING ACCESSORIES AND MISCELLANEOUS

ELECTRICAL EQUIPMENT SECTION 51 GENERAL LIGHTING SYSTEMS SECTION 52 UNINTERRUPTIBLE POWER SUPPLY SYSTEM (UPS) SECTION 53 MOTORS SECTION 54 HIGH VOLTAGE ELECTRICAL SERVICES SECTION 55 NOT USED SECTION 56 NOT USED SECTION 57 EARTHING AND BONDING SYSTEM SECTION 58 LIGHTNING PROTECTION SYSTEM SECTION 59 ELECTROMAGNETIC COMPATIBILITY SECTION 60 INSPECTION, TESTING AND COMMISSIONING

ELECTRICAL SYSTEMS SECTION 61 AIR HANDLING UNITS SECTION 62 FAN COIL UNITS SECTION 63 FANS SECTION 64 SPLIT TYPE AIR CONDITIONING UNIT SECTION 65 WINDOW TYPE AIR CONDITIONING UNIT SECTION 66 AIR COOLING COILS SECTION 67 DAMPERS AND AIR VOLUME CONTROL DEVICES SECTION 68 REGISTERS, DIFFUSERS AND GRILLES SECTION 69 AIR FILTERS SECTION 70 DUCTWORK AND FITTINGS SECTION 71 WATER HANDLING EQUIPMENT SECTION 72 PIPEWORK, FITTINGS AND VALVES SECTION 73 THERMAL INSULATION

Issue No. 4: January 2004 - iii - General Materials & Workmanship Specification


TABLE OF CONTENTS (CONT’D)

VOLUME 4 ELECTRICAL AND MECHANICAL WORKS

SECTION 74 SOUND ATTENTUATORS SECTION 75 NOISE AND VIBRATION CONTROL SECTION 76 ELECTRICAL EQUIPMENT AND INSTALLATION SECTION 77 AUTOMATIC CONTROLS SECTION 78 INSTRUMENTS SECTION 79 TESTING, INSPECTION AND COMMISSIONING SECTION 80 AUTOMATIC SPRINKLER SYSTEM SECTION 81 HYDRANT AND HOSE REEL SYSTEM SECTION 82 GASEOUS FIRE EXTINGUISHING SYSTEM (FM200) SECTION 83 FIRE ALARM AND DETECTION SYSTEM SECTION 84 PORTABLE HAND HELD EQUIPMENT SECTION 85 VISUAL FIRE ALARM SECTION 86 EXIT SIGN AND DIRECTIONAL SIGN SECTION 87 PIPEWORK, VALVES AND FITTINGS SECTION 88 PUMPS AND TANKS SECTION 89 ELECTRICAL EQUIPMENT AND INSTALLATION SECTION 90 INSPECTION, TESTING AND COMMISSIONING – FIRE

SYSTEMS SECTION 91 FOUL WATER DISPOSAL SECTION 92 STORM WATER DISPOSAL SECTION 93 WATER SUPPLY SECTION 94 HOT WATER SUPPLY SYSTEM SECTION 95 PIPEWORK, FITTINGS AND VALVES SECTION 96 TOWN GAS RETICULATION SECTION 97 PUMPS AND TANK LEVEL CONTROLS SECTION 98 ELECTRICAL EQUIPMENT AND INSTALLATION SECTION 99 INSPECTION, TESTING AND COMMISSIONING –

HYDRAULIC SERVICES SECTION 100 GENERAL BUILDING MANAGEMENT SYSTEM SECTION 101 MECHANICAL BUILDING MANAGEMENT SYSTEM SECTION 102 VOICE AND DATA CABLING SECTION 103 PUBLIC ADDRESS SYSTEM SECTION 104 ACCESS CONTROL SYSTEM SECTION 105 TRUNKED MOBILE RADIO SYSTEM SECTION 106 CLOSED CIRCUIT TELEVISION SYSTEM SECTION 107 MASTER ANTENNA TELEVISION (MATV) SECTION 108 INSPECTION, TESTING AND COMMISSIONING SYSTEM

Issue No. 4: January 2004 (i) General Materials & Workmanship Specification


VOLUME 1 – CIVIL ENGINEERING WORKS SECTION 1 ABBREVIATIONS, STANDARDS AND GENERAL 1.1 Definitions and Abbreviations 1.2 Relevant Codes and Standards SECTION 2 TEMPORARY WORKS 2.1 Introduction 2.2 Design and Performance Criteria APPENDIX A2.1 TEMPORARY WORKS DESIGN CRITERIA A2.1.1 Preamble A2.1.2 Ground Movement A2.1.3 Ground Water A2.1.4 Construction Method A2.1.5 Loads and Forces A2.1.6 Excavation A2.1.7 Design Life A2.1.8 Cofferdams and Temporary Retaining Walls A2.1.9 Temporary Decks and Pedestrian Bridges A2.1.10 Falsework A2.1.11 Formwork A2.1.12 Earthworks APPENDIX A2.2 CERTIFICATION OF THE DESIGN OF TEMPORARY WORKS APPENDIX A2.3 CERTIFICATION OF LOADING, DISMANTLING OR

REMOVAL OF TEMPORARY WORKS SECTION 3 SITE CLEARANCE AND DEMOLITION 3.1 General 3.2 Relevant Codes and Standards 3.3 Submissions 3.4 Workmanship 3.5 Inspection SECTION 4 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS 4.1 General 4.2 Definitions and Abbreviations 4.3 Relevant Codes and Standards 4.4 Materials 4.5 Submissions 4.6 Workmanship 4.7 Inspection, Testing and Commissioning APPENDIX A4.1 BRITISH STANDARDS PUBLICATIONS

Issue No. 4: January 2004 (ii) General Materials & Workmanship Specification

SECTION 5 FENCING 5.1 General 5.2 Design and Performance Criteria 5.3 Materials 5.4 Submissions 5.5 Workmanship SECTION 6 DRAINAGE WORKS 6.1 General 6.2 Glossary of Terms 6.3 Materials 6.4 Submissions 6.5 Workmanship 6.6 Inspection, Testing and Commissioning APPENDIX A6.1 CCTV INSPECTION OF PIPELINES A6.1.1 Scope A6.1.2 Equipment A6.1.3 Procedure A6.1.4 Recording of Results APPENDIX A6.2 DETERMINATION OF THE COMPACTION FRACTION

VALUE OF AGGREGATES FOR GRANULAR BED A6.2.1 Scope A6.2.2 Apparatus A6.2.3 Procedure A6.2.4 Calculation A6.2.5 Reporting of Results APPENDIX A6.3 DETERMINATION OF THE RESISTANCE TO FRACTURE OF

MANHOLE COVRS AND GULLY GRATINGS A6.3.1 Scope A6.3.2 Equipment A6.3.3 Procedure A6.3.4 Reporting of results APPENDIX A6.4 TESTS ON GRAVITY PIPELINES FOR DRAINAGE WORKS A6.4.1 Scope A6.4.2 Equipment A6.4.3 Procedure: Before Tests and Inspections A6.4.4 Procedure: Water Test A6.4.5 Procedure: Air Test A6.4.6 Procedure: Visual Inspection A6.4.7 Procedure: Infiltration Test A6.4.8 Calculation A6.4.9 Reporting of results

Issue No. 4: January 2004 (iii) General Materials & Workmanship Specification

APPENDIX A6.5 TESTS ON PRESSURE PIPELINES FOR DRAINAGE WORKS A6.5.1 Scope A6.5.2 Equipment A6.5.3 Procedure A6.5.4 Calculation A6.5.5 Reporting of Results SECTION 7 EARTHWORKS 7.1 Definitions and Abbreviations 7.2 Materials 7.3 Submissions 7.4 Workmanship 7.5 Inspection, Testing and Commissioning APPENDIX A7.1 TEST METHODS FOR FILL MATERIAL A7.1.1 General A7.1.2 Terms and Symbols A7.1.3 Grouping of Material APPENDIX A7.2 DETERMINATION OF THE MOISTURE CONTENT OF FINE

GRAINED AND MEDIUM GRAINED MATERIAL BY THE MICROWAVE OVEN DRYING METHOD

A7.2.1 Scope A7.2.2 Apparatus A7.2.3 Procedure A7.2.4 Calculation A7.2.5 Reporting of Results APPENDIX A7.3 DETERMINATION OF THE IN-SITU BULK density AND THE

IN-SITU DRY DENSITY OF FINE GRAINED AND MEDIUM GRAINED MATERIAL BY THE NUCLEAR DENSOMETER METHOD

A7.3.1 Scope A7.3.2 Apparatus A7.3.3 Procedure: Comparability of Test Methods A7.3.4 Procedure: Routine Denosometer Check A7.3.5 Procedure: Determination of In-situ Bulk Density A7.3.6 Calculation A7.3.7 Reporting of Results APPENDIX A7.4 DETERMINATION OF THE MAXIMUM CONVERTED BULK

DENSITY BY THE HILF METHOD A7.4.1 Scope A7.4.2 Apparatus A7.4.3 Procedure A7.4.4 Calculation A7.4.5 Reporting of Results

Issue No. 4: January 2004 (iv) General Materials & Workmanship Specification

APPENDIX A7.5 ADJUSTMENT OF THE MAXIMUM CONVERTED BULK DENSITY FOR THE DETERMINATION OF THE RELATIVE COMPACTION

A7.5.1 Scope A7.5.2 Apparatus A7.5.3 Procedure A7.5.4 Calculation A7.5.5 Reporting of Results SECTION 8 GEOTECHNICAL WORKS 8.1 General Requirements 8.2 Trials for Geotechnical Works 8.3 Definitions and Abbreviations – Ground Investigation 8.4 Submissions – Ground Investigation 8.5 Workmanship – Ground Investigation 8.6 Inspection, Testing and Commissioning – Ground Investigation 8.7 Materials – Slope Treatment Works 8.8 Submissions – Slope Treatment Works 8.9 Workmanship – Slope Treatment Works 8.10 Inspection, Testing and Commissioning – Slope Treatment Works 8.11 Definitions and Abbreviations – Grouting for Geotechnical Works 8.12 Materials – Grouting for Geotechnical Works 8.13 Submissions – Grouting for Geotechnical Works 8.14 Workmanship – Grouting for Geotechnical Works 8.15 Inspection, Testing and Commissioning – Grouting for Geotechnical Works 8.16 Definitions and Abbreviations – Groundwater Drainage and Control 8.17 Materials– Groundwater Drainage and Control 8.18 Submissions – Groundwater Drainage and Control 8.19 Workmanship – Groundwater Drainage and Control 8.20 Inspection, Testing and Commissioning – Groundwater Drainage and Control 8.21 Definitions and Abbreviations – Geotechnical Instrumentation 8.22 Materials – Geotechnical Instrumentation 8.23 Submissions – Geotechnical Instrumentation 8.24 Workmanship – Geotechnical Instrumentation 8.25 General – Laboratory Work 8.26 Workmanship – Laboratory Work 8.27 Inspection, Testing and Commissioning – Laboratory Work APPENDIX A8.1 “GEO” PROBE TEST A8.1.1 Scope A8.1.2 Apparatus A8.1.3 Procedure A8.1.4 Reporting of Results APPENDIX A8.2 DETERMINATION OF THE FLOW OF GROUT A8.2.1 Scope A8.2.2 Apparatus A8.2.3 Procedure: Calibration A8.2.4 Procedure: Flow Test A8.2.5 Calculation A8.2.6 Reporting of Results

Issue No. 4: January 2004 (v) General Materials & Workmanship Specification

SECTION 9 CARRIAGEWAYS: SUB-BASE MATERIAL AND BITUMINOUS MATERIALS

9.1 Definitions and Abbreviations 9.2 Design and Performance Criteria 9.3 Materials 9.4 Submissions 9.5 Workmanship 9.6 Inspection, Testing and Commissioning APPENDIX A9.1 DETERMINATION OF THE PERMEABILITY OF FRICTION

COURSE MATERIAL A9.1.1 Scope A9.1.2 Apparatus A9.1.3 Procedure A9.1.4 Reporting of Results SECTION 10 CONCRETE CARRIAGEWAYS 10.1 General 10.2 Materials 10.3 Submissions 10.4 Workmanship 10.5 Inspection, Testing and Commissioning APPENDIX A10.1 DETERMINATION OF THE TEXTURE DEPTH OF

CARRIAGEWAYS A10.1.1 Scope A10.1.2 Materials A10.1.3 Apparatus A10.1.4 Procedure A10.1.5 Calculation A10.1.6 Reporting of Results SECTION 11 MISCELLANEOUS ROADWORKS 11.1 General 11.2 Design and Performance Criteria 11.3 Materials 11.4 Submissions 11.5 Workmanship 11.6 Inspection, Testing and Commissioning APPENDIX A11.1 DETERMINATION OF CHARACTERISTIC COMPRESSIVE

STRENGTH OF INTERLOCKING BLOCKS A11.1.1 Scope A11.1.2 Apparatus A11.1.3 Procedure A11.1.4 Calculation A11.1.5 Reporting of Results

Issue No. 4: January 2004 (vi) General Materials & Workmanship Specification

SECTION 12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS 12.1 General 12.2 Definitions and Abbreviations 12.3 Relevant Codes and Standards 12.4 Materials 12.5 Submissions 12.6 Workmanship 12.7 Inspection, Testing and Commissioning SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL

INSTALLATIONS 13.1 General 13.2 Materials 13.3 Workmanship 13.4 Inspection, Testing and Commissioning SECTION 14 WATER SUPPLY PIPEWORKS 14.1 General 14.2 Definitions and Abbreviations 14.3 Materials 14.4 Submissions 14.5 Workmanship 14.6 Inspection, Testing and Commissioning APPENDIX A14.1 PRESSURE TESTS ON PIPELINES A14.1.1 Scope A14.1.2 Equipment A14.1.3 Procedure A14.1.4 Calculation A14.1.5 Reporting of results

Issue No. 4: January 2004 1/19 General Materials & Workmanship Specification Volume 1 of 4

SECTION 1 ABBREVIATIONS, STANDARDS AND GENERAL 1.1 DEFINITIONS & ABBREVIATIONS 1.1.1 Definitions

Words and expressions to which meanings have been assigned in the General Conditions and General Specification, shall have the same meanings in this volume.

1.1.2 Abbreviations

Abbreviations in this volume shall have the following meanings:

ACI American Concrete Institution Standard

AOAC Association of Analytical Chemistry

APHA American Public Health Authority

ASSHTO American Association of State Highway and Transportation Officials

AWWA American Water Works Association

ASTM American Society for Testing and Material

BS British Standard

CCTV closed circuit television

CD chart datum

CI cast iron

CIRIA Construction Industry Research and Information Association

CP British Standard Code of Practice

CS Construction Standard

DI ductile iron

DN nominal size

Dn nominal size of tees and tapers

FGL finished ground level, or finished level of permanent works

GEO Geotechnical Engineering Office, Civil Engineering Department (Hong Kong

Government)

GGBFS Ground Granulated Blast Furnace Slag

GI galvanised iron

GRC glassfibre reinforced concrete

HDPE high density polyethylene

HOKLAS Hong Kong Laboratory Accreditation Scheme

HSFG high strength friction grip

ISO International Organisation for Standardization

OPC ordinary Portland cement

PD Principal Datum

PFA pulverised-fuel ash

PPFAC Portland pulverised-fuel ash cement

PNAP Practice Note for Authorised Persons and Registered Structural Engineers


Ppm parts per million

PTFE polytertrafluroethylene

PVC polyvinyl chloride

RHPC rapid hardening Portland cement

SIL Standard Inter-departmental Landscape Technical Group

SIS Swedish Standard

SRPC sulphate resisting Portland cement

UPVC Unplasticised polyvinyl chloride

1.2 RELEVANT CODES AND STANDARDS 1.2.1 General

The Standards and Codes of Practice specified in this section are listed below for information only. The Contractor shall comply with the edition of the Standard or Code of Practice listed in the text when stated, or the latest edition when no edition is listed. Where British Standards have been replaced by the new BS EN documents, the old BS number is retained in the text, with the new BS EN number listed below.

1.2.2 British Standards

BS 4 Structural steel sections

BS 4 : Part 1 : 1993 Specification for hot-rolled sections

BS 12 : 1989 (replaced by BS EN 197-1:2000)

Specification for Portland cements

BS 21 : 1985 Specification for pipe threads for tubes and fittings where pressure - tight joints are made on the threads (metric dimensions)

BS 29 : 1987(replaced by BS EN 10250-2:2000)

Specification for carbon steel forgings above 150 mm ruling section

BS 65 : 1988 (replaced by BS 65:1991)

Specification for vitrified clay pipes, fittings, joints and ducts

BS 144 : 1997 Wood preservation using coal tar creosotes

BS 373 :1986 Methods of testing small clear specimens of timber

BS 381C:1996 Specification for colours for identification, coding and special purposes

BS 410 : 1986 Specification for test sieves

BS 416 : 1990 Discharge and ventilating pipes and fittings, sand-cast or spun in cast iron

BS 417 : Part 2 : 1987 Specification for galvanized low carbon steel cisterns, cistern lids, tanks and cylinders - metric units

BS 427 : 1990 (replaced by BS EN ISO 6507-1-3:1998)

Method for Vickers hardness test and for verification of Vickers hardness testing machines

BS 434 : 1990 Bitumen road emulsions (anionic and cationic)


BS 434 : Part 1 : 1984 Specification for bitumen road emulsions

BS 434 : Part 2 : 1984 Code of practice for use of bitumen road emulsions

BS 443 :1990 (replaced by BS EN 10244-2:2001)

Specification for testing zinc coatings on steel wire and for quality requirements

BS 449 : Part 2 : 1969 Specification for the use of structural steel in building - metric units

BS 534 : 1990 Specification for steel pipes, joints and specials for water and sewage

BS 544 : 1969 Specification for linseed oil putty for use in wooden frames

BS 718 : 1985 (replaced by BS 718 : 1991)

Specification for density hydrometers

BS 729 : 1986(replaced by BS EN ISO 1461:1999)

Specification for hot dip galvanized coatings on iron and steel articles

BS 743 : 1970 (replaced by BS 6398:1983 , BS 6515:1984 and BS 8215:1991)

Specification for materials for damp-proof courses

BS 747 : 2000 Specification for roofing felts

BS 812 Testing aggregates

BS 812 : Part 1 : 1975 (replaced by BS EN 932-1:1997)

Methods for determination of particle size and shape


Methods for determination of physical properties


Chemical properties

BS 812 : Part 101 : 1984 Guide to sampling and testing aggregates


Methods for sampling

BS 812 : Part 103 Methods for determination of particle size distribution

BS 812 : Section 103.1 : 1985

Sieve tests

BS 812 : Section 103.2 : 1989

Sedimentation test

BS 812 : Part 105 Methods for determination of particle shape

BS 812 : Section 105.1 : 1989

Flakiness index

BS 812 : Section 105.2 : 1990

Elongation index of coarse aggregate



Methods for determination of aggregate crushing value (ACV)


Methods for determination of ten per cent fines value (TFV)


Method for determination of aggregate impact value (AIV)


Method for determination of aggregate abrasion value (AAV)

BS 864 : Part 2 : 1983 (replaced by BS EN 1254-1-2:1998)

Specification for capillary and compression fittings for copper tubes

BS 873 Road traffic signs and internally illuminated bollards

BS 873 : Part 1 : 1983 Methods of test


Specification for internally illuminated signs and external lighting luminaires

BS 873 : Part 6 : 1983 (replaced by BS EN 12899-1:2001

Specification for retroreflective and non-retroreflective signs

BS 873 : Part 7 : 1984 Specification for posts and fittings

BS 882 : 1992 Specification for aggregates from natural sources for concrete

BS 890 : 1995 Specification for building limes

BS 903 Physical testing of rubber

BS 903 : Part A1 1996 Determination of density

BS 903 : Part A2 : 1995(2002)

Determination of tensile stress-strain properties

BS 903 : Part A3 : 1995 Determination of tear strength (trouser, angle and crescent test pieces)

BS 903 : 1997 Determination of compression stress-strain properties

BS 903 : Part A5 : 1974 (replaced by BS ISO 2285:2001)

Determination of tension set

BS 903 : Part A6 : 1992(1998)

Determination of compression set after constant strain

BS 903 : Part A9 : 1988 Determination of abrasion resistance

BS 903 : Part A16 : 1999 Determination of the effect of liquids

BS 903 : Part A18 : 1973(1998)

Determination of equilibrium water vapour absorption


BS 903 : Part A19 : 1994 Heat resistance and accelerated ageing tests

BS 903 : Part A26 : 1994 Determination of hardness

BS 903 : Part A43 : 1990(2002)

Method for determination of resistance to ozone cracking (static strain test)

BS 903 : Part C2 : 1982(1995)

Determination of volume resistivity

BS 952 Glass for glazing

BS 952 : Part 1 :: 1995 Classification

BS 952 : Part 2 : 1980 Terminology for work on glass

BS 970 : Part 1 : 1983 (replaced by BS EN 10084:1998, BS EN 10085:2001, BS EN 10087:1999, BS EN 10095:1999 and BS EN 10250-4:2000)

General inspection and testing procedures and specific requirements for carbon, carbon manganese, alloy and stainless steels

BS 1004 : 1972 (1985) (replaced by BS EN 12844:1999 and BS EN 1774:1998)

Specification for zinc alloys for die casting and zinc alloy die casting

BS 1010 : Part 2 : 1973 Draw-off taps and above-ground stopvalves

BS 1014 : 1975 (1986) (replaced by BS EN 12878:1999)

Specification for pigments for Portland cement and Portland cement products

BS 1070 : 1973(2000) Specification for black paint (tar-based)

BS 1155 : 1992(1997) Specification for natural rubber compounds for extrusion

BS 1161 : 1977(1991) Specification for aluminium alloy sections for structural purposes

BS 1181 : 1999 Specification for clay flue linings and flue terminals

BS 1191 Specification for gypsum building plasters

BS 1191 : Part 1 :1973(1994) Excluding premixed lightweight plasters

BS 1194 : 1999 Specification for concrete porous pipes for under-drainage

BS 1199 and 1200 : 1976 (replaced by BS EN 13139:2002)

Specification for building sands from natural sources

BS 1203 : 2001 Specification for synthetic resin adhesives (phenolic and aminoplastic) for plywood

BS 1204 Synthetic resin adhesives (phenolic and aminoplastic) for wood

BS 1204 : Part 1 : 1979 (1991) (replaced by BS 1204:1993, BS EN 301:1992 and BS EN 302-1-4:1992)

Specification for gap-filling adhesives


BS 1212 Float operated valves

BS 1212 : Part 1 : 1990 Specification for piston type float operated valves (copper alloy body)(excluding floats)

BS 1212 : Part 2 : 1990 Specification for diaphragm type float operated valves (copper alloy body)(excluding floats)

BS 1212 : Part 3 : 1990 Specification for diaphragm type float operated valves (plastic bodied) for cold water services only (excluding floats)

BS 1247 : 1990 Manhole steps

BS 1336 : 1971(2002) Specification for knotting

BS 1369 Steel lathing for internal plastering and external rendering

BS 1369 : Part 1 : 1987(1994)

Specification for expanded metal and ribbed lathing

BS 1377 : 1990 Methods of test for soils for civil engineering purposes (as modified in accordance with GEO Report No. 36, entitled "Methods of Test for Soils in Hong Kong for Civil Engineering Purposes (Phase 1 Tests)", except for Clauses 7.39(1) & 9.43(5) where the year of edition remains to be 1975)

BS 1387 : 1985 (1990) Specification for screwed and socketed steel tubes and tubulars and for plain end steel tubes suitable for welding or for screwing to BS 21 pipe threads

BS 1400 : 1985 (replaced by BS EN 1982:1999)

Specification for copper alloy ingots and copper alloy and high conductivity copper castings

BS 1449 : Part 1 : 1983 (replaced by BS 1449-1.1-1.5:1991 and BS EN 10130:1991)

Specification for carbon and carbon-manganese plate, sheet and strip

BS 1449 : Part 2 : 1983 (replaced by BS EN 10029:1991, BS EN 10048:1997, BS EN 10051:1992 BS EN 10095:1999 BS EN 10258:1997 and BS EN 10259:1997)

Specification for stainless and heat-resisting steel plate, sheet and strip


Specification for flake graphite cast iron

BS 1470 : 1987 (replaced by BS EN 485-1-4:1994, BS EN 515:1993 and BS EN 573-1-4:1995)

Specification for wrought aluminium and aluminium alloys for general engineering purposes : plate, sheet and strip

BS 1471 : 1972 (replaced by BS EN 515:1993, BS EN 573-3-4:1995 and BS EN 754-1-2:1997,-7-8:1998)

Specification for wrought aluminium and aluminium alloys for general engineering purposes - drawn tube


BS 1473 : 1972 Specification for wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock

BS 1474 : 1987 (replaced by BS EN 515:1993, BS EN 573-3-4:1995, BS EN 755-1-9:1996 and BS EN 12020-1-2:2001)

Specification for wrought aluminium and aluminium alloys for general engineering purposes : bars, extruded round tubes and sections

BS 1494 : Part 2 : 1967 (withdrawn)

Sundry fixings

BS 1610 : 1985 (replaced by BE EN ISO 7500-1:1999, BS EN 10002-3:1995 and BS EN ISO 7500-2:1999)

Materials testing machines and force verification equipment


Method for specifying anodic oxidation coatings on aluminium and its alloys

BS 1722 : Part 1: 1999 Specification for chain link fences

BS 1740 : Part 1 : 1971 (1990) (replaced by BS EN 10241:2000)

Specification for wrought steel pipe fitting (screwed BS 21 R-series thread)

BS 1924 : 1990 Stabilized materials for civil engineering purposes

BS 2000 Methods of test for petroleum and its products

BS 2015 : 1965 (1985) (replaced by BS 2015 : 1992 (2000) and BS EN 971-1:1996)

Glossary of paint terms

BS 2451 : 1963 (1988) (replaced by BS EN ISO 11124-3:1997, BS 7079-4:1994)

Specification for chilled iron shot and grit

BS 2456: 1990 Specification for floats (plastics) for float operated valves for cold water services

BS 2494 : 1990 (replaced by BS 2494 : BS 7874:1998, BS EN 681-1-2:1996 and BS EN 682:2002)

Specification for elastomeric seals for joints in pipework and pipelines

BS 2499 1-3:1992 Specification for hot applied joint sealants for concrete pavements

BS 2523 : 1996(2000) Specification for lead-based priming paints

BS 2569 : Part 1 : 1964 (1988) (replaced by BS EN 22063:1994)

Protection of iron and steel by aluminium and zinc against atmospheric corrosion

BS 2600 Radiographic examination of fusion welded butt joints in steel


BS 2600 : Part 1 : 1983 (replaced by BS EN 1435:1997)

Methods for steel 2 mm up to and including 50 mm thick


Methods for steel over 50 mm up to and including 200 mm thick

BS 2633 : 1987(2001) Specification for Class I arc welding of ferritic steel pipework for carrying fluids

BS 2648 : 1995(2000) Performance requirements for electrically-heated laboratory drying ovens

BS 2760 : 1973 Specification for pitch-impregnated fibre pipes and fittings for below and above ground drainage

BS 2782 Methods of testing plastics

BS 2782 : Part 3 :

Methods 320A to 320F : 1976(1996)

Tensile strength, elongation and elastic modulus

BS 2782 : Part 3 :

Method 365A : 1976(2002)

Determination of softness number of flexible plastics materials

BS 2782 : Part 3 :

Method 365D : 1997

Determination of hardness of plastics and ebonite by the ball indentation method

BS 2782 : Part 4 :

Methods 430A to 430D : 1983

Determination of water absorption at 23°C.

Determination of water absorption at 23°C with allowance for water-soluble matter.

Determination of boiling water absorption.

Determination of boiling water absorption with allowance for water-soluble matter.

BS 2782 : Part 6 :

Methods 620A to 620D : 1980 (replaced by BS 2782 : Part 6 : Methods 620A to 620D : 1991 and BS EN ISO 1183-3:1999)

Determination of density of solid plastics excluding cellular plastics (immersion method).

Determination of density of solid plastics excluding cellular plastics (pyknometer method).

Determination of plastics (sink-float method).

Determination of density of solid plastics excluding cellular plastics (density gradient column method).


Specification for spheroidal graphite or nodular graphite cast iron

BS 2846 : Part 3 : 1975 (1985)

Determination of a statistical tolerance interval

BS 2846 : Part 4 : 1976 (1985)

Techniques of estimation and tests relating to means and variances

BS 2869 : Part 2 : 1998 Specification for fuel oil for agricultural and industrial engines and burners (classes A2, C1, C2, D, E, F, G and H)



Copper tubes for water, gas and sanitation

BS 2874 : 1986 (replaced by BS EN 12163:1998, BS EN 12164:1998 and BS EN 12167:1998)

Specification for copper and copper alloy rods and sections (other than forging stock)


Methods for radiographic examination of fusion welded circumferential butt joints in steel pipes


Specification for continuously hot-dip zinc coated and iron-zinc alloy coated steel : wide strip, sheet/plate and slit wide strip


Specification for TIG welding of aluminum, magnesium and their alloys

BS 3049 : 1995 Specification for pedestrian guard rails (metal)

BS 3100 : 1991(2001) Specification for steel castings for general engineering purposes

BS 3148 : 1980 Methods of test for water for making concrete (including notes on the suitability of the water)


Specification for constituent materials and mixtures


Specification for application of material to road surfaces

BS 3382 : Part 1 and 2 1961(1998)

Cadmium on steel components. Zinc on steel components

BS 3410 : 1961 Specification for metal washers for general engineering purposes

BS 3416 : 1988(2000) Specification for bitumen-based coatings for cold application, suitable for use in contact with potable water

BS 3468 : 1986 Specification for austenitic cast iron

BS 3505 : 1986 (replaced by BS EN 1452-1-5:2000)

Specification for unplasticized polyvinyl chloride (PVC-U) pressure pipes for cold potable water

BS 3506 : 1969 Specification for unplasticized PVC pipe for industrial uses


Specification for MIG welding of aluminium and aluminium alloys

BS 3600 : 1976 (1988) (replaced by BS 3600 : 1997)

Specification for dimensions and masses per unit length of welded and seamless steel pipes and tubes for pressure purposes

BS 3601 : 1987(1993) Specification for carbon steel pipes and tubes with specified room temperature properties for pressure purposes


BS 3690 : Part 1 : 1989 (replaced by BS 3690 : Part 1 : 1989 and BS EN 12591:2000)

Specification for bitumens for roads and other paved areas

BS 3690 : Part 2 : 1989 (replaced by BS 3690 : Part 2 : 1989(1997))

Specification for bitumens for industrial purposes

BS 3692 : 1967 (replaced by BS 3692 : 2001)

Specification for ISO metric precision hexagon bolts, screws and nuts. Metric units

BS 3698 : 1964 (1979) (replaced by BS 3698 : 1964(2000))

Specification for calcium plumbate priming paints

BS 3892 : Part 1 : 1997 Specification for pulverized-fuel ash for use as a cementitious component in structural concrete

BS 3900 : Part E10 : 1979 (1989) (replaced by BS EN 24624:1993(2000))

Mechanical tests on paint films – Pull-off test for adhesion


Methods for manual examination of fusion welds in ferritic steels

BS 3923 : Part 2 : 1972 Automatic examination of fusion welded butt joints in ferritic steels

BS 3981 : 1976(2000) Specification. Iron oxide pigments for paints

BS 3987 : 1991 Specification for anodic oxide coatings on wrought aluminium for external architectural applications

BS 3998 : 1989 Recommendations for tree work

BS 4027 : 1996 Specification for sulphate-resisting Portland cement

BS 4072 : 1999 Wood preservation by means of copper/chromium/arsenic compositions

BS 4102 : 1990 and BS EN 10223-1,-4-6:1998

Specification for steel wire and wire products for fences

BS 4147 : 1980 (1987) Specification for bitumen-based hot-applied coating materials for protecting iron and steel, including suitable primers where required

BS 4168 : Part 1 : 1981 (replaced by BS EN ISO 4762:1998)

Specification for hexagon socket head cap screws

BS 4190 : 2000 Specification for ISO metric black hexagon bolts, screws and nuts

BS 4211 : 1994 Specification for ladders for permanent access to chimneys, other high structures, silos and bins


BS 4232 : 1967 (replaced by BS 7079-0:1990, BS 7079-A1:1989, ISO 8501-1:1988, BS 7079:Part A1:Supplement 1:1989, BS EN ISO 8503-1:1995, BS 7079-C1:1989, BS EN ISO 8503-2:1995, BS 7079-C2:1989, BS EN ISO 8503-3:1995, BS 7079-C3:1989, BS EN ISO 8503-4:1995, BS 7079-C4:1989(1998))

Specification for surface finish of blast-cleaned steel for painting

BS 4254 : 1983 Specification for two-part polysulphide-based sealants

BS 4320 : 1968 Specification for metal washers for general engineering purposes. Metric series

BS 4345 : 1968 (1986) Specification for slotted angles

BS 4346 Joints and fittings for use with unplasticized PVC pressure pipes


Injection moulded unplasticized PVC fittings for solvent welding for use with pressure pipes, including potable water supply


Mechanical joints and fittings, principally of unplasticized PVC


Specification for solvent cement

BS 4360 : 1986 (replaced by BS 7613:1994, BS 7668:1994, BS EN 10029:1991, BS EN 10113-1-3:1993, BS EN 10155:1993 and BS EN 10210-1:1994)

Specification for weldable structural steels

BS 4393 : 1969 (1985) (replaced by BS 4393 : 1991)

Specification for tin or tin-lead coated copper wire

BS 4395 Specification for high strength friction grip bolts and associated nuts and washers for structural engineering

BS 4395 : Part 1 : 1969(1998)

General grade

BS 4395 : Part 2 : 1969(1998)

Higher grade bolts and nuts and general grade washers

BS 4395 : Part 3 : 1973 Higher grade bolts (waisted shank), nuts and general grade washers


BS 4449 : 1978 (1984) (excluding AMD 4337 and AMD 4540 and clauses 12.2.1 and 12.2.2) (replaced by BS 4449:1997)

Specification for hot rolled steel bars for the reinforcement of concrete

BS 4461 : 1997 Specification for cold worked steel bars for the reinforcement of concrete

BS 4446 : 1989 (replaced by BS 8666:2000 and BS EN ISO 4066:2000)

Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete

BS 4482 : 1985 Specification for cold reduced steel wire for the reinforcement of concrete

BS 4483 : 1985 Specification for steel fabric for the reinforcement of concrete

BS 4486 : 1980 Specification for hot rolled and hot rolled and processed high tensile alloy steel bars for the prestressing of concrete

BS 4504 : Section 3.1 : 1989 (replaced by BS EN 1092-1:2002, BS EN 1515-1:2000)

Circular flanges for pipes, valves and fittings (PN designated) - Specification for steel flanges

BS 4514 : 2001 Specification for unplasticized PVC soil and ventilating pipes, fittings and accessories

BS 4515 : 1984 (BS 4515 : 2000)

Specification for welding of steel pipelines on land and offshore


Methods of testing cement – Sampling

BS 4550 : Part 2 : 1970 Methods of testing cement – Chemical tests

BS 4550 : Part 3 : 1978 Methods of testing cement – Physical tests

BS 4551 : 1980 Methods of testing mortars, screeds and plasters

BS 4568 Specification for steel conduit and fittings with metric threads of ISO form electrical installations

BS 4568 : Part 1 : 1970 Steel conduit, bends and couplers

BS 4568 : Part 2 : 1970 (1988) (replaced by BS EN 50086-1:1994)

Fittings and components

BS 4570 : 1985 Specification for fusion welding of steel castings

BS 4576 : Part 1 : 1989, BS EN 607:1996, BS EN 1462:1997 and BS EN 12200-1:2000

Unplasticized polyvinyl chloride (PVC-U) rainwater goods and accessories - Half-round gutters and pipes of circular cross-section

BS 4604 Specification for the use of high strength friction grip bolts in structural steelwork

BS 4604 : Part 1 : 1970 General grade


BS 4604 : Part 2 : 1970 Higher grade (parallel shank)

BS 4620 : 1970 (1988) Specification for rivets for general engineering purposes

BS 4622 : 1970 (1983) Specification for grey iron pipes and fittings

BS 4652 : 1970(2000) Specification for metallic zinc-rich priming paint (organic media)

BS 4660 : 2000 Specification for unplasticized polyvinyl chloride (PVC-U) pipes and plastics fittings of nominal sizes 110 and 160 for below ground gravity drainage and sewerage

BS 4662 : 1970 (1989) Specification for boxes for the enclosure of electrical accessories

BS 4677 : 1984(2001) Specification for arc welding of austenitic stainless steel pipework for carrying fluids

BS 4756 : 1998 Specification for ready mixed aluminium priming paints for woodwork

BS 4772 : 1988 (replaced by BS 4772 : BS EN 545:1995, BS EN 598:1995 and BS EN 969:1996)

Specification for ductile iron pipes and fittings

BS 4848 Specification for hot-rolled structural steel sections


Hollow sections


Equal and unequal angles


Bulb flats


Specification for non-metallic flat gaskets (including gaskets for flanges to BS 4772)


Specification for approval testing of welding procedures - Fusion welding of steel


Specification for approval testing of welders working to approved welding procedures - Fusion welding of steel

BS 4872 : Part 1 : 1982(1999)

Specification for approval testing of welders when welding procedure approval is not required - Fusion welding of steel

BS 4873 : 1986 Specification for aluminium alloy windows

BS 4921 : 1988(1994) Specification for sheradized coatings on iron or steel

BS 4933 : 1973 Specification for ISO metric black cup and countersunk head bolts and screws with hexagon nuts


BS 4942 : 1981 (replaced by BS EN 818-1:1996, BS EN 818-3:1999 and BS EN 818-7:2002)

Short link chain for lifting purposes

BS 5075 : Part 1 : 1982, BS EN 480 and BS EN 934

Specification for accelerating admixtures, retarding admixtures and water reducing admixtures

BS 5075 : Part 3 : 1985, BS EN 480 and BS EN 934

Specification for superplasticizing admixtures

BS 5135 : 1984 (replaced by BS EN 1011-1:1998 and BS EN 1011-2:2001)

Specification for arc welding of carbon and carbon manganese steels

BS 5150 : 1990 Specification for cast iron gate valves

BS 5154 : 1991 Specification for copper alloy globe, globe stop and check, check and gate valves

BS 5163 : 1986 1986(1991) Specification for predominantly key-operated cast iron gate valves for waterworks purposes

BS 5212 : 1990 Cold applied joint sealant systems for concrete pavements

BS 5215 : 1986 Specification for one-part gun grade polysulphide-based sealants

BS 5252F : 1976 (1986) (replaced by BS 5252F : 1976(2002))

Colour matching fan

BS 5255 : 1989, BS EN 1329-1:2000, BS EN 1455-1:2000, BS EN 1519-1:2000, BS EN 1565-1:2000 and BS EN 1566-1:2000

Specification for thermoplastics waste pipe and fittings

BS 5268 : Part 2 : 2002 Structural use of timber - Code of practice for permissible stress design, materials and workmanship

BS 5284 : 1993 Methods. Sampling and testing mastic asphalt and pitchmastic used in building

BS 5289 : 1976 (1983) (replaced by BS EN 970:1997)

Code of practice. Visual inspection of fusion welded joints

BS 5395 : Part 1 :2000 Code of practice for the design of straight stairs

BS 5400 Steel, concrete and composite bridges

BS 5400 : Part 2 : 1978, BS 5400-9.1-9.2:1983

Specification for loads

BS 5400 : Part 4 : 1990 Code of practice for design of concrete bridges

BS 5400 : Part 6 : 1980 Specification for materials and workmanship, steel

BS 5400 : Part 9 : 1983 Bridge bearings

BS 5400 : Section 9.2 : 1983 Specification for materials, manufacture and installation of bridge bearings


BS 5481 : 1977 (1989) (replaced by BS EN 1401-1:1998)

Specification for unplasticized PVC pipe and fittings for gravity sewers

BS 5493 : 1977, BS EN ISO 12944-1-8:1998 and BS EN ISO 14713:1999

Code of practice for protective coating of iron and steel structures against corrosion

BS 5573 : 1996 Code of practice for safety precautions in the construction of large diameter boreholes for piling and other purposes

BS 5589 : 1989(1997) Code of practice for preservation of timber

BS 5756 : 1997 Specification for tropical hardwoods graded for structural use

BS 5896 : 1980 Specification for high tensile steel wire and strand for the prestressing of concrete

BS 5911 Precast concrete pipes, fittings and ancillary products

BS 5911 : Part 2 : 1982 Specification for inspection chambers and street gullies

BS 5911 : Part 3 : 1982 (replaced by BS 5911-110:1992)

Specification for pipes and fittings with ogee joints

BS 5911 : Part 100 : 1988 Specification for unreinforced and reinforced pipes and fittings with flexible joints

BS 5911 : -200:1994 Specification for unreinforced and reinforced manholes and soakaways of circular cross section

BS 5930 : 1981 (replaced by BS 5930 : 1999)

Code of practice for site investigations

BS 5931 : 1980 Code of practice for machine laid in situ edge details for paved areas

BS 5950 -2:2001 Specification for materials, fabrication and erection : hot rolled sections


Methods for ultrasonic testing and specifying quality grades of ferritic steel plate

BS 6044 : 1987 (replaced by BS EN 1436:1998 and BS EN 1871:2000)

Specification for pavement marking paints

BS 6072 : 1981 (1986) (replaced by BS EN ISO 9934-1:2001)

Method for magnetic particle flaw detection

BS 6088 : 1981 (1985) (replaced by BS 6088:1981(1993) and BS EN 1423:1998)

Specification for solid glass beads for use with road marking compounds and for other industrial uses

BS 6089 : 1981 Guide to assessment of concrete strength in existing structures

BS 6105 : 1981 (replaced by BS EN ISO 3506-1-2:1998)

Specification for corrosion-resistant stainless steel fasteners


BS 6150 : 1991 Code of practice for painting of buildings

BS 6262-4: 1994 Code of practice for glazing for buildings

BS 6323 : 1982 (1990) Specification for seamless and welded steel tubes for automobile, mechanical and general engineering purposes

BS 6323 : Part 1 : 1982 (1990)

General requirements

BS 6323 : Part 3 : 1982 (1990)

Specific requirements for hot finished seamless steel tubes

BS 6323 : Part 8 : 1982 (1990)

Specific requirements for longitudinally welded stainless steel tubes

BS 6349 1:2000 Code of practice for maritime structures – General criteria

BS 6362 : 1990(2001) Specification for stainless steel tubes suitable for screwing in accordance with BS 21 'Pipe threads for tubes and fittings where pressure-tight joints are made on the threads'

BS 6405 : 1984(1998) Specification for non-calibrated short link steel chain (grade 30) for general engineering purposes : class 1 and 2

BS 6431 Ceramic floor and wall tiles

BS 6431 : Part 1 : 1983(1996)

Specification for classification and marking, including definitions and characteristics

BS 6431 : Part 2 : 1984(1996)

Specification for extruded ceramic tiles with a low water absorption (E 3%). Group A1

BS 6431 : Part 3 Extruded ceramic tiles with a water absorption of 3% < E 6%. Group A11a

BS 6431 : Part 3 : Section 3.1 : 1986(1996)

Specification for general products

BS 6431 : Part 3 : Section 3.2 : 1986(1996)

Specification for products (terre cuite, cotto, baldosin catalan)

BS 6431 : Part 4 Extruded ceramic tiles with a water absorption of 6% < E 10%. Group A11b

BS 6431 : Part 4 : Section 4.1 : 1986(1996)

Specification for general products

BS 6431 : Part 4 : Section 4.2 : 1986(1996)

Specification for specific products (terre cuite, cotto, baldosin catalan)


Method for penetrant flaw detection

BS 6463 Quicklime, hydrated lime and natural calcium carbonate

BS 6463 -101:1996 Methods of sampling

BS 6463 -102:2001 Methods of chemical analysis

BS 6463 -103:1999 Methods of test for physical properties of hydrated lime and lime putty

BS 6510 : 1984 Specification for steel windows, sills, window boards and doors


BS 6558 : 1985 (replaced by BS EN 187000:1994 and BS EN 187000:1994)

Optical fibres and cables

BS 6566 (replaced by BS EN 636-1-3:1997)

Plywood


Specification for Portland pulverized-fuel ash cement

BS 6657 : 1991 Guide for prevention of inadvertent initiation of electro-explosive devices by radio-frequency radiation


Specification for malleable cast iron

BS 6700 : 1997 Specification for design, installation, testing and maintenance of services supplying water for domestic use within buildings and their cartilages

BS 6925 : 1988 Specification for mastic asphalt for building and civil engineering (limestone aggregate)

BS 6949 : 1991(2000) Specification for bitumen-based coatings for cold application, excluding use in contact with potable water

BS 7295 Fusion bonded epoxy coated carbon steel bars for the reinforcement of concrete

BS 7263 : 1990 Precast concrete flags, kerbs, channels, edgings and quadrants

BS 7263 : Part 1 : 1990 (replaced by BS 7263-1:2001 and BS 7263-3:2001)

Specification

BS 8004 : 1986 Code of practice for foundations


Guide to new sewerage construction

CP 144 Roof coverings

CP 144 : Part 4 : 1970 (replaced by BS 8218:1998)

Mastic asphalt. Metric units

1.2.3 American Standards

AASHTO Designation M252-81

Standard specification for corrugated polyethylene drainage tubing

ASTM A 775M (replaced by ASTMa775m-01)

Specification for epoxy-coated reinforcing steel bars

ASTM C 127-88 (replaced by ASTMC127-01)

Test method for specific gravity and absorption of coarse aggregate

ASTM C 128-88 (replaced by ASTM C128-01)

Test method for specific gravity and absorption of fine aggregate


ASTM C 138-81 (1987) (replaced by ASTM C131-01)

Test method for resistance to degradation of small-size coarse aggregate by abrasion and impact in the Los Angeles Machine

ASTM C 136-84A (replaced by ASTM c136-01)

Method for sieve analysis of fine and coarse aggregates

ASTM C 188-84 (replaced by ASTM c188-95)

Test method for density of hydraulic cement

ASTM C 939-87 (replaced by ASTM c939-97)

Test method of flow of grout for preplaced-aggregate concrete

ASTM D 5-86 (replaced by ASTM d5-97)

Test method for penetration of bituminous materials


Test method for ductility of bituminous materials


Method for sampling bituminous materials

ASTM D 242-85 (replaced by ASTM d242-95(2000)e1)

Specification for mineral filler for bituminous paving mixtures

ASTM D 546-88 (replaced by ASTM d546-99e1)

Method for sieve analysis of mineral filler for road and paving materials

ASTM D 854-83 (replaced by ASTM d854-00e1)

Test method for specific gravity of soils

ASTM D 946-82 (replaced by ASTM d946-82(1999))

Specification for penetration-graded asphalt cement for use in pavement construction


Methods for sampling bituminous paving mixtures

ASTM D 1559-82 (replaced by ASTM (discontinued))

Test method for resistance to plastic flow of bituminous mixtures using Marshall apparatus


Test method for effect of heat and air on asphaltic materials (thin-film over test)


Classification system for rubber products in automobile applications

ASTM D 2027-76 (1986) (replaced by d2027-97)

Specification for cutback asphalt (medium-curing type)

ASTM D 2041-78 (replaced by d2041-00)

Test method for theoretical maximum specific gravity of bituminous paving mixtures

ASTM D 2042-81 (1985) (replaced by d2042-01)

Test method for solubility of asphalt materials in trichloroethylene


Test method for viscosity of asphalts by vacuum capillary

ASTM D 2172-88 (replaced by d2172-01e1)

Test method for quantitative extraction of bitumen from bituminous paving mixtures


Test method for bulk specific gravity of compacted bituminous mixtures using saturated surface-dry specimens


ASTM D 3203-88 (replaced by d3203-94(2000))

Test method for percent air voids in compacted dense and open bituminous paving mixtures


Test method for specific gravity or density of semi-solid and solid bituminous materials by nickel crucible

AWWA C 203-86 Coal-tar enamel protective coatings for steel water pipes

1.2.4 Hong Kong Government Publications

CS1 : 1990 Testing concrete

CS2 : 1995 Carbon steel bars for the reinforcement of concrete

Geospec 1 Model specification for prestressed ground anchors, 2nd edition (1989)

Geospec 3 Model specification for soil testing

Geoguide 1 Guide to retaining wall design 2nd Edition

Geoguide 2 Guide to site investigation (1987)

Geoguide 3 Guide to rock and soil descriptions (1988)

Geoguide 6 Guide to reinforced fill structure and slope design

GEO Report No.36

Methods of test for soils in Hong Kong for civil engineering purposes (Phase 1) tests (1994)

GCO 1/90 Review of design methods for excavation

GCO 1/96 Pile design and construction

Geotechnical manual for slopes, 2nd Edition

Stormwater drainage manual

Sewerage manual (Part 1) – Key planning issues and gravity collection system

Sewerage manual (Part 2) – Pumping station and rising mains

Drainage services department standard drawings

Transport planning and design manual

Code of practice for lighting, signing and guarding of road works

Public lighting design manual

Structures design manual for highways and railways

Guidelines on design of noise barriers

Highways standard drawings

Civil Engineering design manual

Civil Engineering Department standard drawings

PNAP1 – Building Department practice notes in force 1.2.5 Other International Standards

SIS 05 59 00 Surface preparation standard for painting steel surfaces


SECTION 2 TEMPORARY WORKS 2.1 INTRODUCTION

This Section specifies materials and workmanship required for the design and construction of Temporary Works.

2.2 DESIGN AND PERFORMANCE CRITERIA 2.2.1 Design

(a) Unless otherwise stated in the Contract, Temporary Works shall be designed by the Contractor who shall submit for the Project Manager's review copies of calculations and drawings of the Temporary Works in accordance with the requirements stated in the Contract.

(b) The Contractor shall design Temporary Works in accordance with the principles of

BS 5975 except that the criteria as set out in Appendix A2.2 shall prevail when designing for Hong Kong conditions.

(c) Where appropriate, Temporary Works design shall comply with the requirements of

the Building Ordinance.

2.2.2 Temporary Works Co-ordinator

(a) The Contractor shall appoint a person "the Temporary Works Co-ordinator" whose duties shall in general follow the recommendations of Clause 10.2.2 of BS 5975. The Contractor shall submit for review by the Project Manager the details and duties of the Temporary Works Co-ordinator.

(b) The Temporary Works Co-ordinator shall certify the design, loading, and dismantling

of falsework in accordance with Appendices A2.2 and A2.3. 2.2.3 Checking Engineer

Unless the Contract provides expressly to the contrary, the design of the Temporary Works shall be checked and certified as being satisfactory by the Checking Engineer in accordance with Appendices A2.2 and A2.3; and all the certificates endorsed by the Checking Engineer in relation thereto shall be submitted to the Project Manager for review.

2.2.4 Method

The Contractor shall submit for the Project Manager's review, method statements giving full details of materials, Contractor's Equipment and timing and sequence of operations involved in the construction of Temporary Works.

2.2.5 Construction and Removal

(a) Temporary Works shall be constructed to the same workmanship and quality standards as the Permanent Works save that the Temporary Works need not be new.

(b) The Contractor shall ensure that the Temporary Works are constructed, used and

removed in accordance with the certified design. If the Contractor wishes to change the construction, use or removal of the Temporary Works he shall submit to the


Project Manager for review details of such changes together with further certification in accordance with Appendices A2.2 and A2.3. Such details shall be reviewed without objection by the Project Manager before the Contractor implements any such change.

(c) Erection of falsework may not commence until the design has been certified by the

Temporary Works Co-ordinator and the Checking Engineer in accordance with Appendix A2.2.

(d) Loading or dismantling of falsework may not commence prior to certification by the

Temporary Works Co-ordinator and the Checking Engineer in accordance with Appendix A2.3.

(e) Temporary Works whether above or below ground or water level shall be dismantled

and completely removed after completion of the Permanent Works as shown on the Contractor's Drawings unless otherwise shown on the Employer's Drawings.

2.2.6 Scaffolding and Staging

(a) Scaffolding and staging shall be provided and erected in accordance with the Construction Sites (Safety) Regulations (Cap. 59). In addition, all walkways and elevated working platforms shall have properly constructed kickboards and handrailing.

(b) The use of "bamboo" for scaffolding or staging shall not be permitted without the

prior consent of the Project Manager and if permitted shall be subject to compliance with the requirements of the Construction Site (Safety) Regulations in relation to Scaffold, Working Platforms and Ladders.

2.2.7 Sheet Piling and Trench Support Systems

(a) Sheet piles shall be of the interlocking type and shall be of a suitable class for a particular location.

(b) Sheet piles shall be rolled from mild steel complying BS 4360. Each pile shall be in

one length throughout but where required may be extended by welding an additional length subject to the permission of the Project Manager. Welding shall be in accordance with the requirements of Section 22 of this General Materials and Workmanship Specification.

(c) Holes in the piling for ties and attachment of waling etc. shall be drilled after driving.

Burning of holes shall not be carried out without the permission of the Project Manager.

(d) The sheet piles shall be driven to the line and to the tolerances shown on the

Temporary Works drawings and shall be pitched in panels.

(e) Propriety trench support systems shall be reviewed without objection by the Project Manager prior to use on Site. Propriety systems shall be installed in accordance with the manufacturers recommendations and shall comply with CIRIA Technical Note 95; 1986.


2.2.8 Anchors

(a) Where the Contractor proposes to use anchors as part of his Temporary Works he shall, as part of his method statement, submit to the Project Manager for review a detailed specification for the anchors based on the current edition of the Government publication: Geospec 1, Model Specification for Ground Anchors, and shall include in the relevant quality plan a detailed scheme for installation of the anchors. Work shall not commence on Site until the Project Manager has reviewed without objection the Contractor's proposals. Anchors may be subject to the approval of the Building Ordinance Office and/or the Geotechnical Engineering Office and the Contractor must take full cognizance of the time required for the approval procedure in such a case.

(b) As soon as progress of the Works permits, and with the permission of the Project

Manager, temporary ties shall be destressed and as far as is practicable, physically severed from any part of the Works.

2.2.9 Temporary Piling

Piling to Temporary Works shall not adversely affect the geotechnical properties of the strata on which foundations for Permanent Works are to be constructed. Temporary Works piling adjacent to or in the near vicinity of foundations for Permanent Works shall be subject to the review of the Project Manager.

2.2.10 Temporary Decking

(a) Temporary deck panels, unless of concrete construction, shall have an anti-skid surface such as a graded calcined bauxite aggregate bedded in epoxy resin. The skid resistance value of the surface shall be in excess of 45, measured in accordance with BS 3262.

(b) The drainage of the temporary deck shall be such that all the surface water shall be

retained within the plan area of the temporary deck and be discharged properly and effectively through connections to the existing drainage system.

(c) The finished level, falls and camber of the temporary deck shall be in accordance with

the existing roadway. Walkways, which shall be drained properly and effectively, shall be provided to replace existing pavements which are overlapped by the temporary decking. Where walkways are covered they shall be lit for pedestrian safety.

(d) Minimum standard headroom under temporary structures shall be 5.1 m over

highways and roadways and 2.3 m over footpaths. Lighting of roadways covered by temporary structures shall be provided in accordance with the requirements for temporary lighting detailed in Section 3 of the General Specification.

2.2.11 Dewatering of Excavations, Drainage and Pumping

(a) The Contractor shall install, operate and maintain all temporary pumping plant and drainage facilities and remove all accumulated silt and debris necessary for the proper execution and completion of the Works.

(b) Groundwater control and drawdown shall be in accordance with the requirements of

Clauses 8E.4.16-8E.4.19 of this General Materials and Workmanship Specification.


2.2.12 Fire Hazard

All materials which present a fire hazard or which may give off noxious fumes in the event of ignition will be rejected for use in the Temporary Works and the Contractor shall immediately remove such materials from Site.

2.2.13 Welding

The Contractor's Equipment used for welding shall be in accordance with the appropriate British Standard and the safety regulations applicable in Hong Kong Construction Safety Regulations. Welding shall be carried out in compliance with Section 22 of this General Materials and Workmanship Specification.


APPENDIX A2.1

TEMPORARY WORKS DESIGN CRITERIA A2.1.1 Preamble This Appendix specifies the criteria which shall be used for the design of Temporary Works. A2.1.2 Ground Movement (1) The design of the Temporary Works shall investigate, evaluate and define acceptable

limits for ground movement within and around the Site and thereby avoid damage to adjacent property, land footways, roads and utilities.

(2) The installation of any wall (prior to dewatering and excavation) shall not produce

settlement in the adjacent ground or buildings greater than 25 mm. No dewatering will be permitted during the wall installation. In general, dewatering of an excavation will not be permitted until a closed perimeter of impermeable wall is completed.

(3) The Contractor shall establish an adequate number of settlement monitoring points on

both the front and back of adjacent land. Readings at appropriate intervals shall be continued throughout the duration of the Contract. If any of the following criteria are reached, irrespective of whether or not damage has occurred, the Contractor shall notify the Project Manager immediately:

(a) 5 mm - settlement between consecutive readings; (b) angular distortion exceeding 1/1000; or (c) 25 mm - total settlement of any part of a building or other structure. These requirements are in addition to any other requirements which may be required

by the Contract. A2.1.3 Ground Water The ground water level at the Airport may be at or near to ground level and the effect of

ground water must be taken into account in the design of Temporary Works. A2.1.4 Construction Method The design of Temporary Works shall take full account of the proposed construction

method. The Temporary Works drawings and calculations shall demonstrate the adequacy of the proposed construction method at each construction stage.

A2.1.5 Loads and Forces The design of Temporary Works shall take account of all the applied external forces and

imposed structural deformations.


A2.1.6 Excavation (1) The Temporary Works design shall take into account the temporary condition when

the excavation nears the bottom of permanent or temporary retaining walls. Unless otherwise stated on the Employer's Drawings, the factors of safety against base failure from bottom heave, failure from inward yielding, failure from piping or blows, shall be a minimum value of 1.5.

(2) The design of Temporary Works associated with earthworks, including temporary

slopes, stockpiles and drainage, shall be such that the risk of failure is not more than that which would be adopted if the Temporary Works were to be permanent. Allowance may be made in the design of the Temporary Works for the shorter design life and for the risk to persons and property and the surface water and groundwater conditions which are likely to occur during construction.

A2.1.7 Design Life The design of Temporary Works may take into account the limited duration over which the

Temporary Works are expected to function. Drawings submitted by the Contractor shall make clear where provision for limited life has been taken into account, particularly where this may have an influence on the stability of the Temporary Works.

A2.1.8 Cofferdams and Temporary Retaining Walls (1) The type of cofferdam and retaining wall proposed shall be suitable for the designed

purpose, taking into account the ground and other local conditions. (2) Calculations shall be carried out in accordance with the relevant British Standards. (a) For loads, the following shall apply : (i) the influence of wind, temperature, settlement, creep and the like shall be

taken into account; (ii) the applied load shall be calculated as accurately as possible; (iii) the most onerous load combination shall be obtained; (iv) the primary load resisting system shall be designed at basic permissible

stress; and (v) the secondary load resisting system may be designed with permitted

overstress. (b) All materials used as load carrying elements shall conform to the relevant

British Standard. The design shall be based on the basic permissible stresses as recommended in the relevant British Standard and the Building (Construction) Regulations (Cap. 123) where appropriate.

(c) Materials not conforming with the relevant British Standard may be used, but

only if the yield stress can be established. In this case the basic permissible stresses shall be calculated by applying the same partial safety factor on that yield stress as used in the relevant British Standard.


(3) Where the loading combination can be assessed with confidence, overstressing to 25% greater than the basic permissible stress may be permitted, except for the most onerous load combination condition or when the excavation is at its lowest level. Overstress may also be allowed for abnormal or extreme load calculations, when calculating the most onerous condition, which have a low probability of concurrent occurrence. For these latter two conditions, overstressing of the primary support system of walling and struts shall not be allowed.

(a) An overstress of 25% greater than the basic permissible stresses may be

allowed on a secondary load resisting system, such as steel sheet piles, provided that a method exists to rectify the system if over deflection or similar signs of distress become apparent.

(b) The following materials and sections in cofferdams may be overstressed by the

amounts stated:

(i) steel sheet piling: 25% increase in allowable bending and shear stresses; (ii) steel walings: for transient loads a 25% increase in allowable bending and

shear stresses; and (iii) reinforced concrete walings: 25% overstress during the early stages of

excavation and during the installation of frames.

(c) Overstressing shall not be allowed in struts (concrete or steel) or H-piles supporting lateral loads (concrete, steel or timber).

(d) Struts require a factor of safety of 2 against buckling. Calculated strut loads

shall be further increased by the load induced due to a temperature change of 34°C.

(e) Tendons for ground anchors shall not be stressed to greater than 64% of their

nominal failure load.

(4) The design and construction of a cofferdam shall limit ground movement around the Site and avoid damage to adjacent property, roads, footways and utilities.

(a) Settlement of adjoining structures, resulting from lateral deflection of the

waling systems, shall not exceed 25 mm. (b) During dewatering the piezometric pressure in the soil level effectively

supporting the adjacent property shall be maintained. This piezometric pressure may be lowered by a maximum of 2 m.

A2.1.9 Temporary Decks and Pedestrian Bridges (1) The design of temporary decks which are required to carry traffic shall be carried out

by:

(a) using HA highway loading; (b) obtaining the most onerous load combination; and (c) checking with 22.5 units HB highway loading.

Where loads from Contractor's Equipment are likely to exceed these design loads the deck and supporting structure shall be strengthened accordingly.


(2) The design of the temporary decks and support systems shall allow for environmental loads, including temperature difference.

(3) Temporary pedestrian overbridges together with supporting structures shall be

designed for a characteristic load of 5.0 kN/m2. (4) Permissible stresses shall comply with the relevant British Standard and the Building

(Construction) Regulations (Cap. 123) where appropriate. An overstress of 25% shall be allowed when checking the design of temporary road decks using HB loads only.

(5) All other types of temporary decks shall be designed using loading criteria reviewed

without objection by the Project Manager. A2.1.10 Falsework

(1) The design shall demonstrate that it includes full allowance for all dead, environmental (wind and temperature, as appropriate), and applied loads. The latter shall include an allowance for vertical loading on all parts of the falsework, for access and working conditions, which shall not be less than 1.5 kN/m2. Where heavy items of Contractor's Equipment are used or materials stored on the falsework or on the completed structure before it becomes self-supporting, this allowance shall be increased. The drawings shall be clearly marked with the maximum safe limit for loading of the falsework from items of Contractor's Equipment or materials.

(2) The falsework shall be designed to sustain the following horizontal loading, which

may act transversely or longitudinally, separately or simultaneously.

(a) Dynamic pressure head due to a wind speed in accordance with the recommendations stated in the "Code of Practice on Wind Effects, Hong Kong".

(b) Horizontal loads arising from the unintentional non-verticality of vertical load

carrying members. (c) Horizontal forces derived from impulse and impacts upon or attachments to the

falsework, unbalanced horizontal forces derived from the application of vertical loads to non-vertical surfaces, movements of the falsework due to temperature, creep, shrinkage, settlement, post-tensioning operations, external ties and anchorages.

(3) (a) The design of the Temporary Works shall ensure that the falsework receives the

loads from, and maintains in the required position, elements of the Permanent Works until they become self supporting. Facilities shall be provided for compensating for falsework deflections, the order of magnitude of which shall be calculated by the Contractor and reviewed without objection by the Project Manager.

(b) Loads imposed on the permanent structure by the falsework shall be within the

allowable load capacity of the permanent structure. Sufficient load spreading elements shall be used to achieve this as necessary. The design of the falsework shall include calculations to prove that the permanent structure is not overloaded.


(4) Falsework erected in close proximity to traffic or construction vehicles shall be protected against impact from vehicles by crash barriers. These shall be capable of sustaining a load of a 1.5 tonne vehicle striking the barrier at 110km/hour and at an

angle of 20° without permitting the vehicle or barriers to come into contact with any part of the falsework.

(5) Foundations for falsework shall be designed to sustain the calculated maximum loads

without failure or unacceptable settlement. The calculations shall by reference to soil data or tests demonstrate the validity of assumptions made in respect of permissible settlements and earth pressures under falsework foundations.

(6) All materials used as load carrying elements in the falsework shall conform to the

relevant British Standards and the Building (Construction) Regulations (Cap. 123) where appropriate in respect of quality, and the design shall use the basic permissible stresses in those standards. Materials not conforming with the relevant British Standard may be used, but only if the yield stress can be established. In which case the basic permissible stress shall be calculated by applying the same safety factor on that yield stress as used in the relevant British Standard.

(7) A minimum factor of safety of 1.2 is required against instability of the falsework

under any combination of vertical and horizontal load. (8) Testing of materials or components shall be carried out when their quality or

adequacy is in doubt. As far as possible, such tests shall conform to the appropriate British Standards or shall be as stated in the Contract.

(9) Where materials are re-used, the basic permissible stresses shall be reduced to suit the

condition of the material. A2.1.11 Formwork Formwork shall be designed by the Contractor to withstand the worst combination of the

following without causing bulging or deflection: (1) total weight of reinforcement, live concrete and formwork; (2) construction loading including the dynamic effects of placing and compacting

concrete and construction traffic; and (3) wind loads. A2.1.12 Earthworks Notwithstanding the requirements of Section 7, the design of Temporary Works associated

with earthworks, including temporary slopes, stockpiles and drainage, shall not prejudice the long term integrity or stability of the Permanent Works or present a risk to persons, property, the surface or groundwater conditions.


APPENDIX A2.2

CERTIFICATION OF THE DESIGN OF TEMPORARY WORKS DESIGN OF TEMPORARY WORKS Part 1 : To be signed by the Temporary Works Co-ordinator. Description of Temporary Works (full description including drawing references, if any): I certify that the Temporary Works described above have been designed in accordance with the Contract and that the design and drawings have been checked and found satisfactory by the undersigned. Date Signed Name [of Temporary Works Co-ordinator] For and on behalf of [Contractor's name] Part 2 : To be signed by the Checking Engineer. I certify that the Temporary Works described above have been designed in accordance with the Contract and that I have checked the design and drawings and found them satisfactory. Date Signed Print name of Checking Engineer, qualifications, and name of any company he represents.


APPENDIX A2.3

CERTIFICATION OF LOADING, DISMANTLING OR REMOVAL OF TEMPORARY WORKS

A2.3.1 Loading / Dismantling / Removal * of Temporary Work Part 1 : To be signed by the Temporary Works Co-ordinator. Description of Temporary Works (full description including drawing references, if any): a) I certify that the Temporary Works described above have been constructed in accordance with

the Contractor's Drawings and that they have been checked and found satisfactory for loading by the undersigned.

b) I certify that any structure supported by the falsework described above has been checked by

the undersigned and that it has become self supporting and that the Temporary Works may be dismantled or removed.

[a)/*b)] Date Signed Name [of Temporary Works Co-ordinator] For and on behalf of [Contractor's name] Part 2 : To be signed by the Checking Engineer. a) I certify that the Temporary Works described above have been constructed in accordance with

the Contractor's Drawings and that they have been checked and found satisfactory for loading. b) I certify that any structure supported by the Temporary Works described above has become

self supporting and that the Temporary Works may be dismantled or removed. [a)/*b)] Date Signed Print name of Checking Engineer, qualifications, and name of any company he represents * Use only one of the alternatives, as appropriate.


SECTION 3 SITE CLEARANCE AND DEMOLITION

3.1 GENERAL 3.1.1 General Requirements

The works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section.

(a) The abandonment of pipes and manholes shall comply with Section 6. (b) Earthworks, shall comply with Section 7.

3.1.2 Methods of Demolition

Use of the following demolition methods will not be permitted;

(a) ‘wrecking ball’; (b) ‘drop ball’; and (c) ‘blasting’.

3.2 RELEVANT CODES AND STANDARDS 3.2.1 Applicable Regulations and Codes

All demolition works shall be carried out in accordance with Building (Demolition Works) Regulations, Code of Practice for Demolition of Buildings, Technical Memorandum for Supervision Plans and Code of Practice for Site Safety Supervision issued by the Buildings Department; approved demolition plans by the Buildings Department, Practice Note for Authorized Persons and Registered Structural Engineers (PNAP) No. 71, all other relevant PNAP and all relevant requirements issued by the HK Government and/or Statutory Authorities.

3.2.2 Employment of Registered Structural Engineer

The Contractor shall appoint a Registered Structural Engineer registered under the Buildings Ordinance for the preparation of demolition method statement, supervision and control of demolition works, scaffolding, shoring and strutting etc.

3.3 SUBMISSIONS 3.3.1 Survey

Areas to be cleared and any structures to be demolished shall be surveyed by the Contractor, and the results submitted to the Project Manager for information, no less than 7 days before demolition starts.


3.3.2 Registered Demolition Contractor and Supervisor

Particulars of the Registered Demolition Contractor, and the Supervisor employed on the demolition works shall be submitted to the Project Manager for review.

3.3.3 Particulars of Operators of Powered Mechanical Plant or Equipment

The personnel particulars, qualifications and experience of the operators of any powered mechanical plant or equipment proposed to be used in demolition works shall be submitted to the Project Manger for review without objection, in a form suitable for onward submission to the Buildings Department for application for consent to commence demolition works.

3.3.4 Particulars of Method of Demolition

Before commencement of demolition works the Contractor shall submit to the Project Manager for review without objection a method statement indicating the following:

(a) proposed method of demolition of each type of structural elements;

(b) sequence of demolition;

(c) method of transporting debris from the upper floors to ground level;

(d) method of raising mobile plant to the roof or upper floors and movement between

floors;

(e) the weight and size of plants used above ground. The support to the floors and other restrictions must be illustrated;

(f) design calculations and drawings showing the maximum debris loadings for all areas and combinations thereof, layout of all necessary falsework or temporary works required for all stages of the works; and

(g) location of all chutes for conveying debris down the building floors, and offsite. 3.3.5 Demolition Waste

A Waste Management Plan shall be prepared in accordance with PNAP 243 and submitted to the Project Manager for review.

3.3.6 Sorting and Disposal of Materials

A method statement for the sorting, processing and disposal of materials arising from or in connection the demolition work shall be prepared in accordance with PNAP 243 and Section 7 of the General Specification and submitted to the Project Manager for review without objection before the commencement of any demolition works.

3.3.7 Site Safety Supervision Plan

The Contractor shall submit to the Project Manager for review without objection, the Site Safety Supervision Plan, prepared in accordance with the Technical Memorandum for Supervision Plan and Code of Practice for Site Safety Supervision of Building Works and Street Works.


3.4 WORKMANSHIP 3.4.1 Existing Services

Before commencement of demolition works the Contractor shall:

(a) locate and identify the position of existing services and utilities affected by the works; and

(b) arrange with the relevant Authorities for the disconnections or diversion of all services and utilities and the removal of all associated fittings and equipment.

3.4.2 Trees

(a) The roots of trees and shrubs which have been cut down shall be grubbed up. Branches shall not be removed from trees which are to be retained unless permitted by the Project Manager; if permitted, the branches shall be removed in accordance with BS 3998 and the cut surfaces shall be treated with a wound sealant.

(b) In respect of existing trees and woodland the Contractor shall ensure for the duration

of the Contract, the following:

(i) there is no unnecessary intrusion into areas of woodland or scrubland;

(ii) the limits of site clearance shall be reviewed without objection by the Project Manager on Site before site clearance commences. All trees to be cleared shall be marked by the Contractor and reviewed without objection by the Project Manager before felling;

(iii) trees not required to be trimmed, pruned or felled shall not be marked;

(iv) nails or other fixings shall not be driven into trees;

(v) fencing or signs shall not be attached or painted on trees;

(vi) trees shall not be used as anchors for ropes or chains used in guying, pulling

and the like; and

(vii) fires shall not be lit under or in the close proximity of trees.

(c) As soon as the Site or any part thereof becomes available the Contractor shall erect temporary protective fencing reviewed without objection by the Project Manager around any tree and group of trees which are required to be protected. The fence shall not be closer than 2 m from the trunk of any such tree and all such work shall be executed using only hand-held tools.

3.4.3 Stripping Topsoil

At the commencement of any excavation and prior to any filling the Contractor shall strip any humus topsoil capable of being used as soil conditioner and set it aside for subsequent use in the Works. Any topsoil surplus to the requirement of the Works shall be disposed of in accordance with Clause 7.5.9. Temporary stockpiles of topsoil shall not exceed 2 m in height.


3.4.4 Precautionary Measures

Demolition works shall not commence until all the required precautionary measures have been installed in accordance with Building (Demolition Works) Regulations, Code of Practice for Demolition Works, Technical Memorandum for Supervision Plans and Code of Practice for Site Safety Supervision issued by the Buildings Department; approved demolition plans by the Buildings Department, PNAP 71, all other relevant PNAP and all other relevant requirements issued by the HK Government and/or Statutory Authorities.

3.4.5 Prevention of Overloading

The Contractor shall;

(a) not overload the structure under demolition with demolition plant and/or resulting debris;

(b) comply with the propping requirements or temporary propping system during the operation of mechanical plant on suspension floor as stipulated in the Code of Practice for Demolition of Buildings;

(c) provide all temporary shoring, strutting and/or propping required;

(d) secure and wedge tight top and bottom supports to props. The props shall be braced to provide lateral restraints in at least 2 directions;

(e) not allow mobile equipment to move to within 2 m of the building edge, 1 m of any floor opening or on to any cantilevered structures; and

(f) provide adequate spreaders for props bearing on ground, where necessary, to avoid any undue settlement;

3.4.6 Warning Signs

The Contractor shall erect warning signs in prominent positions indicating demolition works are in progress in both Chinese and English.

3.4.7 Overhead Wires

The Contractor shall prevent damage to overhead wires during demolition operations.

3.4.8 Risk of Fire Explosion

The Contractor shall take precautions to prevent fire or explosion from gas or vapour release, electricity or any other source, especially when removing tanks or pipes which may have contained flammable liquids or gases.

3.4.9 Weatherproofing Retained Areas of Partially Demolished Buildings

(a) Where partially demolished buildings or structures are to be retained the Contractor

shall protect the retained building structure and interiors exposed during the course of demolition works with a temporary weather-tight screen erected 1000 mm back from the perimeter edge of floors.


(b) Screens shall be constructed with close boarding fixed to framing and faced outside with roofing felt of a type reviewed without objection. The exposed floor beyond the screening shall be covered with roofing felt of similar type to that used to face screens and a waterproof seal formed between floor and screen. Doors in the screens shall be constructed and fixed with secure fastenings and hanging devices as necessary to provide authorised access.

3.4.10 Partly Demolished Structures

The Contractor shall leave the Site and partly demolished structures in a safe condition at the end of each day’s work. No accumulation of debris shall be allowed, particularly at working floors and at ground floor, which causes excessive pressure on the floors, slopes, retaining structures, hoardings/covered walkways, catchfans and walls of adjoining structures.

3.4.11 Care of Electric Cables

The Contractor shall take every precaution to prevent damage and to exercise extreme care during execution of the work in the vicinity of live electrical cables.

3.4.12 Disused Drains

The Contractor shall disconnect and seal off all storm water drains or sewers from the last manhole to the Government storm water drain or sewer in accordance with the requirements of the Relevant Authorities.

3.4.13 Burning

The Contractor shall not burn any rubbish or materials arising from the demolition on Site.

3.4.14 Spoil Heaps

(a) The Contractor shall prevent excessive lateral pressure due to stockpiling of debris against walls, adjoining structures and steel hoardings adjoining the public footpaths or carriageways.

(b) Spoil heaps shall be not be placed on catch platforms or on top of covered walkways.

Spoil heaps shall be cleared away immediately to prevent overloading any part of the existing structure.

3.4.15 Reinstatement

(a) Areas affected by Site clearance shall be reinstated as follows:

(i) Fine fill material shall be deposited and compacted in voids which are left in

the ground.

(ii) Holes which are left in structures and pavements shall be made good using material similar to the material in the adjoining area.

(iii) The ends of fences, walls, structures, utilities and other items shall be made

good in such a manner that the affected parts will not corrode or deteriorate, and will remain stable.

(iv) Straining posts shall be fixed at the end of strained fences which have been cut

and the fences shall be restrained.


3.4.16 Materials and Equipment for Re-use and Storage

(a) Items to be re-used or taken to store shall be dismantled and removed by a suitable method so as to avoid or minimise damage. The items shall be cleaned before taking to store.

(b) Items to be re-used in the Works shall be kept in stores provided by the Contractor. (c) Items which are to be taken to the Employer's store shall be delivered by the

Contractor. (d) Materials or equipment which are to be reused or taken to store and which are

damaged due to the Contractor’s negligence shall be repaired by the Contractor by a method reviewed without objection by the Project Manager. Materials or equipment which are lost or which are not capable of being repaired satisfactorily shall be replaced by the Contractor. Except for items which are to be re-used or taken to store, demolished items, trees, shrubs, vegetation, boulders, debris, rubbish and other items arising from site clearance shall be disposed of by the Contractor and shall become the property of the Contractor when they are removed from the Site.

(e) All construction and demolition materials arising from or in connection with the

demolition work shall be sorted on-Site and separated into different groups for disposal at landfills, public filling areas, in filling areas provided by the Contractor, or recycling as appropriate.

(f) Unless otherwise stated in the Contract, all construction and demolition materials

arising from or in connection the demolition work shall become the property of the Contractor. The Contractor shall promptly remove all sorted and processed materials arising from or in connection with the demolition work from the Site on a regular basis as demolition work proceeds.

3.4.17 Remove debris

(a) All construction and demolition materials arising from or in connection with the

demolition work shall be sorted on-Site and separated into different groups for disposal at landfills, public filling areas, in filling areas provided by the Contractor, or recycling as appropriate.

(b) Unless otherwise stated in the Contract, all construction and demolition materials

arising from or in connection the demolition work shall become the property of the Contractor. The Contractor shall promptly remove all sorted and processed materials arising from or in connection with the demolition work from the Site on a regular basis as demolition work proceeds.

3.5 INSPECTION 3.5.1 Joint Inspections

Prior to the commencement of site clearance and demolition, and after completion, the Contractor shall undertake joint inspections with the Project Manager of all existing structures to be retained within the Site and produce a Condition Survey Report submitted to the Project Manager for review. Any damage noted to the structures during the second inspection shall be made good by the Contractor to the satisfaction of the Project Manager. Photographic records, taken by the Contractor and reviewed without objection by the Project Manager, shall be kept as part of the joint inspection.


SECTION 4 LANDSCAPE SOFTWORKS AND ESTABLISHMENT WORKS 4.1 GENERAL 4.1.1 General Requirements


(a) Site clearance shall comply with Section 3.

(b) Earthworks shall comply with Section 7.

(c) Landscape hardworks shall comply with Section 11.

(d) Geotechnical works shall comply with Section 8.

4.1.2 Weather and Ground Conditions

Soiling, cultivation, planting and other similar landscape softworks and establishment works operations shall not be carried out at times when weather or ground conditions may adversely affect the Permanent Works.

4.1.3 Use of Chemicals

Chemicals shall not be used for landscape softworks and establishment works except with the permission of the Project Manager. Chemicals shall be used, stored, mixed and applied in accordance with the manufacturer's recommendations. Containers for chemicals shall be disposed of off-Site by methods reviewed without objection by the Project Manager.

4.2 DEFINITIONS AND ABBREVIATIONS 4.2.1 Landscape Softworks

Landscape softworks are all works of a horticultural nature, and shall include the placing, cultivation and preparation of topsoil and subsoil layers, and the supply and planting of trees, shrubs and other plant material, and any associated works.

4.2.2 Landscape Hardworks

Landscape hardworks shall include the paving, tree grilles, tree guards and tree rings and any other items stated as such in the Contract.

4.2.3 Establishment and Landscape Works

(a) Establishment works shall include the regular inspections, cultivation, watering, fertilizing and other operations specified to be performed during the period stated in the Contract for such inspections and operations.

(b) Landscape works means landscape softworks, landscape handworks and

establishment works.


4.3 RELEVANT CODES AND STANDARDS 4.3.1 British Standards Relevant to Landscape Softworks and Establishment Works

A list of British Standards publications relevant to landscape softworks and establishment works is included as Appendix A4.1. Works shall comply with these standards.

4.4 MATERIALS 4.4.1 Seedling Trees

Seedling trees shall have the following characteristics:

(a) less than 2 years old; (b) single slender stem; (c) well developed vigorous root system; (d) height above soil level of between 150 mm and 900 mm; and (e) grown in a container at least 50 mm diameter and 150 mm deep.

4.4.2 Whip Trees

Whip trees shall have the following characteristics:

(a) less than 3 years old; (b) single central stem well furnished with side branches according to species; (c) well developed vigorous root system; (d) height above soil level of between 900 mm and 2000 mm; and (e) grown in a container at least 75 mm diameter and 150 mm deep.

4.4.3 Light Standard Trees

Light standard trees shall have the following characteristics: (a) sturdy straight stem at least 1500 mm high from soil level to the lowest branch; (b) stem diameter of between 20 mm and 25 mm measured at a height of 1 m from soil

level; (c) according to species, either a well balanced branching head or a well defined straight

and upright leader with branches growing out from the stem with reasonable symmetry;

(d) total height above soil level of between 2000 mm and 3000 mm; and (e) rootball at least 300 mm diameter and 250 mm deep.


4.4.4 Standard Trees

Standard trees shall have the following characteristics :

(a) sturdy straight stem at least 1800 mm high from soil level to the lowest branch; (b) stem diameter of between 25 mm and 50 mm measured at a height of 1 m from soil

level; (c) according to species, either a well balanced branching head or a well defined straight

and upright leader with branches growing out from the stem with reasonable symmetry;

(d) total height above soil level of between 2750 mm and 3500 mm; and (e) rootball at least 350 mm diameter and 300 mm deep.

4.4.5 Heavy Standard Trees

Heavy standard trees shall have the following characteristics :

(a) sturdy, straight stem at least 2100 mm high between the soil level and the lowest branch;

(b) stem diameter of between 50 mm and 100 mm measured at a height of 1 m from soil

level;

(c) according to species, either a well balanced branching head or a well defined straight and upright leader with branches growing out from the stem with reasonable symmetry;

(d) total height above soil level exceeding 3500 mm; and

(e) rootball at least 400 mm diameter and 350 mm deep.

4.4.6 Small Shrubs

Small shrubs shall have the following characteristics :

(a) at least two one-year old vigorous stems arising at or near the base;

(b) well developed, vigorous root system;

(c) according to species, height above soil level not less than the height stated in the Contract; and

(d) grown and supplied in a container at least 75 mm diameter and 125 mm deep.

4.4.7 Large Shrubs

Large shrubs shall have the following characteristics :

(a) bush with at least three one-year old vigorous stems arising at or near the base, with an overall diameter equal to 2/3 of the height;

(b) well developed vigorous root system;


(c) according to species height above soil level not less than the height stated in the

Contract; and

(d) grown and supplied in a container at least 100 mm diameter and 125 mm deep. 4.4.8 Conifers

Conifers shall have the following characteristics :

(a) well developed stem well furnished with leaf or needle bearing side shoots;


(c) size not less than that stated in the Contract; and

(d) grown and supplied in a container with dimensions not less than the dimensions stated in the Contract.

4.4.9 Palms

Palms shall have the following characteristics:

(a) well developed upright habit with a well balanced, symmetrical head;


(c) for single stem species, height above soil level to the growth point not less than the height stated in the Contract;

(d) for multi-stemmed species, height above soil level to the growth point not less than

the overall height stated in the Contract; and

(e) rootball or grown and supplied in a container at least 300 mm diameter and 300 mm deep.

4.4.10 Bamboo

Bamboo shall have the following characteristics :

(a) well developed vigorous root system;

(b) for single stem species, a single shoot or trunk with height above soil level not less than the height stated in the Contract;

(c) for multi-stemmed species, a clump of at least three stems with height above soil level

not less than the height stated in the Contract; and

(d) rootball or grown and supplied in a container at least 200 mm diameter and 200 mm deep.


4.4.11 Herbaceous Plants

Herbaceous plants shall have the following characteristics : (a) well developed vigorous shoots; (b) a well developed vigorous root system; (c) height above soil level or diameter of plant for clumps not less than the height or

diameter stated in the Contract; and (d) healthy well developed bulbs, corms, rhizomes or tubers.

4.4.12 Containerised Plants

Containerised plants shall be grown in open ground and then lifted and placed in a rigid or semi-rigid container. Plants shall be left to grow in the containers for at least 3 months before being delivered to Site. The dimensions of containers shall not be less than the relevant rootball or container dimensions stated in Clauses 4.4.1 to 4.4.10.

4.4.13 Grass Seed

(a) Grass seed shall be supplied true to species and variety and shall not contain impurities except as stated in Clause 4.6.13(b). Containers shall be labeled with the origin of all seed contained therein and the name of the supplier.

(b) The quality of grass seed shall be gauged by purity, germination percentage and

freedom from weeds. The total weed seed content shall not exceed 0.5% by mass and the total content of other crop seeds shall not exceed 1% by mass.

4.4.14 Turf

(a) First quality turf shall consist of 75%-85% axonopus compressus and 15%-25% cynodon dactylon and other stoloniferous species unless otherwise stated in the Contract.

(b) The grass shall be of even density, forming a turf which is sufficiently fibrous to hold

together when handled. The grass shall be free from pest or disease. Turf shall consist of sods with soil and roots.

4.4.15 Sprigs

Sprigs shall consist of axonopus compressus, cynodon dactylon, paspalum distichum and other stoloniferous grasses. Axonopus compressus shall not be used on slopes exceeding 15 to the horizontal. Sprigs shall be at least 100 mm long.

4.4.16 Soil-mix

Soil-mix shall consist of friable, completely decomposed granite and soil conditioner in the proportions 3 : 1 by volume. Soil-mix shall be free from grass or weed growth, sticky clays, salt, stones exceeding 50 mm diameter, the materials stated in Clause 7.2.1(b) and other deleterious material.


4.4.17 Soil Conditioner

(a) Soil conditioner shall be organic material and shall be free from impurities and substances injurious to plants. Soil conditioner shall have the following properties :

(i) the pH value shall be between 5.0 and 7.5; (ii) the moisture content measured in accordance with Clause 7.5.11(b) shall be

between 30% and 50%; (iii) the consistency shall be fine and freely flowing; and (iv) the carbon/nitrogen ratio shall be between 25 and 70.

(b) Soil conditioner shall be peat moss or properly composted organic material.

Composted organic material shall be stable and shall not be liable to decompose further generating heat.

4.4.18 Mulch

Mulch shall be a composted organic material either as stated in Clause 4.4.17 for soil conditioner or granulated tree bark or wood shavings. The properties of mulch shall be as stated in Clause 4.4.17 for soil conditioner except that the consistency shall be coarser to avoid being blown away by wind.

4.4.19 Mulch for Hydroseeding

Mulch for hydroseeding shall be a proprietary type manufactured from cellulose or paper based materials and reviewed without objection by the Project Manager.

4.4.20 Fertilizer

(a) Pre-planting fertilizer shall be provided in the ratio of 15:9:15:2 (nitrogen / phosphorus / potassium / magnesium) slow release granular fertilizer.

(b) Post-planting fertilizer shall be 12:12:17 (nitrogen/phosphorus/potassium) granular

fertilizer.

(c) Hydroseeding fertilizer shall be 15:15:15 (nitrogen/phosphorus/potassium).

(d) Phosphate fertilizer shall be triple superphosphate powder.

(e) Fertilizer shall be supplied in sealed waterproof bags.

4.4.21 Soil Binder

Soil binder shall be a proprietary type reviewed without objection by the Project Manager and shall consist of a binding medium applied in aqueous suspension by spraying onto the surface of the soil to stabilise and condition the soil. The binding agent shall not be injurious to plant growth.

4.4.22 Stakes, Ties and Guys

(a) Steel stakes for heavy standard trees shall be 25 mm x 25 mm x 4 mm or 40 mm x 40 mm x 4 mm angle iron and shall have the appropriate lengths stated in Clauses 4.6.3(d), 4.6.3(h)(ii) and 4.6.3(i)(ii); steel stakes shall have all sharp edges removed to avoid damage to the tree.


(b) Ties shall be rot-proof rope or straps fitted with plastic, bamboo or other spacers and a protective sleeve to fit around the plant; ties shall be capable of adjustment after fixing.

(c) Guys shall be a multi-strand twisted galvanized steel wire of between 4 mm and 6 mm

diameter. Each guy shall be fitted with a flexible rubber or plastic sleeve to prevent chafing, rubbing or abrasion of the plant, and a turnbuckle for adjustment.

4.4.23 Protective Fabric Material

Protective fabric material for hydroseeding shall be a proprietary type of degradable fabric reviewed without objection by the Project Manager. The fabric shall not degrade within 100 days after application or until the specified grass cover has been established.

4.5 SUBMISSIONS 4.5.1 Particulars of Seed Mixture, Turf, Sprigs, Soil Conditioner and Water

(a) The following particulars of the proposed materials for landscape softworks and establishment works shall be submitted to the Project Manager for review:

(i) origin of trees, shrubs, turves, sprigs and other plant material; (ii) details of nurseries;

(iii) a certificate or a numbered seed analysis report for each seed mixture issued

within 6 months before the date of use of the seed showing the species and variety of the seed, the date of testing and including results of tests for; - percentage germination of pure seed in a fixed time under standard

laboratory conditions; and - percentage composition by weight, including details of impurities;

(iv) a certificate of analysis for soil conditioner including details of the composition

and results of tests for; - pH value; - moisture content; and - carbon/nitrogen ratio; and

(v) source of water for watering.

4.5.2 Particulars of Hydroseeding

(a) The following particulars of the proposed materials and methods for hydroseeding shall be submitted to the Project Manager for review:

(i) species and rate of application of grass seed; (ii) type and rate of application of fertilizer, mulch and soil binder; (iii) type and colour of dye; (iv) type of protective fabric material;

(v) details of the company employed to carry out the hydroseeding and the

equipment to be used; and


(vi) manufacturer and details of mulch for hydroseeding. 4.5.3 Representative Samples of Materials

(a) Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(i) each seed mixture;

(ii) turf;

(iii) sprigs; and

(iv) soil-mix.

(b) Representative samples of materials for landscape works and establishment works

shall be made available for inspection by the Project Manager, at nurseries and other sources before the materials are delivered to the Site.

(c) A certificate of purity of the grass seed to be used in the Works shall be submitted to

the Project Manager. The batch number of the certificate shall be checked against that on the bag. The certificate shall not be more than 6 months operations, a 500 g seed sample shall be supplied and retained under refrigeration by the Project Manager until the viability of the seed is proven or disproven on Site. Impurities in the seed mix such as stores, soil, twigs and other foreign matter shall not be accepted.

(d) Before any turf is delivered to the Site, the Contractor shall provide a sample of at

least 4 m2 from the source for review without objection by the Project Manager. 4.6 WORKMANSHIP 4.6.1 Handling, Storage and Transport

(a) Handling and storage of rootballed stock:

Plants grown in open ground shall be well watered before lifting and shall be lifted in such a manner that the specified rootball is obtained with minimum disturbance to the roots. The rootball shall be securely wrapped immediately after lifting to prevent loss of soil and moisture using hessian or straw. The wrapping material shall not be removed until the plant is required for planting.

(b) Handling and storage of container grown and containerised stock:

Container grown and containerised stock shall be well watered before despatch from the nursery and shall remain in the containers until required for planting.

(c) Transport of plants:

Plants shall be wrapped and protected to prevent mechanical damage during lifting and transportation. The trunk from soil level to the lower branches of trees in the light standard, standard and heavy standard categories shall be securely wrapped to prevent moisture loss using hessian or straw. All plants which are to be removed while in leaf shall be covered with tarpaulins during transport to reduce excessive transpiration.


(d) Storage of plants:

(i) Plants shall be protected from exposure to conditions which may affect the plant adversely.

(ii) Plants shall be protected from damage and damaged plants shall not be used in

the Permanent Works unless permitted by the Project Manager. If the Project Manager permits damaged plants to be used, damaged material shall be pruned and wounds shall be dressed as stated in Clause 4.6.5(g).

(e) Storage of trees and shrubs:

Trees and shrubs which are not immediately planted in their permanent positions shall be supported upright on level ground, regularly watered and maintained in good condition.

(f) Handling and storage of turf and sprigs:

Turf and sprigs shall not be lifted when waterlogged or very dry and shall be packed to avoid drying out. Turf and sprigs shall be stored by spreading out and shall not be stacked. Turf and sprigs shall be kept moist and in good condition and shall be delivered and laid within 72 hours of lifting.

(g) Storage of grass seed:

Grass seed shall be stored in bags off the ground in a clean, dry, well ventilated location free from vermin. Prolonged storage shall be carried out under controlled conditions of temperature and humidity.

(h) Storage of fertilizer:

Fertilizer shall be stored off the ground in sealed waterproof bags and shall be protected from exposure to conditions which may adversely affect the fertilizer.

4.6.2 Pre-planting Works

(a) Preparatory works:

Before soiling or planting for landscape softworks and establishment works starts, preparatory works shall be carried out by one or more of the treatments stated in Clauses 4.6.2(b) to 4.6.2(i), as appropriate or as stated elsewhere in the Contract.

(b) Cleaning ground:

Weeds, rubbish, litter, stones exceeding 50 mm diameter and all deleterious material shall be removed from the surface of the ground. Vegetation shall be cleared without using herbicide unless permitted by the Project Manager. If permitted, the herbicide shall be a proprietary type reviewed without objection by the Project Manager and shall be applied in accordance with the manufacturer's recommendations.

(c) Ripping:

The ground shall be ripped by drawing a tine through the soil to a depth of 300 mm at 500 mm centres. All obstructions to cultivation or deleterious material brought to the surface shall be removed and voids left by the ripping operation shall be filled with soil of the same type as existing. Ground at a slope exceeding 15 to the horizontal shall not be ripped.


(d) Contaminated ground:

Ground which is contaminated by oil, chemicals or other substances which may affect plant growth adversely shall be excavated to 300 mm below the contaminated depth and beyond the extent of the contamination. Voids left by excavation shall be filled with uncontaminated soil of the same type as existing.

(e) Soiling:

Soil-mix shall be spread and levelled to the depth stated in the Contract. The depth of uncompacted soil-mix shall be sufficient to allow the level of the area to comply with finished levels after natural settlement has taken place. The finished level of soil-mix over areas to be grassed shall be 25 mm above adjacent kerbs, paving, covers, frames and other hardware.

(f) Cultivation:

(i) Cultivation shall be carried out to a minimum depth of 150 mm or as stated in

the Contract. Pre-planting fertilizer and soil conditioner shall be spread to a thickness of 50 mm over the surface before cultivation.

(ii) Stones exceeding 50 mm diameter shall be removed from the surface of the soil

after cultivation.

(g) Scarifying:

Scarifying shall be carried out by loosening the soil to a depth of between 10 mm and 20 mm using a pronged implement such as a rake but without turning the soil.

(h) Protection of prepared ground:

(i) Prepared ground shall be protected from compaction, erosion and siltation and

shall not be used by Contractor's Equipment, other vehicles or pedestrian traffic.

(ii) Prepared ground which becomes compacted, eroded, silted up or damaged shall

be replaced or dealt with by methods reviewed without objection by the Project Manager.

(i) Removal of material:

Weeds, rubbish, litter, stones exceeding 50 mm diameter and deleterious material removed during ground preparation shall be disposed of by the Contractor by methods reviewed without objection by the Project Manager.

4.6.3 Planting

(a) General:

Planting shall be carried out between 1st March and 30th September unless otherwise specified in the Contract.


(b) Use of excavated material:

Material excavated from planting pits which complies with the specified requirements for decomposed granite shall be used for soil-mix. Material excavated from planting pits which does not comply with the specified requirements for decomposed granite shall be disposed of by the Contractor and shall be replaced by material which complies with the specified requirements for decomposed granite.

(c) Planting:

(i) Plants shall be well watered several hours before planting; the soil in the

container or rootball shall be moist and cohesive. Containers or rootball wrapping shall not be removed until the time of planting and the rootball shall not be disturbed by loosening or breaking.

(ii) Each plant shall be placed upright in the pit and set at the same level as planted

in the nursery or container.

(iii) Soil-mix shall be deposited and compacted in layers around the rootball until level with the surrounding ground in such manner that the rootball is not disturbed. Plant shall be well watered to soak the rootball and soil-mix immediately after planting.

(d) Staking, tying and guying:

(i) Stakes shall be driven into the ground after the pit has been excavated and

before planting in such a manner that the rootball and aerial parts of the plant are not damaged. The stake shall be secure after driving and shall be higher than 70% of the overall height of the plant.

(ii) Guys and sleeves shall be fixed to prevent chafing, rubbing and abrasion of the

plant and shall be secured to a well driven steel stake or other anchor. Each plant shall be fitted with three guys secured at a point not higher than 60% of the overall height of the plant. Turnbuckles shall be adjusted as necessary after planting.

(iii) Bamboo stakes shall be used in locations stated in the Contract. Bamboo stakes

shall be securely tied with "scaffold tie" to form a tripod not exceeding 60% of the overall height of the plant.

(e) Mulching:

After planting and watering, mulch shall be spread to a consolidated thickness of at least 50 mm on areas of bare ground as stated in the Contract.

(f) Notch planting of seedlings:

Notch planting of seedlings shall be carried out by forming a notch making two cuts at approximately 90 using a hand held pick or spade with the apex pointing up any slope; the notch shall be sufficiently deep to accommodate the root system of the seedling. The notch shall be opened on the second cut to receive the plant and shall then be pushed firmly back into place.


(g) Pit planting of seedlings, shrubs, whips and herbaceous plants:

(i) The size of pits for seedlings, shrubs, whips and herbaceous plants shall be 100 mm greater than the rootball or container diameter and 50 mm deeper than the rootball or container. 50g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Whips which require staking shall be secured using one 2 m long stake and one

tie.

(h) Pit planting of light standard and standard trees:

(i) The size of pits for light standard trees and standard trees shall be 200 mm greater than the rootball or container diameter and 100 mm deeper than the rootball or container. The bottom of the pit shall be broken up to a depth of 150 mm. 150 g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Each tree shall be secured using two 2.5 m long steel stakes and two ties.

(i) Pit planting of heavy standard trees:

(i) The size of pits for heavy standard trees shall be 300 mm greater than the

rootball or container diameter and 150 mm deeper than the rootball or container. The bottom of the pit shall be broken up to a depth of 150 mm. 250 g of pre-planting fertilizer shall be mixed into the soil-mix.

(ii) Each tree shall be secured using two 3 m long steel stakes and two ties. Trees

exceeding 4 m overall height shall be guyed.

(j) Pit planting of bamboos and palms:

Bamboos and palms shall be planted in accordance with the following :

(i) height not exceeding 2000 mm : Clause 4.6.3(g)

(ii) height exceeding 2000 mm and not exceeding 2500 mm : Clause 4.6.3(h)

(iii) height exceeding 2500 mm : Clause 4.6.3(i)

(k) Pit planting on slopes:

Pits excavated for planting on or adjacent to slopes shall not be left open during wet weather.

4.6.4 GRASSING

(a) Hydroseeding:

Hydroseeding shall be carried out between 1st March and 30th September unless otherwise specified in the Contract.


(b) Hydroseeding cover:

Hydroseeding shall achieve a cover by grass species of at least 90% of the surface area of each 10 m² of the area to be hydroseeded within 100 days after the area has been hydroseeded. The grass cover shall be healthy, vigorous and free from perennials and other weeds. The method of determining the cover shall be as stated in Clauses 4.7.1(a) to 4.7.1(g).

(c) Surface conditions for hydroseeding:

The surface to be hydroseeded shall be finished to a coarse open textured surface and shall not be smooth or glazed. Finishing work on slopes by machines shall be carried out across the slope. Vehicle track marks and bucket teeth marks shall not be left parallel to the line of maximum gradient of the slope.

(d) Application of hydroseeding:

(i) Hydroseeding shall be carried out using a proprietary type of hydroseeding

equipment reviewed without objection by the Project Manager.

(ii) Materials for hydroseeding shall be well mixed on the Site in the hydroseeding equipment immediately before spraying. Seed shall not be damaged from the hydroseeding process.

(iii) Soil binders shall be applied at the rate recommended by the manufacturer,

modified as necessary to suit conditions in Hong Kong. Dye shall be used to demonstrate that adequate cover has been achieved, unless in the opinion of the Project Manager runoff or water courses will be coloured to an unacceptable level.

(iv) The hydroseeding mixture shall be constantly agitated during spraying to keep

it homogeneous and avoid blockage to pipes. Measures shall be taken during application to ensure that material is not lost due to runoff.

(v) Walking on areas that have been hydroseeded shall be restricted to access for

fixing protective material and for patching up.

(e) Protective material:

Areas which have been hydroseeded shall be covered with protective material within 2 days after hydroseeding. The material shall be spiked or stapled to the soil surface with a minimum of 150 mm overlap.

(f) Patching up:

(i) Immediately after germination and a general greening of the hydroseeded area

is apparent, areas where germination has been unsuccessful shall be resprayed. Areas affected by repairs to washout and gullies and other erosion on slopes shall be resprayed.

(ii) Areas which in the opinion of the Project Manager are not accessible or are too

small for the use of a hydroseeder shall be patched up by broadcasting seed. The area shall be lightly scarified with a rake or similar implement and the seed and fertilizer shall be broadcast over the area at a rate of not less than 75 g/m². The seed shall be covered by lightly working into the surface or by spreading sufficient soil to just cover the seed. Broadcast seeding shall be carried out using Bermuda grass (cynodon dactylon) perennial ryegrass (lolium perenne) or carpet grass (axonopus compressus).


(g) Post-planting fertilizer:

Post-planting fertilizer shall be applied between 2 months and 9 months after application of hydroseed and shall be applied between 1st March and 30th September.

(h) Turfing:

(i) Turf shall not be laid on slopes exceeding 15 to the horizontal.

(ii) The area to be turfed shall be cultivated by applying pre-planting fertilizer at a

uniform rate of 40 g/m² and shall then be raked and consolidated to the required level. The finished level after turfing shall be 25 mm above adjacent kerbs, paving, covers, frames and other hardware.

(iii) The turves shall be laid on the prepared soil and shall be firmed into position

using wooden beaters; the beaters shall be frequently scraped clean of accumulated soil or mud. A top dressing of soil-mix shall be applied and well worked into joints and spaces. Irregularities in finished levels due to variation in turf thickness or uneven consolidation of the soil shall be adjusted.

(iv) Turfed areas shall be watered immediately after turf has been laid and as often

as is necessary to ensure establishment. If shrinkage occurs and the joints open, soil-mix shall be worked in and well watered.

(i) Sprigging:

(i) Sprigging shall not be used on slopes exceeding 45 to the horizontal.

(ii) The area to be sprigged shall be scarified before sprigging and sprigs shall be

evenly spread over the area at approximately 50 mm centres. The area shall be topdressed with soil-mix to just cover the sprigs and pre-planting fertilizer shall

be applied at a uniform rate of 40 g/m².

(j) Completion of turfing and sprigging:

(i) Turfing and sprigging shall be considered to be complete when the first flush of growth achieves 90% cover. The method of determining the cover shall be as stated in Clauses 4.7.1(a) to 4.7.1(g).

(ii) Bare patches or areas which fail to become established shall be returfed or

resprigged to maintain 90% cover throughout the establishment period. Areas affected by repairs to washouts and gullies and other erosion shall be returfed or resprigged.

4.6.5 Establishment Works

(a) Establishment works:

(i) Establishment works shall be carried out for the period stated in the Contract.

(ii) All necessary measures shall be taken to ensure that grass, trees and other plants become established and to keep the landscape softworks neat and tidy and free from litter and rubbish.


(b) Replacement of plants and grass:

(i) Plant which are dead, dying or otherwise unsatisfactory shall be replaced. Replacement planting shall be carried out in season as stated in Clause 4.6.3(a)(ii) using plant material of a similar size to that already established. Measures shall be taken to ensure satisfactory establishment of the replacement plants before the end of the period for establishment works.

(ii) 90% cover of the grass area shall be maintained throughout the period for

establishment works and the grass shall provide effective cover of 90% of the area at the end of the period for establishment works. The grass shall be healthy, vigorous and free from perennials and other weeds. Areas which do not comply with this requirements of the Contract shall be reseeded by hydroseeding or broadcast seeding as stated in Clause 4.6.4(f)(ii) or returfed as stated in Clause 4.6.4(h) or sprigged as stated in Clause 4.6.4(i). Measures shall be taken to ensure satisfactory establishment of the replacement grass or turf before the end of the period for establishment works.

(c) Security of stakes and ties:

The Contractor shall be responsible for the security of stakes and ties throughout the establishment period. An inspection of stakes and ties shall be carried out each month by the Contractor; broken, damaged and other unsatisfactory stakes and ties shall be replaced and ties which are causing chafing or abrasion of the plant shall be adjusted.

(d) Firming up plants:

Plants which become loose as a result of wind, rock or other causes shall be firmed up.

(e) Watering:

(i) Fresh water shall be used for watering landscape softworks. Water shall be

applied using a rose or sprinkler of a type reviewed without objection by the Project Manager and in such a manner that compaction, washout of soil or loosening of plants will not be caused; any damage caused shall be made good immediately.

(ii) All planted areas shall be watered to ensure successful establishment of the

plant. Any plant reaching permanent wilting point shall be watered immediately.

(iii) An inspection to determine water requirements shall be made in dry weather by

the Contractor and the Project Manager twice weekly.

(iv) The Contractor shall complete watering operations within 24 hours of an instruction from the Project Manager.

(f) Weeding:

(i) All grassed and planted areas shall be kept free from weeds throughout the

period for establishment works.

(ii) Weeding shall be carried out by hand or by mechanical methods reviewed without objection by the Project Manager provided in all cases that no damage to the grass and planted areas will be caused. All weeds, litter and other rubbish resulting from the weeding operation shall be disposed of by the Contractor.


(iii) Planted areas in bare ground shall be weeded to remove all unwanted vegetative growth including aerial parts and roots, over the complete area. Planted areas other than in bare ground shall be weeded to remove all competing and overhanging vegetative growth by cutting the growth down to not more than 50 mm above soil level.

(g) Pruning:

Pruning and removal of branches shall be carried out using sharp, clean implements. Pruning shall be carried out with the cut just above and sloping away from an outward facing healthy bud. Removal of branches shall be carried out by cutting outside of a line drawn between the branch bark ridge and the branch collar in such a way that no part of the stem is damaged or torn, and leaving no snags or stumps.

(h) Grass cutting:

(i) Grassed areas shall be cut by manual or mechanical methods reviewed without

objection by the Project Manager and in such a manner that does not cause pulling of roots or damage to planting in or near the grassed area. All cuttings shall be raked off and disposed of within 24 hours after cutting.

(ii) Category 1 grass shall be as stated in the Contract and shall be reduced by

cutting to a height of 50 mm when it reaches 100 mm high.

(iii) Category 2 grass shall be as stated in the Contract and shall be reduced by cutting to a height of 100 mm when it reaches 300 mm high.

(iv) Category 3 grass cutting shall be cutting of areas of hydroseeding which are

stated in the Contract to be subsequently maintained as mown grass.

(i) Litter collection:

All litter exposed by grass cutting shall be gathered up and disposed of within 24 hours.

(j) Post-planting fertilizer:

Post-planting fertilizer shall be applied not less than 100 days, and not more than 300 days, after grassing or planting. The fertilizer shall be applied at a rate of :

(i) 100 g/m² for amenity grass and shrub planting;

(ii) 100 g for each light standard, standard and heavy standard tree;

(iii) 50 g for each seedling and whip tree; and

(iv) 40 g/m² for grass on slopes and grass grown by hydroseeding.

(k) Control of pests and disease:

Pesticide or fungicide shall be applied in accordance with the manufacturer's recommendations to control pests and disease.


(l) Forking over:

Surfaces of bare ground which are subject to surface panning or compaction of the soil shall be forked over in such a manner that roots are not disturbed and plants are not loosened; plants which are disturbed or loosened shall be firmed up and well watered immediately.

(m) Mulching:

All mulch which is disturbed by replacement planting, weeding or watering shall be made good. The Contractor shall also provide additional mulching over areas of forking-over and over areas disturbed by others.

(n) Completion of work:

Immediately before the end of the period for establishment works :

(i) all tree and shrub planting shall be free from weeds;

(ii) all planted and grassed areas shall be free from litter;

(iii) all replacement planting and patching up of grass shall be completed;

(iv) all stakes and ties shall be secure; and

(v) all grassed areas shall be cut and the edges trimmed.

4.7 INSPECTION, TESTING AND COMMISSIONING 4.7.1 Testing : Grass Cover

(a) Tests shall be carried out to determine the grass cover. The tests shall be carried out 100 days after grassing and at the end of the period for establishment works. The grass shall be cut to a height of 300 mm if necessary over the parts of the area to be tested.

(b) The method and number of tests shall be reviewed without objection by the Project

Manager.

(c) Testing to determine the grass cover will be carried out by the Contractor in the presence of the Project Manager.

(d) Tests shall be carried out at locations which are representative of the grassed area as a

whole. At each test location an approximately square area of 10 m² shall be marked.

(e) The percentage of bare ground other than rock and other hard material in each 10 m² test area shall be measured.

(f) At least 90% of each test area shall be covered with grass. (g) If the result of any test for grass cover of landscape softworks and establishment

works does not comply with the specified requirements for gross cover the area shall be rehydroseeded or reseeded in accordance with Clause 4.6.4(f)(i) or (ii) determined by the Project Manager, depending upon the size of the defective area.


4.7.2 Inspection of Establishment Works

An inspection of landscape softworks and establishment works shall be carried out jointly by the Contractor and the Project Manager at monthly intervals to determine the establishment works which are required. The Project Manager shall instruct the Contractor to carry out establishment works which are necessary; the work instructed shall be completed within 14 days after the date of the Project Manager's instruction.


APPENDIX A4.1

BRITISH STANDARDS PUBLICATIONS

B.S. 1992 : Part 4 : 1984

Recommendation for landscape drawings

B.S. 3882 : 1965 (1978)

Recommendation and classification for top soil

B.S. 3936 :

Specification for nursery stock : Part 1 : 1980 Specification for trees and shrubs : Part 4 : 1980 Specification for forest trees : Part 9 : 1968 Bulbs, corms and tubers : Part 10 : 1981 Specification for ground cover plants

B.S. 3969 : 1968 (1975)

Recommendations for turf for general landscape purposes

B.S. 3975 :

Glossary for landscape work : Part 4 : 1966 Plant description : Part 5 : 1969 Horticultural, arboricultural and forestry practice

B.S. 3998 : 1989 Recommendations for tree work

B.S. 4043 : 1989 Recommendations for transplanting root-balled trees

B.S. 4156 : 1967 (1979) Peat

B.S. 4428 : 1989 Recommendations for general landscape operations (excluding hard surfaces)

B.S. 5236 : 1975 Recommendations for the cultivation and planting of trees in the advanced nursery stock category

B.S. 5551 : Fertilizers

B.S. 5837 : 1980

Code of practice for trees in relation to construction (under review)

HONG KONG GOVERNMENT PUBLICATIONS

SIL Technical Guide to Tree Planting and Maintenance


SECTION 5 FENCING 5.1 GENERAL

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section:

(a) handrailing shall comply with Section 35; (b) earthworks shall comply with Section 7; (c) pedestrian guardrailing shall comply with Section 11; (d) formwork and finishes to concrete shall comply with Section 18; (e) reinforcement shall comply with Section 19; (f) concrete shall comply with Section 20; (g) steelwork shall comply with Section 22; and (h) vehicular parapets shall comply with Section 23.

5.2 DESIGN AND PERFORMANCE CRITERIA 5.2.1 Acrylic Sheet Sound Barriers

(a) The design working load for acrylic sheets shall be 6.9 kPa. Each panel shall be assumed to be simply supported unless the Contractor can demonstrate the amount of fixity that the support can offer either by test on Site which is acceptable to the Project Manager or by producing satisfactory test results performed under similar conditions.

(b) Movement joints shall be designed to allow for thermal movement of the sheeting due

to a temperature variation of ±50º and the movement of the structure without affecting their performance in any respect. Sealing compounds, taps and gaskets should be sufficiently flexible to permit movement of the sheeting.

5.3 MATERIALS 5.3.1 Wire

(a) Wire for fencing, including plastic coated wire, shall be galvanised mild steel complying with BS 4102.

(b) Barbed wire shall consist of two line wires and point wire formed in accordance with

BS 4102, Clause 4.1. (c) Galvanised coatings to steel wire shall comply with BS 443. (d) Plastic coatings to steel wire shall comply with BS 4102, Section 6.


5.3.2 Chain Link Fence

Chain link fence shall comply with BS 1722 Part 1. 5.3.3 Plywood

Plywood for hoardings shall comply with BS 6566 and shall have a grade 2 veneer. The bonding adhesive between veneer layers shall be phenol formaldehyde resin adhesive, classified as weather-proof and boil-proof in accordance with BS 1203.

5.3.4 Timber

(a) Timber for fencing shall be of mature growth and shall be seasoned and free from large, loose or dead knots, wood wasp holes, infestation, splits and other defects that will reduce the strength or produce blemishes. The moisture content in timber at the time of fabrication shall not exceed 20%.

(b) Hardwood shall be ‘San Cheung’ (Kapore) and shall have a minimum density of 720

kg/m3 at 15% moisture content. (c) Softwood shall be cedar, spruce or China fir. (d) Timber that is not to be painted shall be preserved with coal tar creosote. The creosote

shall comply and be applied by pressure impregnation in accordance with BS 144. 5.3.5 Steel

(a) Steel for fencing shall comply with the following:

(i) Hot rolled Sections BS 4 Part 1;

(ii) Hot rolled structural Sections:

- Equal and unequal angles BS 4848 : Part 4;

- Hollow Sections BS 4848 : Part 2; and

(iii) Metal washers for general engineering purposes BS 4360.

5.3.6 Bolts, Nuts, Washers and Fittings

(a) Bolts, nuts and washers for fences shall comply with the following:

(i) ISO metric black hexagon bolts, screws and nuts BS 4190;

(ii) ISO metric black cup and countersunk head bolts and screws with hexagon nuts

BS 4933; and

(iii) Metal washers for general engineering purposes BS 4320.

(b) The length of bolts shall be such that the threaded portion of each bolt projects

through the nut by at least one and not more than four, threads. (c) Fittings, including eye bolt strainers, cleats, winding brackets, stretcher bars, extension

arms, hook bolts and base plates, shall be galvanised mild steel.

(d) Bolts, nuts, washers and fittings for fixing to concrete and timber shall be galvanised. Bolts, nuts, washers and fittings for fixing to steel shall have the same protective treatment as the steel.


(e) Staples shall be “D” Section galvanised wire. 5.3.7 Acrylic Sheet Sound Barriers

(a) Acrylic sheets for sound barriers shall be manufactured from polymethylmethacrylate resin and shall be supplied and erected by a proprietary manufacturer acceptable to the Project Manager.

(b) The light transmission measured in accordance with DIN 5036 shall not be less than

90% for a 4 mm thick sample. (c) Acrylic sheets shall comply with BS 6262, and in no case be less than 15 mm thick.

The tolerance in thickness shall not exceed ±5%. (d) Acrylic sheets shall carry the manufacturer's guarantee under outdoor conditions in

Hong Kong on the following properties:

(i) Light transmittance; over a period of 10 years the light transmittance shall not decrease by more than 5% from the original value.

(ii) Modulus of elasticity; after 10 years the elastic modulus shall not be less than

2800 MPa

(iii) Tensile strength; after 10 years the tensile yield stress shall not be less than 60 MPa.

(e) Acrylic sheets shall have impact strength in compliance with Class A materials

according to BS 6206. (f) All exposed edges of acrylic sheets shall be polished. (g) All steel fixings and accessories shall have corrosion protection treatment not inferior

to the structural steel frame shown on the Employer’s Drawings and they shall be painted to the same colour as the structural steel frame.

(h) All acrylic sheets shall be covered with a protective sheeting to the manufacturer's

recommendation during transport, storage on Site, and construction until the application for the Completion Certificate

(i) Fixing details, which require drilling holes in the acrylic sheets are not acceptable.

5.3.8 Fabrication of Steelwork

Steelwork shall be fabricated in accordance with BS5950: Part 2.

5.3.9 Galvanising to Steel

(a) Steel to be galvanised shall be hot-dipped galvanised in accordance with BS 729 with a minimum coating thickness of 500 g/m2.

(b) Galvanising to steel shall be applied, as far as possible, after welding, drilling and/or

cutting are complete.


5.3.10 Welding Steel

(a) Welds to steel for fencing shall be in accordance with Clause 22.5.2. Weld surfaces shall be clean and flush before application of the protective coating.

(b) Steel shall not be welded after galvanising except with the express permission of the

Project Manager. If permitted, the welded areas shall be free from scale and slag and shall be treated after welding, with an alternative galvanising or zinc coating system, reviewed without objection by the Project Manager.

5.3.11 Concrete Posts

(a) Concrete posts and struts for fencing shall be precast units using Grade 30/10 concrete. The finish to formed surfaces shall be Class F4 and the finish to unformed surfaces shall be Class U5. The tops of posts and all arises shall be rounded or chamfered.

(b) Reinforcement for concrete posts and struts shall be Grade 250 plain round steel bars. (c) No concrete posts shall be removed from the mould for a period of at least 24 hours

and shall not be shifted or transported until at least seven days have elapsed since casting.

5.3.12 Gates

(a) Steel gates shall be of welded construction. The frame shall be square with the corners mitred or saddled.

(b) Chain link infilling in gates shall be of the same type and size as in the adjoining fence

and shall be attached to the framework by stretcher bars. 5.3.13 Storage of Fencing

(a) Plywood and timber posts, rails and struts for fencing shall be stored on level supports in a dry, weatherproof store.

(b) Gates, concrete and steel posts and struts for fencing shall be stored off the ground on

level supports. (c) Damaged fencing materials shall not be used in the Works.

5.4 SUBMISSIONS 5.4.1 Particulars of Fencing

The following particulars of the proposed fencing shall be submitted to the Project Manager for review:

(a) Contractor’s Drawings showing the fabrication details of fences and gates; (b) details of the source, type and properties of all fencing materials; and (c) Contractor’s Drawings showing details, fixings and movement joints (including

calculations) for all acrylic sheet sound barriers.


5.4.2 Samples

The following samples of the proposed materials shall be submitted to the Project Manager together with the particulars referred to Clause 5.4.1 above:

(a) each type of wire and fitting; (b) chain link; (c) acrylic sound barriers; (d) plywood; and (e) precast concrete, steel and timber posts.

5.5 WORKMANSHIP 5.5.1 Tolerances

Fencing shall comply with the following requirements:

(a) the position of posts shall be within 75 mm of the specified position; (b) the level of the top of posts shall be within 25 mm of the specified level; and (c) posts shall be vertical to within 5 mm over the height of the post.

5.5.2 Alignment of Fencing

Fencing shall be erected to a smooth alignment with no abrupt irregularities. The ground shall be trimmed or filled in such a manner that the bottom of the fence will approximately follow the level of the ground. The distance between the bottom of either chain link mesh or hoardings, and the ground, shall not exceed 100 mm.

5.5.3 Posts for Fencing

(a) Straining posts for fencing shall be provided at all ends and corners, at changes in direction, at abrupt changes in level, at gate posts and at intervals not exceeding 30 m along straight lengths of fencing. Struts shall be fitted to straining posts in the direction of each wire secured to the post.

(b) Intermediate posts shall be provided at intervals not exceeding 3.5 m.

5.5.4 Erecting Posts for Fencing

(a) Posts and struts for fencing shall be set in excavations for foundations and the excavations shall be filled with Grade 30/20 concrete up to 50 mm below ground level.

(b) Struts shall be fitted into slots in timber and concrete posts and bolted to steel posts. (c) The ground surface around posts shall be made good with the same material as in the

adjoining area.


5.5.5 Fixing Wire for Fencing

(a) Line wire, chain link mesh and barbed wire for fencing shall be strained tightly between straining posts. Winding brackets shall be used for straining between steel posts. Winding brackets or eye bolt strainers shall be used for straining between concrete and timber posts. The tension in the wire on each side of straining posts shall be equal. Wire shall not be strained until at least 14 days after concrete has been placed in the foundation.

(b) Chain link mesh shall be secured at each straining post by a stretcher bar and shall be

tied to the line wire by tying wire at 150 mm intervals.

(c) Each line wire and each line of barbed wire shall be secured to each intermediate post by one of the following methods as stated in Table 5.1:

(i) a hairpin staple shall be passed through a hole in the post and secured to the

wire by three complete turns on each side of the post;

(ii) a stirrup shall be passed through a hole in the post and the ends bent over twice;

(iii) the wire shall be threaded through a hole in the post;

(iv) the wire shall be stapled to the post; or

(v) a hook bolt shall be passed through a hole in the post and secured with a nut and washer.

Table 5.1: Method of Securing Wire to Intermediate Posts

Type of Fence Type of Wire Type of Post Method of Securing Wire

Concrete (i), (ii) or (iii) Steel (i), (ii) or (iii)

Line wire

Timber (i), (ii) or (iv) Concrete (i) or (ii) Steel (i)

Strained Wire

Barbed wire

Timber (i) or (iv) Concrete (i), (ii) or (v) Steel (i) or (iii)

Line wire, mesh wire

Timber (iv) Concrete (i), (ii) or (v) Steel (i)

Chain link

Barbed wire

Timber (iv)

5.5.6 Fixing Gates

Gates shall be hung plumb and shall not be installed until the wire has been strained.

5.5.7 Fixing Timber for Fencing

The ends of timber rails for fencing shall be closely butted together and the rails shall be securely nailed to each post. The ends of plywood sheets in hoardings shall be closely butted together and the sheets shall be securely nailed to each post and to the horizontal rails.


SECTION 6 DRAINAGE WORKS

6.1 GENERAL The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section. (a) Metalwork for handrailing, ladders, stairs, metal flooring, toe plates and safety chains

shall comply with Section 35 and Section 22.

(b) Earthworks shall comply with Section 7.

(c) Formwork and finishes to concrete shall comply with Section 18.

(d) Steel reinforcement shall comply with Section 19.

(e) Concrete shall comply with Section 20.

(f) Materials for grout shall comply with Section 20.

(g) Water supply pipeworks shall comply with Section 14.

(h) Cable duct systems for electrical and mechanical installations shall comply with Section 13.

6.2 GLOSSARY OF TERMS

6.2.1 Pipes Pipes for drainage works are pipes for conveying sewage and surface water.

6.3 MATERIALS

6.3.1 Precast Concrete Pipes and Fittings (a) Precast concrete pipes and fittings shall comply with BS 5911:Part 100.

(b) Precast concrete pipes and fittings shall have flexible spigot and socket joints.

6.3.2 Vitrified Clay Pipes and Fittings (a) Vitrified clay pipes and fittings shall comply with BS 65; the pipes and fittings shall

be glazed and shall be the chemical resistant type.

(b) Vitrified clay pipes and fittings shall have flexible mechanical joints.

6.3.3 DI Pipes and Fittings (a) DI pipes and fittings shall comply with BS 4772. Pipes and fittings shall be lined

internally with cement mortar in accordance with BS 4772, Appendix C. Pipes and fitting shall be coated externally with bituminous coating in accordance with BS 4772 Section 16.3.


(b) Flexible joints in DI pipes and fittings shall be the push-in type and shall be capable of withstanding a minimum angular deflection of 4. Flexible joints shall also be capable of withstanding axial movements and shall allow a minimum withdrawal of 38 mm when there is no deflection of the joint.

(c) Flanged joints in DI pipes and fittings shall be PN 16 rating complying with BS 4504:

Section 3.1.

(d) Pipes to be built in to structures shall have puddle flanges welded on.

6.3.4 Grey Iron Pipes and Fittings Grey iron pipes and fittings shall comply with BS 4622.

6.3.5 UPVC Pipes and Fittings (a) Unplasticised (UPVC) pipes and fittings shall comply with the relevant British

Standard stated in Table 6.1.

(b) UPVC pipes and fittings above ground shall have solvent welded spigot and socket joints. UPVC pipes and fittings below ground shall have either solvent welded spigot and socket joints or flexible spigot and socket joints with elastomeric joint rings as stated in the Contract.

(c) Joints and fittings for UPVC pressure pipes complying with BS 3506 shall comply

with the following:

(i) injection moulded UPVC fittings for solvent welding for use with pressure pipes, including water supply : BS 4346: Part 1; and (ii) mechanical joints and fittings principally of UPVC : BS 4346: Part 2.

(d) Solvent cement for UPVC pressure pipes shall comply with BS 4346: Part 3. (e) The class of UPVC pressure pipes complying with BS 3506 shall depend on the

pressure rating.

6.3.6 GI Pipes and Fittings (a) GI pipes and fittings shall comply with the following:

(i) steel tubes and tubulars suitable for screwing to BS 21 pipe threads : BS 1387, medium grade; (ii) pipe threads for tubes and fittings where pressure-tight joints are made on the threads : BS 21; and (iii) wrought steel pipe fittings (screwed BSP thread) : BS 1740: Part 1.

(b) GI pipes and fittings shall be medium class thickness and shall be galvanized in

accordance with BS 729.


Table 6.1: UPVC Pipes and Fittings

Use Nominal diameter (mm) British Standard

32 - 50 BS 5255 Gravity sewage pipes and fittings above ground 82 - 160 BS 4514

63 - 75 BS 4576: Part1 Gravity surface water pipes and fittings above ground 82 - 160 BS 4514

110 - 160 BS 4660 Gravity sewage and storm water pipes and fittings below ground

200 - 630 BS 5481

Pressure pipes and fittings above and below ground

10 - 600 BS 3506

6.3.7 Bolts, Nuts and Washers

(a) Bolts, nuts and washers for flanged joints, detachable couplings and flange adapters

shall comply with the following:

(i) ISO metric black hexagon bolts, screws and nuts : BS 4190; (ii) metal washers for general engineering purposes : BS 4320; and (iii) the bolts, nuts and washers shall be hot-dip galvanised in accordance with BS

729. (b) Stainless steel bolts and nuts shall comply with BS 6105, steel Grade A4 and property

Class 80. Washers shall be Grade 316 S 31 in the softened condition complying with BS 1449: Part 2.

(c) Spheroidal graphite iron bolts shall be Grade 500/7 metal complying with BS 2789. (d) Bolts, nuts and washers shall be insulated from electrochemically dissimilar metal by

non-metallic washers and sleeves. (e) Bolts and nuts shall be compatible with the type of joint and shall be obtained from

the same manufacturer as the joint. (f) The length of bolts shall be such that the threaded portion of each bolt projects

through the nut by at least one thread and by not more than four threads.

6.3.8 Elastomeric Joint Rings (a) Elastomeric joint rings shall comply with BS 2494, Type D. The rings shall be

compatible with the type of joint and shall be obtained from the same manufacturer as the joint.

(b) Elastomeric joint rings for flanged pipes shall be the inside diameter bolt circle type.

The rings shall be natural rubber with a thickness of 3.2 mm and with other dimensions complying with BS 4865: Part 1.


6.3.9 Detachable Couplings and Flange Adapters (a) Detachable couplings and flange adapters shall be a proprietary type reviewed without

objection by the Project Manager. (b) Detachable couplings and flange adapters shall accommodate the angular deflection

and straight draw stated in Table 6.2 for the different nominal diameters of pipes connected.

Table 6.2: Angular Deflection and Straight Draw

Detachable coupling Flange adapter Nominal diameter Angular

deflection Straight

draw Angular

deflection Straight

draw not exceeding 450 mm ± 6° ± 10mm ± 3° ± 5mm exceeding 450 mm and not exceeding 600 mm

± 5° ± 2.5°

exceeding 600 mm and not exceeding 750 mm

± 4° ± 2°


± 3° ± 1.5°


± 2° ± 1°

exceeding 1800 mm ± 1° ± 0.5°

6.3.10 Anticorrosion Tape (a) Anticorrosion tape shall be a proprietary type reviewed without objection by the

Project Manager. The tape shall be a rubber/bitumen compound with fabric reinforcement and shall be backed with PVC film. The tape shall have a high resistance to cathodic disbonding, acids and alkalis and shall have the minimum properties stated in Table 6.3.

(b) Anticorrosion tape shall be applied to valves, flanged joints, slip-on couplings and

flange adapters. Type 1 shall be used for pipes smaller than 700 mm diameter and Type 2 shall be used for pipes 700 mm diameter and above.

(c) Primer and mastic filler for use with anticorrosion tape shall be compatible with the

tape and shall be a type recommended by the manufacturer of the tape and reviewed without objection by the Project Manager.

Table 6.3: Properties of Anticorrosion Tape (except where stated the values shown are minimum values)

Value Property

Type 1 Type 2

Thickness of PVC backing (m) 85 500

Tensile strength (N/mm) 8 10

Elongation (%) 26 26

Tear strength (N) 20 36

Adhesion strength (N/mm) 2 2


Value Property

Type 1 Type 2

Holiday test voltage (kV) - single layer - double layer

10 15

10 15

Impact strength (J) 3.5 8

Temperature range (C) 5 - 60 8 - 60 Total thickness (mm) 1.6 2.0

Mass (kg/m2) 1.8 2.4

6.3.11 Bituminous Coatings

(a) Bituminous coatings shall comply with the following:

(i) bitumen based hot applied coating material for protecting iron and steel including suitable primers where required : BS 4147, Type I, Grade C (ii) black bitumen coating solutions for cold application : BS 3416, Type II.

(b) Bituminous coatings used for repairing joints and coatings shall be compatible with the adjacent coating.

6.3.12 Aggregates for Granular Bed and Granular Fill

(a) Granular bed shall be Type A material and granular fill shall be Type B material.

(b) Type A or Type B material shall consist of hard, clean, crushed slag, gravel, crushed

rock, crushed concrete or crushed inert demolition material having a grading within the limits of Table 6.4. The ten percent fines values shall be at least 50kN. The material passing the 425m BS test sieve shall be non-plastic when tested in accordance with BS1377.

(c) Type A and Type B material shall be obtained from a source reviewed without objection by the Project Manager.

(d) Aggregates for granular bed shall have the compacting fraction values stated in Clause 6.6.3(d).

Table 6.4: Type of Aggregates for Granular Bed BS test sieve Percentage by mass passing

Metric Type A Type B

63 mm

37.5 mm

20 mm

10 mm

3.35 mm

600 mm

75 mm

-

100

-

45 – 100

25 – 80

8 – 45

0 – 10

100

85 – 100

0 – 20

0 – 5

-

-

-


6.3.13 Joint Filler and Compressible Padding (a) Joint filler for joints in concrete bed, haunch and surround shall be a proprietary type

reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler. The thickness of the filler shall be as stated in Table 6.5.

(b) Compressible padding between pipes and supports shall be bitumen damp-proof

sheeting complying with BS 743. Table 6.5: Joint Filler for Concrete Bed, Haunch and Surround

Nominal diameter of pipe Thickness of joint filler (mm)

less than 450 mm 18

450 mm - 1200 mm 36

exceeding 1200 mm 54

6.3.14 Polyethylene Sheeting

Polyethylene sheeting shall be impermeable and shall have a nominal thickness of 0.125 mm.

6.3.15 Precast Concrete Manholes Precast concrete manhole units shall comply with BS 5911: Part 200. Cover slabs and reducing slabs shall be reinforced as required to comply with the load test requirements stated in BS 5911: Part 200. The type of cement for the manufacture of precast concrete manhole units, cover slabs, and reducing slabs shall be as stated in BS 5911: Part 200, or combination of PFA and OPC complying with BS 12, or PPFAC. The PFA content shall not exceed 40% by mass of the cementitious content.

6.3.16 Chambers and Gullies (a) Precast concrete chambers and gullies shall comply with BS 5911: Part 2. Cover

slabs shall be reinforced as required to comply with the load test requirements stated in BS 5911: Part 2. The types of cement for the manufacture of precast concrete chambers and gullies, and cover slabs shall be as stated in BS 5911: Part 2, or a combination of PFA and OPC complying with BS 12, or PPFAC. The PFA content shall not exceed 40% by mass of the cementitious content.

(b) Vitrified clay gullies shall comply with BS 65.

6.3.17 Step Irons Step irons shall comply with BS 1247. Step irons shall be malleable cast iron complying with BS 6681 and shall be hot-dip galvanised in accordance with BS 729.

6.3.18 Manhole Covers, Gully Gratings and Kerb Overflow Weirs (a) Manhole covers, gully gratings and kerb overflow weirs shall be Grade 50 cast iron

complying with BS 1452; bolts and nuts shall comply with BS 4190.


(b) Covers, gratings and weirs shall be cleanly cast, free from air holes, sand holes, cold shuts and chill and shall be neatly dressed and fettled. Castings shall be free from voids whether due to shrinkage, gas inclusions or other causes. Bolts and nuts shall not be over tightened.

(c) The dimensions of the different types of covers, gratings and weirs shall be as stated

in the Contract; the test loads which the covers and gratings are required to withstand, and the minimum masses of covers gratings and weirs, shall be as stated in Tables 6.6, 6.7 and 6.8.

(d) Covers, gratings and weirs shall have the manufacturer's name cast integrally with the

unit in a raised form and shall be protected with bituminous coating. Covers shall have a raised design on the top surface as stated in the Contract.

(e) The Contractor shall provide the Project Manager two keys for each pattern of cover

used. Table: 6.6: Details of Manhole Covers and Frames

Test requirements Type of manhole cover and frame

Minimum

mass (kg)

Grade Diameter of block

(mm)

Test load (t)

Double triangular manhole cover and frame

180 Medium duty 100 5

Double triangular manhole cover for sewers

130 Heavy duty 300 30

Frame 105 Heavy duty 300 30

Double triangular desilting manhole cover for sewers Frame

290

165

Heavy duty

Heavy duty

300

300

30

30

Double seal terminal manhole cover for sewers - Type MA2-29/29A & B - Type MA2-45/45A & B - Type MC2-29/29A & B - Type MC2-45/45A & B

- - - -

Heavy duty Heavy duty

Medium duty Medium duty

300 300 100 100

20 20 5 5


Table 6.7: Details of Gully Gratings and Frames

Test requirements Type of gully grating and frame

Minimum mass (kg)

Grade Diameter of block

(mm)

Test load (t)

Grating for hinged gully grating Type GA2-325 Frame

28.0

24.5

Heavy duty

Heavy duty

300

300

20

20 Grating for double triangular gully grating Type GA1-450 Shallow frame - adjacent to kerb - away from kerb Deep frame - adjacent to kerb - away from kerb

57.5

33.5 36.5

40.5 44.0

Heavy duty



300

300 300

300 300

20

20 20

20 20

Grating for hinged gully grating Type GA2-450 Frame

61.5

37.0

Heavy duty

Heavy duty

300

300

20

20 Table 6.8: Details of Kerb Overflow Weirs

Type of kerb overflow weir Minimum mass (kg)

Type 1-325 39.5

Type 3-325 31.5

Type 1-450 44.0

Type 3-450 36.5

Type 4-450 33.0

6.3.19 Penstocks

(a) Penstocks shall comply with the following requirements:

(i) frames and gates shall be cast iron complying with BS 1452, Grade 220; (ii) stems shall be stainless steel complying with BS 970: Part 1, Grade 316 S 31; (iii) operating nuts shall be gunmetal complying with BS 1400, Grade LG2; (iv) sealing faces shall be phosphor bronze complying with BS 2874, Grade PB

102; (v) sealing strips at inverts of flush invert penstocks shall be elastomer complying

with ASTM D 2000; (vi) assembly and fixing nuts and bolts shall be stainless steel complying with

Clause 6.3.7(b); and (vii) adjustable wedges shall be phosphor bronze complying with BS 2874, Grade

PB 102 or stainless steel complying with BS 970: Part 1, Grade 316 S 31.


(b) Penstocks shall be designed for on-seating pressure or off-seating pressure or both on-seating and off-seating pressures as stated in the Contract.

(c) Sealing faces shall be of rectangular sections and shall be fixed to the frames and

gates using taperhead screws of the same material as the sealing faces. (d) Adjustable wedges shall have sufficient contact areas with the gates to minimise wear. (e) Frames shall include guide rails or guide faces for gates. Clearance within guides

shall be as small as practicable such that the gates will not vibrate under flow conditions.

(f) Penstocks shall have rising stems unless otherwise stated in the Contract. Rising

stems shall have perspex protection tubes with open/close indicators.

6.3.20 Gate Valves (a) Gate valves shall comply with BS 5150 and with the following requirements:

(i) bodies and wedges shall be cast iron complying with BS 1452, Grade 220 and shall have renewable gunmetal seat rings;

(ii) gunmetal for renewable seat rings shall be Grade LG2 complying with BS

1400; (iii) stem nuts shall be gunmetal complying with BS 1400, Grade LG2; (iv) stems shall be aluminium bronze complying with BS 2874, Grade CA 104; and (v) assembly and fixing nuts and bolts shall be stainless steel complying with

Clause 6.3.7(b). (b) Gate valves shall be double flange-ended solid wedge type with nominal pressure

designation PN 16. Flanges shall be PN 16 complying with BS 4504: Part 1. (c) Gate valves shall have outside screw rising stems unless otherwise stated in the

Contract. Rising stems shall have perspex protection tubes with open/close indicators.

(d) Gate valves shall be fitted with a plate showing the operating position of the valve in

the closed, quarter closed, half closed, three-quarters closed and open positions. (e) Chains for chain operated gate valves shall be mild steel complying with BS 970:Part

1 and hot-dip galvanized in accordance with BS 729. The chains shall be continuous.

6.3.21 Flap Valves (a) Flap valves shall comply with the following requirements:

(i) frames and flaps shall be cast iron complying with BS 1452, Grade 220; and (ii) sealing faces and hinge pins shall be gunmetal complying with BS 1400, Grade

LG2. (b) The flap shall be hung with double hinges and secured with hinge pins.


(c) Flanges for flange mounting types of flap valves shall be PN 16 complying with BS 4504: Part 1.

6.3.22 Sludge Valves

(a) Sludge valves shall comply with the following requirements:

(i) bodies and valve sections shall be cast iron complying with BS 1452, Grade 220;

(ii) sealing faces and stem nuts shall be gunmetal complying with BS 1400, Grade

LG2; and (iii) stems shall be aluminium bronze complying with BS 2874, Grade CA 104.

(b) The stems of sludge valves shall operate through non-rising stem nuts housed in

bridges bolted over the body sections. (c) Outlet flanges of sludge valves shall be PN 16 complying with BS 4504: Section 3.1.

6.3.23 Air Valves (a) Air valves shall be of the elongated body type and shall have a pressure rating of 3

bars unless otherwise stated in the Contract.

(b) Dual orifice air valves shall have:

(i) a small orifice valve for releasing air at working pressure, and (ii) a large orifice valve for allowing air to pass at atmospheric pressure during

emptying and filling of pipework. (c) The bodies and covers of small and large orifice valves shall be cast iron complying

with BS 1452, Grade 220; the trim and float shall be stainless steel complying with BS 970:Part 1, Grade 316 S 31.

(d) Small orifice valves shall have an adjustable Vitron or equivalent orifice button to

ensure positive sealing. Large orifice valves shall have a Buna-N or equivalent seat. (e) The valve inlet of small orifice valves shall be 75 mm diameter and the valve outlet

shall be 25 mm diameter; the venting orifice shall be 5 mm diameter. The valve inlet and the valve outlet of large orifice valves shall be 75 mm diameter.

(f) Air valves shall be provided with isolating gate valves.

6.3.24 Fittings for Penstocks and Valves (a) Handwheels and tee keys for penstocks and valves shall turn in a clockwise direction

for closing. Handwheels shall have smooth rims and the direction of opening and closing shall be clearly cast on the handwheel. The opening effort required at any point on the handwheel rim shall not exceed 250 N when operated against the full unbalanced pressure.

(b) Extension stems for penstocks and valves shall be stainless steel of the same grade as

the stems. Extension stems shall be connected by muff couplings.


(c) Handwheels, tee keys, headstocks, guide brackets for stems, supporting brackets, surface boxes and other fittings for penstocks and valves shall be cast iron complying with BS 1452.

(d) Bolts and nuts for fixing penstocks and valves to structures shall be stainless steel

complying with Clause 6.3.7(b). Bolts shall be indented foundation bolts. (e) Grout for filling rebates and box-outs shall be a proprietary type reviewed without

objection by the Project Manager and shall contain a non-shrink admixture.

6.3.25 Foam Concrete Foam concrete for filling abandoned pipes, culverts, manholes and voids shall be composed of OPC (or PPFAC), fine aggregate, water, admixtures for accelerating or retarding the setting time and foam to reduce the density and to produce a flowing self levelling material.

6.4 SUBMISSIONS

6.4.1 Particulars of Pipes, Joints and Fittings (a) The following particulars of the proposed pipes, joints and fittings for drainage works

shall be submitted to the Project Manager for review:

(i) manufacturers' literature, including details of: - manufacturing process; - pressure and temperature ratings; - permissible values of straight draws and angular deflection of flexible joints; - recommendations for handling, storage, laying, jointing and repair; and - drilling and tapping equipment for connections to pipes; and

(ii) a certificate for each material showing the manufacturer's name, the date and

place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard.

6.4.2 Particulars of Anticorrosion Tape and Joint Filler

(a) The following particulars of the proposed anti-corrosion tape and joint filler for

drainage works shall be submitted to the Project Manager for review:

(i) manufacturer's literature for the joint filler and anticorrosion tape; and

(ii) certificates for anticorrosion tape and joint filler showing the manufacturers' name, the date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests in accordance with the Contract.

6.4.3 Particulars of Aggregates for Granular Bed

A certificate for each type of aggregate showing the source of the aggregate and showing that the aggregate complies with the requirements stated in the Contract, and including the results of tests in accordance with the Contract, shall be submitted to the Project Manager for review for the proposed aggregates for granular bed for drainage works.


6.4.4 Particulars of Manholes, Chambers and Gullies (a) The following particulars of the proposed materials for manholes, chambers and

gullies for drainage works shall be submitted to the Project Manager for review:

(i) a certificate for each type of manhole and chamber unit and for each type of gully showing the manufacturer's name, the date and place of manufacture and showing that the materials comply with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard;

(ii) a certificate for step irons showing the manufacturer's name, the date and place

of manufacture and showing that the step irons comply with the requirements stated in the Contract, and including results of tests required in accordance with the Contract; and

(iii) a certificate for each type of manhole cover, gully grating and kerb overflow

weir showing the manufacturer's name, the date and place of manufacture and showing that the materials comply with the requirements stated in the Contract and including results of loading tests in accordance with the Contract.

6.4.5 Particulars of Penstocks and Valves

(a) The following particulars of the proposed penstocks and valves for drainage works

shall be submitted to the Project Manager for review:

(i) manufacturer's literature, including details of: - materials; - pressure ratings; and - recommendations for handling, storage and installation; and

(ii) Contractor’s Drawings showing details of the penstocks and valves, including lengths of stems and details of handwheels, tee keys, extension stems, headstocks, guide brackets for stems, supporting brackets, surface boxes and other fittings, and positions and sizes of rebates and box-outs.

6.4.6 Particulars of Foam Concrete and OPC/PFA Grout

(a) The following particulars of the foam concrete mix (or grout mix) and procedure for

filling abandoned pipes, culverts, manholes and voids shall be submitted to the Project Manager for review:

(i) proportions of each constituent;

(ii) source of supply; (iii) details of mixing; (iv) setting time; (v) strength; (vi) shrinkage expected (for OPC/PFA grout);


(vii) details of mixing and grouting equipment; and (viii) method of grouting, including details of trials.

6.4.7 Particulars of Tests

(a) The following particulars of the proposed procedures for tests on pipelines and

penstocks for drainage works shall be submitted to the Project Manager for review:

(i) test equipment and method of setting up the equipment; (ii) calibration certificates for pressure gauges; (iii) procedure for carrying out the test; and (iv) programme for testing.

6.4.8 Particulars of CCTV Inspections

(a) The following particulars of the proposed procedure for CCTV inspections shall be

submitted to the Project Manager for review:

(i) names and experience of persons carrying out or supervising the inspections; (ii) details of equipment; (iii) details of the format of report; and

(iv) examples of video films and photographs obtained from inspections employing

the same equipment.

6.4.9 Particulars of Diversions of Flow Particulars of the proposed procedures for diversions of existing flows shall be submitted to the Project Manager for review.

6.5 WORKMANSHIP

6.5.1 Transport, Handling and Storage of Materials

(a) Transport, handling and storage of pipes, joints and fittings:

(i) Pipes, joints and fittings for drainage works shall be transported, handled and stored in accordance with the manufacturers' recommendations and in a manner which will not result in damage or deformation to the pipes, joints and fittings or in contamination of the pipes, joints and fittings.

(ii) Pipes, joints and fittings shall be protected from damage and damaged pipes,

joints and fittings shall not be used in the Permanent Works. Pipes, joints and fittings shall be securely packed and supported to prevent movement when being transported.

(iii) UPVC pipes, joints and fittings shall be protected from exposure to conditions

which may affect the material.


(iv) Bolts and nuts shall be packed in sealed metal containers.

(v) Elastomeric joint rings shall be packed in bags and lubricant for joints shall be stored in sealed containers marked to identify the contents. The rings and lubricant shall be protected from exposure to conditions which may affect the material.

(b) Handling of pipes and fittings:

(i) Pipes and fittings shall be handled manually or by using lifting appliances or chains, wire ropes or canvas slings of a type recommended by the pipe manufacturer and reviewed without objection by the Project Manager. Hooks shall not be used.

(ii) Slings shall be placed around the pipes and fittings and padding shall be

provided at points of contact between pipes and fittings and metal lifting appliances or slings. Pipes and fittings shall not be handled by means of metal slings passed through the pipes.

(iii) Pipes and fittings shall not be subjected to rough handling, shock loading or

dropping. (c) Storage of pipes:

(i) Pipes shall be stored horizontally at least 75 mm above the ground on wedged timber bearers and shall not be strung out along the route of the pipeline. The pipes shall be securely wedged to prevent sideways movement.

(ii) Socket and spigot pipes shall be stored with the sockets alternating and in such

a manner that loads are not applied to the sockets.

(iii) The height of stacks of pipes shall not exceed the maximum height recommended by the pipe manufacturer.

(d) Storage of anticorrosion tape and joint filler:

Anticorrosion tape and joint filler shall be stored in accordance with the manufacturer's recommendations in a dry, weatherproof store with a raised floor.

(e) Handling and storage of aggregates for granular bed:

Aggregates for granular bed shall not be handled or stored in a manner which will result in mixing of the different types and sizes or in contamination of the aggregates. Different types and sizes of aggregates shall be stored in separate stockpiles.

(f) Handling and storage of units for manholes, chambers and gullies:

(i) Units for manholes, chambers and gullies shall be lifted only at the lifting points recommended by the manufacturer and shall not be subjected to rough handling, shock loading or dropping.


(ii) Units for manholes, chambers and gullies shall be stored off the ground on level supports and in a manner which will not result in damage or deformation to the units or in contamination of the units. The units shall be protected from damage and damaged or deformed units shall not be used in the Permanent Works.

(g) Storage of covers, gratings, weirs, penstocks and valves:

Manhole covers, gully gratings, kerb overflow weirs, penstocks and valves, including fittings, shall be stored off the ground on level supports and in a manner which will not result in damage to the units or in contamination or deformation of the units. The units shall be protected from damage and damaged or deformed units shall not be used in the Permanent Works.

6.5.2 Excavation

(a) Excavation for any section of a trench for drainage works shall not commence until

the nature, location and size of existing utilities which may be affected by the excavation have been ascertained and the setting out details have been reviewed without objection by the Project Manager.

(b) The effective trench width of trenches for drainage works shall not exceed the

relevant effective trench widths stated in Table 6.9 for the different diameters of pipe. Unless otherwise stated in the Contract, effective trench width for different trench profiles shall be measured in accordance with the requirements of the Hong Kong Government Drainage Services Department Standard Drawings.

Table 6.9: Effective Trench Widths

Nominal Diameter

of pipe (mm)

Effective trench width (mm)

Nominal diameter of pipe (mm)

Effective trench width (mm)

100 550 1125 2200 150 600 1200 2300 225 700 1350 2450 300 750 1500 2600 375 1050 1650 2800 450 1150 1800 2950 525 1200 1950 3150 600 1350 2100 3350 675 1450 2250 3400 750 1500 2400 3500 825 1600 2550 3650 900 1900 2700 3800 975 2000 2850 3950

1050 2050 3000 4150


(c) The bottom of the excavation shall be formed to the levels and falls as stated in the Contract and well rammed and consolidated. Any backfill in the areas of overbreak shall be provided by material reviewed without objection by the Project Manager.

(d) The sides of trenches, manholes and other excavations shall be adequately supported

at all times. Where shown on the Employer’s Drawings or directed by the Project Manager the supports shall be left in trenches or pits.

(e) The materials excavated in forming pipe drains shall, if containing materials as

defined in Clause 7.3.1(b), be disposed of off Site and replaced with fill material. Excavated fill material shall be set aside for use as fill.

(f) Surplus material shall be used for fill or disposed of in accordance with Clause 7.5.1

as agreed with, or directed by the Project Manager.

6.5.3 Laying and Bedding Pips (a) Laying pipes

(i) The Contractor shall allow the Project Manager to inspect trenches, bedding, pipes, joints, fittings and valves before pipelaying for drainage works starts. The Contractor shall notify the Project Manager before pipelaying starts in any part of the Permanent Works.

(ii) The Contractor shall inspect pipes, joints, fittings and valves, including internal

and external coatings, immediately before and after pipelaying; valves shall be inspected to ensure that they are in working order and are capable of being fully opened and closed. Deleterious material shall be removed and damage shall be repaired immediately before and after pipelaying.

(iii) The inside of pipelines shall be kept clean and free from water, dirt, stones,

debris and deleterious material. Except when pipes are being jointed, the open ends of pipelines shall be sealed with a wooden plug or stopper.

(iv) Measures shall be taken to prevent flotation of pipes.

(v) Pipelaying, testing and backfilling shall follow as closely as practicable on

excavation of the trench.

(vi) Pipelines shall be laid in an uphill direction with sockets facing uphill.

(vii) Pipes shall be laid in such a manner that water will not pond in locations with zero or shallow gradients and such that the pipes will comply with the specified tolerances.

(b) Bedding pipes

(i) Surfaces on which pipes for drainage works will be laid shall be cleaned and objects which may damage the pipes shall be removed before pipes are laid.

(ii) The bottom of trenches on which pipes will be laid directly shall be shaped to

support the pipes uniformly along the length of the barrel; holes shall be dug to prevent pipes resting on the sockets and to allow the pipes to be jointed.


6.5.4 Cutting Pipes (a) Pipes for drainage works shall be cut and the ends shall be prepared in accordance

with the manufacturers' recommendations; purpose-made equipment recommended by the manufacturer and reviewed without objection by the Project Manager shall be used for cutting the pipes.

(b) Cut ends of pipes shall be square or cut to the correct angle and without damage to the

pipe or coating. Cut ends shall be trimmed and chamfered to suit the type of joint and in such a manner that elastomeric joint rings will not be damaged by the cut end.

(c) Pipes requiring to be cut to form closing lengths shall not be cut until adjacent pipes

have been laid and jointed and the length to be cut can be accurately measured.

(d) Reinforcement in precast concrete pipes which are cut shall be cut back flush with the concrete and protected with epoxy resin.

(e) Pipes which terminate at the inside face of structures shall be cut such that the end of

the pipe is flush with the face.

6.5.5 Jointing Pipes (a) General:

(i) Pipes for drainage works shall be jointed in accordance with the manufacturers' recommendations and using jointing equipment and jointing materials recommended by the manufacturer and reviewed without objection by the Project Manager.

(ii) The Contractor shall inspect pipes, joints, fittings and valves, including internal

and external coatings, immediately before and after jointing. Deleterious material shall be removed and damage shall be repaired immediately before and after jointing. Surfaces which are to be jointed and jointing materials shall be cleaned immediately before jointing. Pipes shall be cleaned out with clean water.

(iii) All joints in pipelines shall be watertight.

(iv) The widths of gaps at joints shall be in accordance with the manufacturers'

recommendations and shall be achieved by marking the outside of the pipe by using metal feelers. The position of elastomeric joint rings shall be checked by using metal feelers after jointing.

(v) Gaps at joints in pipes shall be protected after jointing, by methods reviewed

without objection by the Project Manager, to prevent dirt, stones or other material entering the joint.

(b) Flanged joints:

(i) Flanged joints in pipes for drainage works shall be provided as stated in Clause 6.5.5(b)(ii).


(ii) Bolt holes in flanged joints shall be orientated symmetrically about the vertical diameter with no bolt holes on the vertical diameter. Elastomeric joint rings shall be the correct size and shall not protrude into the bore of the pipe. The rings may be temporarily fixed to the face of the flange using a minimum amount of adhesive of a type recommended by the manufacturer; jointing compound or paste shall not be used for this purpose.

(c) Flexible collar joints:

(i) Flexible collar joints in pipes for drainage works shall be provided as stated in Clause 6.5.5(c)(ii) to (iv).

(ii) The elastomeric joint rings shall be placed in position inside the grooves of the

sleeve. The ends of the pipes shall be well smeared with lubricant over a distance of at least 100 mm from the end of the pipe.

(iii) The sleeve shall be placed on the end of the laid pipe and pushed home to the

location mark on the pipe. The location mark shall be at a distance of half the length of the sleeve minus 3 mm from the end of the pipe unless otherwise recommended by the manufacturer.

(iv) The pipe which is to be jointed to the laid pipe shall be placed in the sleeve and

pushed home to the location mark on the pipe. (d) Push-in joints:

Push-in joints in pipes for drainage works shall be made by smearing the elastomeric joint ring with lubricant and placing the ring in position on the spigot end of the pipe. The spigot shall be placed in the socket of the laid pipe and pushed home.

(e) Detachable joints:

(i) Detachable joints in pipes for drainage works shall be jointed as stated in Clause 6.5.5(e)(ii) and (iii).

(ii) Both CI flanges, the elastomeric joint rings and the central collar shall be

placed over the ends of the pipes before the pipes are placed to the required line and level; a gap of between 5 mm and 6 mm shall be left between the ends of the pipes.

(iii) The flanges, elastomeric joint rings and central collar shall be moved into

position at the ends of the pipes; the central collar shall be positioned centrally over the gap between the ends of the pipe before the bolts are tightened.

(f) Flange adapters:

Joints with flange adapters in pipes for drainage works shall be made by placing the flange adaptor on the plain end before the bolts are tightened.


(g) Solvent welded joints:

Solvent welded joints in pipes for drainage works shall be made by applying solvent cement to the pipes to be jointed and pushing the pipes home. Surplus solvent shall be removed after jointing. Solvent welded pipes jointed outside the trench shall not be placed in the trench until the solvent setting period recommended by the manufacturer has elapsed. In addition, any material or thing contaminated by the solvent shall not be left in the pipe or trench.

(h) Screw joints:

(i) Screw joints in pipes for drainage works shall be made using a threaded coupler. The threaded surfaces of the pipes and coupler shall be cleaned and the threads shall be painted with two coats of bituminous paint. The pipe thread shall be wrapped with three turns of spun yarn and the joint tightened using purpose made tools. Coal tar compounds or white lead paint shall not be used. Locking nuts to branch connections shall be tightened. Branch connections shall not protrude inside the pipe.

(ii) Cast iron pipes shall be laid and bedded one at a time. Each cast iron pipe

should bear evenly on it’s bed. Joint holes shall be cut in the foundation for the purpose of making joints. The spigot of each pipe shall fit easily into the socket of the preceding pipe without any jamming or twisting and shall be pushed well home so that the inverts of the socket and spigot when joined shall be level. Joint gaskets shall be formed with about 2 turns of yarn caulked tightly to the bottom of the socket, a depth of at least 50 mm being left in the socket for lead jointing, which shall be run in molten and caulked into the edge of the socket. Proprietary joints may be proposed for review without objection by the Project Manager.

6.5.6 Protection of Joints

(a) Flanged joints, detachable couplings and flange adapters on buried pipes for drainage

works shall be protected as stated in Clause 6.5.6(b) to (d).

(b) The joint, including bolts and nuts, shall be cleaned to remove all moisture, dust, oil, grease and deleterious material. Bolts and nuts shall be painted with two coats of bituminous paint and the joint shall be coated with primer. Mastic filler shall be applied in such a manner that all depressions, corners and voids between the bolts and nuts are filled and a smooth surface is available on which to apply the anticorrosion tape.

(c) At least two layers anticorrosion tape shall be applied to all parts of the joint and to

the adjacent pipe for at least 200 mm beyond each end of the joint. The tape shall be applied in accordance with the manufacturer's recommendations and shall be wrapped spirally around the joint and pipe with at least 55% overlap per spiral.

(d) The tape shall be moulded manually after application to take up the contours of the

parts being protected.

6.5.7 Repairs to Coatings and Linings Damage to coatings and linings of pipes for drainage works shall not be repaired unless permitted by the Project Manager. If permitted, repairs shall be carried out using materials recommended by the manufacturer and reviewed without objection by the Project Manager.


6.5.8 Thrust and Anchor Blocks (a) Thrust or anchor blocks shall be used to resist forces at bends, branches and stopends

in pressure pipelines for drainage works except where self anchoring joints are used. Concrete for thrust and anchor blocks shall be Grade 20.

(b) The bearing face, and other faces stated in the Contract, of concrete anchor and thrust

blocks shall be cast directly against undisturbed ground; the faces of excavations shall be trimmed to remove loose material before concreting. Excavation required for the block beyond the trench width shall be carried out after the pipe or fitting has been jointed. Excess excavation beyond the face at the block shall be filled with concrete of the same grade as the block.

(c) Internal pressure shall not be applied to the pipeline until thrust and anchor blocks

have developed the specified grade strength.

6.5.9 Bed, Haunch and Surround

(a) Granular bed:

(i) Granular bed to pipelines for drainage works shall be constructed as stated in Clause 6.5.9(a)(ii) to (iv).

(ii) Aggregates for granular bed shall be deposited in the trench in layers not

exceeding 150 mm thick and for the complete width of the trench. Each layer shall be compacted using a plate vibrator or by other methods reviewed without objection by the Project Manager.

(iii) Holes shall be dug in the granular bed to prevent pipes resting on the sockets

and to allow the pipes to be jointed. The pipes shall be laid directly on the granular bed; temporary supports shall not be used.

(iv) After the pipes have been jointed, aggregate shall be deposited in layers not

exceeding 150 mm thick equally on both sides of the pipe to the specified level for the complete width of the trench. Each layer shall be compacted using a plate vibrator.

(b) Concrete bed, haunch and surround:

(i) Concrete bed, haunch and surround to pipelines for drainage works shall be

constructed as stated in Clause 6.5.9(b)(ii) to (vii).

(ii) Concrete for concrete bed, haunch and surround shall be Grade 20.

(iii) Polyethylene sheeting or a blinding layer shall be placed on the trench bottom before concreting.

(iv) Pipes shall be supported at the required level by Grade 20 precast concrete

wedges, blocks or cradles. One support shall be placed adjacent to each end of each pipe and the spacing between supports shall not exceed 3 m. Compressible sheeting shall be placed between the pipes and supports.

(v) Flexible joints shall be formed in concrete bed, haunch and surround at flexible

joints in pipelines. Joint filler shall be placed next to the flexible joint in the pipeline and shall extend for the complete thickness of the bed, haunch and surround.


(vi) Concrete shall be placed evenly over the complete width of the bed and over the complete length of the pipe being concreted up to a level of 25 mm below the underside of the pipe. Concrete shall then be placed on one side of the pipe only and worked under the pipe until the concrete spreads under the pipe. Concrete shall then be placed equally on both sides of the pipe to the specified level.

(vii) Pipes for drainage works which are 1 m or less below the surface of a

carriageway shall be protected with Grade 20 concrete surround.

(viii) The aggregate for Grade 20 concrete stated in Clause 6.5.9(b)(i) to (vii) shall be natural stone, crushed rock or crushed concrete. Such Grade 20 concrete shall have the following minimum cementitous content:

Exposure condition Minimum cememtitous content (kg/m3) Moderate 280 Severe 330

(c) Fill material surround:

(i) Fill material surround to pipelines for drainage works shall be deposited and compacted as stated in Clauses 7.4.34 and 7.4.35.

(ii) Fill material surround to underfloor drainage pipes and perforated perimeter

drain pipes shall be uniform, clean and free draining granular material with less than 5% passing 63 m.

(d) Installation of drainage pipe support in structures:

(i) The locations of the brackets shall be determined by the Contractor and arranged to satisfy the following requirements:

- the maximum permitted spacing between brackets for pipe support indicated

on the Employer’s Drawings shall not exceeded; - minor reductions in the maximum permitted spacing may be made to avoid

clamps coinciding with pipe joints; and - a clear distance of at least 50 mm shall be maintained between socket

fixings and adjacent reinforcing bars or tendons.

(ii) The interface between the brackets and the concrete shall be protected by an inert layer of corrosion resisting tape reviewed without objection by the Project Manager.

6.5.10 Tolerances

(a) Tolerances: pipelines drainage works:

(i) Except as stated in Clause 6.5.10(a)(ii), pipelines for drainage works shall comply with the following requirements: - the line of gravity pipelines shall be within 20 mm of the specified line; - the invert level of gravity pipelines shall be within 6 mm of the specified

invert level and there shall be no backfall at any point; - the line of pressure pipelines shall be within 50 mm of the specified line;

and - the invert level of pressure pipelines shall be within 20 mm of the specified

invert level.


(ii) Termination pipes in pipelines for drainage works which are designed to connect to pipes or fittings laid by others shall comply with the following requirements: - the position of the centre of the termination face of the pipe in the

longitudinal direction shall be within 10 mm of the specified position; - the position of the centre of the termination face of the pipe in the lateral

direction shall be within 3 mm of the specified position; - the gradient of the termination pipe shall be within 0.5° of the specified

gradient; and - the invert level at the termination face of the pipe shall be within 3 mm of

the specified invert level.

6.5.11 Connections (a) Connections to structures:

(i) The joints between pipes for drainage works and structures into which the pipes are built shall be watertight; protective coatings shall be removed over the length to be built in before the pipe is built in. Pipe collars and sockets shall not be built in to structures.

(ii) Two flexible joints shall be provided in pipelines adjacent to the outside faces

of structures into which pipes will be built. The distances from the outside face of the structure to the first joint and from the first joint to the second joint shall be as stated in Table 6.10.

(iii) The ends of pipes which are built in to structures shall be temporarily sealed

with a blank flange, brickwork or timber boarding. The temporary seals shall be left in position until the Project Manager permits their removal.

Table 6.10: Flexible Joints at Structures

Position of first flexible joint from structure Diameter of pipe

Minimum Maximum

Distance of second

flexible joint from

first flexible joint

not exceeding 450 mm 450 mm - 800 mm

exceeding 450 mm

but not exceeding

1050 mm

900 mm - 1200 mm

exceeding 1050 mm

150 mm 500 mm or

diameter of pipe, which-ever is less

1500 mm - 1800 mm

(b) Connections to pipes:

(i) Pipe saddles shall be connected to concrete or vitrified clay pipes by bedding the saddle on a cement mortar bed and forming a cement mortar fillet to provide at least 50 mm cover to the base of the saddle. Cement mortar shall consist of cement and sand in the proportions 1:3 by mass.

(ii) UPVC pipe saddles shall be fixed to UPVC pipes using a purpose-made

mechanical clip or solvent cement of a type recommended by the manufacturer and reviewed without objection by the Project Manager.


(iii) Branch pipelines shall be connected to main pipelines using Y-junctions of the same type and strength as the stronger of the pipes being jointed. The angle of the Y-junction shall be such that the angle between the direction of flow in the branch and main pipes shall be between 30 and 45.

(iv) Pipes which are to be connected to concrete or clay pipes without a Y-junction

or purpose made pipe saddle shall be cut on a splay to form a junction such that the angle between the direction of flow in the main pipe and the incoming pipe is between 30 and 60. The hole which is cut in the main pipe to which a connection is to be made shall be of a suitable elliptical shape to suit the cut end of the branch pipe. The length of the branch pipe shall be such that: - the cut end of the pipe rests on the outside barrel of the main pipe; - the cut pipe does not project inside the main pipe; and - the joint between the cut pipe and the main pipe shall be sealed externally

and sealed internally flush with the main pipe with cement mortar. Cement mortar shall consist of cement and sand in the proportions 1:3 by mass.

(v) The positions of the pipe junctions relative to the manhole or structure

immediately downstream shall be measured and recorded before backfilling.

(vi) The ends of connecting pipes not required for immediate use shall be sealed with a blank flange or brickwork and the position measured and recorded before backfilling.

(vii) The Contractor shall allow for the existing flow of water when connecting new

sewers, drains and culverts to existing pipelines, culverts, manholes and other drainage chambers.

(viii) Prior to the connection to existing pipelines, culverts, manholes and other

drainage chambers the Contractor shall check the invert level of the existing drainage to which he has to connect and inform the Project Manager of any discrepancies between the actual level and the level specified on the Employer’s Drawings.

6.5.12 Manholes, Chambers, Gullies and Channels

(a) Manholes, chambers and gullies:

(i) Bases, inverts and benching for precast concrete manholes shall be constructed in-situ using Grade 20 concrete, unless otherwise stated in the Contract.

(ii) Precast concrete units for manholes and chambers shall be set vertically with

step irons staggered and vertically aligned above each other. Joints between precast units shall be the rebated type and shall be sealed with cement mortar; lifting holes shall be filled with cement mortar. Surplus cement mortar shall be removed and joints shall be pointed.

(iii) Concrete surrounds to manholes, chambers and gullies shall be Grade 20

concrete. Joints in concrete surrounds shall be staggered by at least 150 mm from joints in the precast units. Concrete surrounds to gullies shall be placed up to the sides of the excavation.

(iv) The frames for manhole covers and gully gratings shall be set to the same

levels as the surrounding surface, allowing for falls and cambers, using brickwork and/or concrete. The number of courses of brickwork used below frames shall not exceed three and the minimum grade for concrete shall be Grade 20.


(v) Cement mortar for fixing manhole covers and gully gratings in position and bonding brickwork shall consist of cement and sand in the proportions 1:3 by mass.

(vi) Excavations around manholes and chambers in carriageways shall be filled

using Grade 10 concrete up to the carriageway formation level. Fill material for excavations around other manholes and chambers shall be fine fill material.

(vii) Manholes, chambers and gullies shall be water tight on completion.

(b) Concrete open channels:

The top surfaces of side walls of concrete open channels shall be constructed to the same levels as the adjoining Permanent Works. Excess excavation beyond the channel walls shall be filled with Grade 10 concrete.

6.5.13 Marker Blocks

(a) The ends of pipes which do not terminate at a manhole, chamber, gully or structure

shall be marked with marker blocks. The blocks shall be 150 mm x 150 mm x 150 mm and shall be constructed using Grade 20 concrete.

(b) A wire shall be connected from a hook at the underside of the block to the plug at the

end of pipes.

(c) Marker blocks shall be set flush level with the adjacent Permanent Works and shall have the letters ‘CD’ marked on the upper surface.

6.5.14 Installation of Penstocks and Valves

(a) Penstocks and valves shall be installed in accordance with the manufacturer's

recommendations and in the closed position.

(b) Frames for penstocks shall be fixed in position leaving a 20 mm gap between the frame and the concrete surface. Contact between the penstock door and frame shall be checked using a feeler gauge 0.1 mm thick or other size recommended by the manufacturer.

(c) Box-outs and rebates for penstock and valve frames and gaps between frames and

concrete surfaces shall be filled with cement mortar. (d) After installation, penstocks and valves shall be cleaned and moving parts shall be

lightly greased and checked for ease of operation. Penstocks and valves shall be left in a closed position.

6.5.15 Pipes and Manholes to be Abandoned

(a) Manholes, chambers and gullies which are to be abandoned shall be demolished and

removed unless otherwise stated in the Contract. Abandoned pipes, culverts, manholes, chambers and gullies shall be filled with foam concrete or grout, by pumping or by gravity. The lowest point of abandoned pipelines shall be sealed with concrete or bricks. Filling shall start from the lowest point and shall continue until all voids are completely filled.


(b) If the top of a pipe or culvert, or the bottom of a manhole, chamber or gully to be abandoned is 1 m or less below the finished ground level, the pipe, manhole, chamber or gully shall be removed and disposed of by the Contractor. The void shall be filled with foam concrete, granular fill material or special fill material which has been reviewed without objection by the Project Manager.

(c) If the top of a pipe or culvert, or the bottom of a manhole, chamber or gully to be

abandoned is more than 1 m below the finished ground level, the pipe, culvert, manhole, chamber or gully shall be filled with foam concrete or grout as stated in Clause 6.3.25.

6.5.16 Cleaning of Pipelines

(a) Pipelines for drainage works shall be cleaned by pigging or by high pressure water

jetting; manholes and chambers shall be cleaned and washed. Cleaning shall be carried out:

(i) before and after the complete pipeline, or parts of the pipeline if permitted by

the Project Manager, have been tested; (ii) after the Temporary Works required for testing have been removed; and (iii) after parts of the pipeline removed for testing have been reconnected.

(b) Pipelines shall be cleaned not more than 7 days before the application for Completion

Certificate for the pipeline works is submitted.

6.6 INSPECTION, TESTING AND COMMISSIONING

6.6.1 Testing of Pipelines (a) Inspection of pipelines

The cleanliness, bore, linearity and joints of pipelines of 450 mm diameter or less shall be checked by pulling a mandrel through the completed pipeline, or parts of the pipeline if permitted by the Project Manager, after cleaning. The mandrel shall be 750 mm long and 12 mm less in diameter than the nominal diameter of the pipe.

(b) Inspection of pipelines by CCTV

All pipelines of 450mm diameter or less not inspected in accordance with Clause 6.6.1(a) shall be inspected internally by CCTV after cleaning in accordance with Clause 6.5.16. The procedure for internal inspection by CCTV shall be as stated in Appendix A6.1. The defects discovered by the CCTV inspection shall be rectified in accordance with Clause 6.6.8(b).

6.6.2 Testing of Pipes for Drainage Works

(a) Batch: pipes for drainage works

A batch of pipes or fittings for drainage works is any quantity of pipes or fittings of the same type and nominal diameter, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.


(b) Samples: pipes for drainage works

One sample of pipe for drainage works and each type of fitting shall be provided from each 50 pipes or fittings or part thereof in a batch.

(c) Testing: pipes for drainage works

(i) Each sample of pipes and fittings for drainage works shall be tested in accordance with the relevant British Standard.

(ii) The method of testing shall be in accordance with the following:

Concrete pipes and fittings : BS 5911: Part 100 Vitrified clay pipes, fittings and joints : BS 65 Ductile iron pipes and fittings : BS 4772 Grey iron pipes and fittings : BS 4622 UPVC pipes for industrial purposes : BS 3506 UPVC soil and ventilating pipes, fittings and accessories : BS 4514 UPVC rainwater goods : BS 4576:Part 1 UPVC underground drain pipes and fittings : BS 4660 Plastic waste pipes and fittings : BS 5255 UPVC pipes and fittings for gravity sewers : BS 5481

(d) Non-compliance: pipes for drainage works

(i) If the result of any test required in accordance with the relevant British Standard for pipes and fittings for drainage works does not comply with the specified requirements for the test, one additional sample shall be provided from the same batch and additional tests for the property shall be carried out.

(ii) The batch shall be considered as not complying with the specified requirements

for the property if the result of any additional test does not comply with the specified requirements for the property.

6.6.3 Testing of Aggregates for Granular Bed

(a) Batch: aggregates for granular bed

A batch of aggregates for granular bed is any quantity of aggregates for granular bed of the same type, produced at the same time in the same place, covered by the same certificates and delivered to the Site at any one time.


(b) Samples: aggregates for granular bed

(i) One sample of aggregates for granular bed shall be provided from each batch of aggregates for granular bed delivered to the Site.

(ii) The size of each sample shall be 40 kg.

(iii) The method of sampling shall be in accordance with BS 812: Part 102.

(iv) The moisture content of the sample shall be representative of the moisture

content of the material in the batch. (c) Testing: aggregates for granular bed

Each sample of aggregates for granular shall be tested to determine the particle size distribution and ten percent fines value in accordance with BS 812:Part 103 and BS 812:Part 111, and the compaction fraction value in accordance with Appendix A6.2.

(d) Compliance criteria: compaction fraction value

The results of tests for compaction fraction value of aggregates for granular bed shall comply with the following requirements:

(i) The compaction fraction value for pipe bed not exceeding 300 mm nominal

diameter shall not exceed 0.3; and

(ii) The compaction fraction value for pipe bed exceeding 300 mm nominal diameter shall not exceed 0.15.

6.6.4 Testing of Precast Concrete Units for Manholes, Chambers and Gullies

(a) Batch: manholes, chambers and gullies

A batch of precast concrete units for manholes, chambers or gullies is any quantity of precast concrete units for manholes, chambers or gullies of the same type and size, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: manholes, chambers and gullies

One sample of precast units for manholes, chambers or gullies shall be provided from each batch of 50 precast concrete units for manholes, chambers or gullies or part thereof delivered to the Site.

(c) Testing: manholes, chambers and gullies

(i) Each sample of precast concrete units for manholes, chambers or gullies shall be tested in accordance with the relevant British Standard.


Precast concrete units for manholes : BS 5911: Part 200 Inspection chambers and gullies : BS 5911: Part 2.


(d) Non-compliance: manholes, chambers and gullies

(i) If the result of any test required in accordance with the relevant British Standard for precast concrete units for manholes, chambers or gullies does not comply with the specified requirements for the test, one additional sample shall be provided from the same batch and additional tests for the property shall be carried out.

(ii) The batch shall be considered as not complying with the specified requirements

for the property if the result of any additional test does not comply with the specified requirements for the property.

6.6.5 Testing of Manhole Covers, Gully Gratings and Kerb Overflow Weirs

(a) Batch: covers, gratings and weirs

A batch of manhole covers, gully gratings or kerb overflow weirs is any quantity of covers, gratings or weirs of the same type, manufactured by the same manufacturer, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: covers, gratings and weirs

One sample of manhole covers, gully gratings or kerb overflow weirs shall be provided from each batch of 20 covers, gratings or weirs or part thereof delivered to Site.

(c) Testing: covers, gratings and weirs

(i) Each sample of manhole covers, gully gratings or kerb overflow weirs shall be weighed to determine the mass, a load test shall be carried out on each sample of covering and grating to determine the resistance to fracture.

(ii) The method of testing shall be as stated in Appendix A6.3. The test loads shall

be as stated in Table 6.6 and Table 6.7. (d) Compliance criterion: resistance to fracture of covers and gratings

Manhole covers and gully gratings shall withstand the test load without fracture or cracking.

(e) Non-compliance: mass of covers, gratings and weirs

(i) If the result of any test for mass of any manhole cover, gully grating or kerb overflow weir does not comply with the specified requirements for mass, every cover, grating and frame in the batch shall be weighed to determine its mass.

(ii) If any cover, grating or weir does not comply with the specified requirements

for mass, it shall not be used in the Permanent Works. (f) Non-compliance: resistance to fracture of covers and gratings

(i) If any manhole cover or gully grating does not comply with the specified requirements for resistance to fracture, two additional samples shall be provided from the same batch and tested to determine their resistance to fracture.


(ii) The batch shall be considered as not complying with the specified requirements for resistance to fracture if the result of either additional test does not comply with the specified requirements for resistance to fracture.

6.6.6 Testing of Watertightness of Penstocks

(a) Testing: watertightness of penstocks

(i) Penstocks shall be tested for watertightness after installation by applying pressure using a head of water applied to one face of the penstock and no head of water on the other face. The test pressure and the face on which the pressure is to be applied shall be as stated in the Contract.

(ii) The method of testing shall be as submitted for review by the Project Manager.

(iii) The test pressure shall be maintained for 24 hours.

(b) Compliance criteria: watertightness of penstocks

The results of tests for watertightness of penstocks shall comply with the following requirements:

(i) there shall be no leaks through the penstock during the test; and

(ii) there shall be no leaks or damp patches visible at the joint between the penstock

and the structure during the test. (c) Non-compliance: watertightness of penstocks

If the result of any test for watertightness of penstocks does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the penstock shall be re-tested.

6.6.7 Testing of Gravity Pipelines for Drainage Works

(a) Gravity pipelines for drainage works shall be tested as stated in Clause 6.6.7.(b) to

(h).

(b) Gravity pipelines for sewage shall be tested by the methods stated in Table 6.11 at the following times:

(i) after the pipes have been jointed and the bedding has been placed and

immediately before haunch or surround is placed or fill material is deposited;

(ii) after haunch and surround has been placed and fill material has been deposited and compacted; and

(iii) not more than 7 days before a Completion Certificate for the pipeline works is

applied for.


(c) Gravity pipelines for surface water shall be tested by the methods stated in Table 6.11 at the following times:

(i) after the pipes have been jointed and the bedding has been placed and

immediately before haunch or surround is placed or fill material is deposited; and

(ii) after haunch and surround has been placed and fill material has been deposited

and compacted. (d) Water tests and air tests on pipelines shall be carried out on the complete pipeline

between manholes, chambers and structures; pipelines shall not be tested in parts unless the specified test pressure will be exceeded. Short branch pipelines shall be tested with the main pipeline and long branch pipelines shall be tested separately.

(e) Infiltration tests shall be carried out on the complete pipeline between manholes,

chambers and structures, including manholes, chambers and branches within the pipeline system.

(f) The method of testing shall be in accordance with Appendix A6.4. (g) Visual inspections shall be carried out on the complete pipeline between manholes,

chambers and structures. (h) Visual inspections shall be carried out by the Contractor in the presence of the Project

Manager. Table 6.11: Testing Gravity Pipelines

Type of pipeline

Diameter of pipeline

Time of test

Method of testing

Sewage not exceeding as Clause 6.6.7(b)(i) Water test or air test

900 mm as Clause 6.6.7(b)(ii) Water test or air test

as Clause 6.6.7(b)(iii) Infiltration test

Sewage exceeding as Clause 6.6.7(b)(i) Visual inspection

900 mm as Clause 6.6.7(b)(ii) Water test or air test

as Clause6.6.7(b)(iii) Infiltration test

Surface not exceeding as Clause 6.6.7(c)(i) water 900 mm Or

as Clause 6.6.7(c)(ii) Water test or air test

Surface exceeding As Clause 6.6.7(c)(i) Visual inspection

water 900 mm as Clause 6.6.7(c)(ii) Water test or air test

6.6.8 Compliance criteria: gravity pipelines for drainage works (a) The results of tests on gravity pipelines for drainage works shall comply with the

following requirements:

(i) the leakage of water from the pipeline determined by the water test shall not exceed the permitted leakage calculated in accordance with Clause A6.4.8 of Appendix A6.4;


(ii) there shall be no discernable leakage from the pipe or from any joint during the water test;

(iii) the air pressure shall remain above 75 mm head of water at the end of the air

test; and

(iv) there shall be no infiltration or damage to pipes or joints as determined by the visual inspection.

(b) The Contractor shall investigate the reason for any non compliance. Remedial or

replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be re-tested.

6.6.9 Testing of pressure pipelines for drainage works

(a) Pressure pipelines for drainage works shall be tested as stated in Clause 6.6.9(b) to

(g).

(b) The pipeline shall be tested at the following times:

(i) after the pipes have been jointed and the bedding has been placed and immediately before haunch or surround is placed or fill material is deposited; and

(ii) after haunch and surround has been placed and fill material has been deposited

and compacted for the complete pipeline.

(c) The test stated in Clause 6.6.9(b)(i) shall not be carried out on parts of a pipeline unless permitted by the Project Manager. The test stated in Clause 6.6.9(b)(ii) shall be carried out on the complete pipeline.

(d) The test pressure shall be as stated in the Contract. If the test pressure is not stated in

the Contract, the test pressure shall be 1.5 times the maximum working pressure in the part of the pipeline tested.

(e) Tests shall not be carried out simultaneously on more than one pipeline in the same trench.

(f) The method of testing shall be in accordance with Appendix A6.5.

(g) Testing of pressure pipelines by means of tests on individual joints shall not be carried out instead of tests stated in Clause 6.6.9(b) to (f).

6.6.10 Compliance criteria: pressure pipelines for drainage works

(a) The results of tests on pressure pipelines for drainage works shall comply with the

following requirements:

(i) The leakage of water from the pipeline determined by the pressure test shall not exceed the permitted leakage calculated in accordance with Clause A6.5.4 of Appendix A6.5.

(ii) There shall be no discernable leakage of water from the pipeline or from any

joint during the pressure test.


(b) If the result of any test on pressure pipelines for drainage works does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be re-tested.


APPENDIX A6.1

CCTV INSPECTION OF PIPELINES A6.1.1 Scope

This method covers the internal inspection of pipelines by means of closed circuit television. (CCTV)

A6.1.2 Equipment (1) The equipment specified in Clauses A6.1.2(l) (a) to (g) shall be provided:

(a) A CCTV colour camera with integral lighting unit. The camera shall be a type designed and constructed for the specified purpose and shall be capable of operating in 100% relative humidity. The camera shall be fitted with a rotating mirror for complete circumferential viewing. The system shall be capable of producing a clear and high quality picture of the entire periphery of the pipe on the monitor screen and recording tape. The camera and lighting unit shall be mounted on a self-propelled crawler or on skids linked to a manual or power operated winch.

(b) A monitor screen which displays the camera view during the inspection. The

monitor screen shall be housed in covered accommodation with facilities for inspection by the Project Manager and others.

(c) A screen writer which displays on the monitor screen details of the inspection

including date, location, pipe material, diameter of pipe, direction of view and comments on the condition of the pipe.

(d) A linear measuring device which displays the chainage of the camera position

automatically on the monitor screen. The device shall be capable of measuring the chainage to within an accuracy of 0.1% of the length of the pipeline or ±0.3 m whichever is the greater.

(e) A control unit which controls camera movement, lighting intensity, focusing

and recording by a video system. (f) A VHS video recording system to record the inspection and information

displayed on the monitor screen.

(g) A 35 mm single lens reflex (SLR) camera capable of producing photographs with details of the date.


A6.1.3 Procedure (1) The procedure shall be as specified in Clause A6.1.3 (1) (a) – (d)

(a) The camera shall be moved through the pipeline in the direction directed by the Project Manager at a speed not exceeding 0.15 m/s. If the camera cannot pass through the complete pipeline in one operation, the inspection shall be carried out from both ends of the pipeline.

(b) The camera shall be stopped whenever directed by the Project Manager to

allow inspection by the Project Manager. (c) The video system shall be operated during the complete inspection to provide a

continuous record of the inspection and information on the monitor screen. (d) Photographs of the monitor screen shall be taken whenever required by the

Project Manager.

A6.1.4 Recording of Results

(1) Records of the inspections shall be kept by the Contractor on the Site and a report shall be submitted to the Project Manager for review within 14 days of completion of the inspection. The report shall contain the following details:

(a) key map showing pipelines inspected and associated manholes, chambers and

structures, (b) tables listing details of inspection, including date, location, pipe material,

diameter of pipe, chainage, manholes, junctions and other features and the condition of pipes and joints; the condition of pipes and joints shall be illustrated by a coding systems in accordance with the `Manual of Sewer Condition Classification' (1980) published by the U.K. National Water Council, and

(c) a summary showing the number and type of defects in each pipeline inspected.

(2) The following items shall be submitted at the same time as the report:

(a) video film providing a continuous record of the inspection and information on the monitor screen together with an index showing the location on the video tape of commencement of each pipe inspection; and

(b) photographs of the monitor screen including date and chainage; the

photographs shall be 3R size and shall be mounted in photograph albums.


APPENDIX A6.2

DETERMINATION OF THE COMPACTION FRACTION VALUE OF AGGREGATES FOR GRANULAR BED

A6.2.1 Scope

This method covers the determination of the compaction fraction value of aggregates for granular bed.

A6.2.2 Apparatus

The following equipment shall be provided:

(1) a steel open-ended cylinder, 150 mm internal diameter by 250 mm high, with a wall thickness of not less than 3.5 mm;

(2) a steel rammer of 40 mm diameter weighing approximately 1 kg; and (3) a steel rule calibrated to 1 mm.

A6.2.3 Procedure

(1) The procedure shall be as described in Clauses A6.2.5 (1) (a) – (e)

(a) The sample shall be placed on a clean surface and shall be divided by quartering or by using a riffle box to obtain a specimen weighing approximately 10 kg.

(b) The cylinder shall be placed on a firm level surface and shall be filled without

tamping with material taken from the sample. Surplus material shall be struck off level with the top of the cylinder, and cleared from the area around the cylinder.

(c) The cylinder shall be lifted clear of the contents and placed alongside the

material. (d) Approximately one quarter of the material shall be placed in the cylinder and

compacted using the rammer until no further compaction can be achieved. The procedure shall be repeated for each of the remaining three quarters of the material. The top surface shall be compacted as level as practicable.

(e) The distance (d) from the top of the cylinder to the top surface of the material

shall be measured to the nearest 1 mm. A6.2.4 Calculation

The compaction fraction value of the material shall be calculated from the equation: Compaction fraction value = d/h where: - d is the distance from the top of the cylinder to the top surface of the material (mm), - h is the height of the cylinder (mm).


A6.2.5 Reporting of Results

The following shall be included in the report submitted to the Project Manager:

(1) identification of sample; (2) compaction fraction value to the nearest 0.01; (3) source and type of material; (4) date of test; and (5) statement that the test method used was in accordance with this General Materials and

Workmanship Specification.


APPENDIX A6.3

DETERMINATION OF THE RESISTANCE TO FRACTURE OF MANHOLE COVERS AND GULLY GRATINGS

A6.3.1 Scope

This method covers the determination of the resistance to fracture of manhole covers and gully gratings by means of a load test.

A6.3.2 Equipment


(1) manufacturer's recommended test frame for the manhole cover or gully grating or a fabricated test frame of a type reviewed without objection by the Project Manager which will simulate the normal conditions of use of the cover or grating;

(2) circular hardwood bearing block faced with hard rubber or other resilient material.

The diameter of the block shall be as stated in Table 6.6 or Table 6.7 for the relevant cover or grating. The block shall be sufficiently rigid to ensure that the load is equally distributed over the whole area of the block;

(3) test loads; and (4) equipment for measuring the loads applied, readable and accurate to 0.05 t or 2% of

the specified test load, whichever is greater. A6.3.3 Procedure

The procedure shall be as follows:

(1) the full bearing area of the frame shall be rigidly supported; (2) the cover or grating shall be placed in the frame. The bearing block shall be placed

centrally on the cover or grating; (3) the specified test load as stated in Table 6.6 and 6.7 shall be applied without shock;

and (4) the specified test load shall be maintained for at least 30 seconds and removed.

A6.3.4 Reporting of Results The following shall be induced in the report submitted to the Project Manager:

(1) identification of sample; (2) the load applied, to the nearest 0.05 t or 2% of the specified test load, whichever is

greater; (3) details of any fracture or cracks; and (4) statement that the test method used was in accordance with this General Materials and



APPENDIX A6.4

TESTS ON GRAVITY PIPELINES FOR DRAINAGE WORKS

A6.4.1 Scope This method covers water tests, air tests, visual inspections and infiltration tests on gravity

pipelines for drainage works. A6.4.2 Equipment The following equipment shall be provided:

(1) expanding disc stoppers or air bags for sealing pipes; (2) struts and wedges; (3) force pump for water test; (4) standpipe for water test; (5) measuring vessel for water test, readable and accurate to 0.01 litre; (6) U-tube for air test; and (7) trolleys to obtain access inside pipelines for visual inspections. Mechanical fans shall

be provided to ensure that an adequate air supply is available; internal combustion engine driven fans shall be fitted with a flexible exhaust or other methods of keeping exhaust fumes clear of the fresh air intake.

A6.4.3 Procedure: before Tests and Inspections The procedure before tests and inspections shall be as follows:

(1) debris and water shall be removed from the pipeline; and (2) openings to the pipeline shall be sealed using expanding disc stoppers or air bags and

the seals secured against movement. A6.4.4 Procedure: Water Test The procedure for the water test shall be as follows:

(1) the pipeline shall be filled with water and shall be kept filled for two hours before testing starts to allow absorption to take place;

(2) test pressure of 1.2 m head of water above the soffit of the pipe at the high end shall

be applied at the standpipe and maintained for 30 minutes; the test pressure applied shall not exceed 6 m head of water at the invert of the low end of the pipe;

(3) the head of water at the standpipe shall be topped up at 5 minute intervals during the

test, and shall be filled to the specified head at the end of the test period; the amounts of water added to the standpipe shall be measured using the measuring vessel; and

(4) the leakage of water from the pipeline shall be measured as the amount of water added to maintain the specified head of water.


A6.4.5 Procedure: Air Test

The procedure for the air test shall be as follows:

(1) air shall be pumped into the pipeline until a test pressure of slightly more than 100

mm of water is registered on a U-tube manometer connected to the pipeline. Five minutes shall be allowed for stabilisation of the air temperature, and the air pressure shall then be adjusted to 100 mm of water; and

(2) the pressure shall be read from the U-tube at the end of a five-minute period without

further pumping.

A6.4.6 Procedure: Visual Inspection

The inside of the pipeline shall be inspected visually, and infiltration or damage to pipes or joints shall be recorded.

A6.4.7 Procedure: Infiltration Test

The procedure for the infiltration test shall be in accordance with BS 8005: Part 1 Clause

13.6.

A6.4.8 Calculation

The permitted leakage of water from the pipeline during the water test shall be calculated from the equation:

t

Permitted leakage = d x 1 x 60

x P litre

where: - d is the internal diameter of the pipe (m), - l is the length of pipeline tested (m), - t is the test period (min), - P is the average test pressure (m).


The following shall be included in the report submitted to the Project Manager:

(1) nominal internal diameter of the pipe to the nearest 1 mm; (2) location and length of pipeline tested to the nearest 0.3 m; (3) test pressure applied during the water test to the nearest 0.01 m, and during the air test

to the nearest 1 mm head of water; (4) test period to the nearest 1 min; (5) leakage and permitted leakage for the water test to the nearest 0.1 litre; (6) amount of infiltration and permitted amount of infiltration for the infiltration test to

the nearest 0.1 litre;


(7) details of any discernable leakage of water from the pipe or from any joint during the water test; and

(8) statement that the test method used was in accordance with this General Materials and



APPENDIX A6.5

TESTS ON PRESSURE PIPELINES FOR DRAINAGE WORKS

A6.5.1 Scope

This method covers the determination of the leakage of water from pressure pipelines for drainage works by means of a pressure test.

A6.5.2 Equipment


(1) blank flanges or caps; (2) struts and wedges; (3) temporary concrete blocks or other anchors; (4) force pump; (5) pressure gauge, readable and accurate to 0.01 m head of water. The gauge shall be

either a conventional circular type of at least 300 mm diameter or shall be a digital indicator type; and

(6) measuring vessel, readable and accurate to 0.01 litre.

A6.5.3 Procedure


(1) pipes and valves shall be cleaned and the operation of valves shall be checked. Air

valves shall be isolated. (2) blank flanges or caps shall be fixed to the ends of the pipeline, or part of the pipeline,

to be tested. Tests shall not be made against closed valves. (3) the blank flanges and caps and closed valves against which tests are made shall be

secured with struts and wedges against temporary concrete blocks or other anchors. The blocks shall be completed and shall have hardened sufficiently before testing starts. Thrust and anchor blocks, pipe straps and other devices required to prevent movement of pipes and fittings shall be completed before testing starts.

(4) the pipeline shall be filled with water and all air shall be removed; measures shall be

taken during filling to provide free outlets for air and to prevent water hammer. (5) the pressure in the pipeline shall be increased to working pressure and the pipeline

shall remain filled at this pressure for 2 hours to allow absorption to take place and to achieve conditions which are as stable as practicable.

(6) the pressure in the pipeline shall be increased slowly by pumping water into the

pipeline using a force pump until the specified test pressure is reached at the lowest part of the pipeline being tested.


(7) the pressure in the pipeline shall be maintained at the specified test pressure, using the force pump if necessary, for a period of at least 1 hour.

(8) at the end of the 1 hour period the pressure shall be increased, if necessary, to the

specified test pressure and pumps and water supply points shall be disconnected. (9) the pipeline shall be left in this condition for a test period of 1 hour; no water shall be

allowed to enter the pipeline during the test period. (10) at the end of the test period the pressure in the pipeline shall be recorded. (11) the pumps and water supply points shall be reconnected and the pressure shall be

increased to the specified test pressure. (12) water shall be drawn off from the pipeline until the pressure in the pipeline is the

same as at the end of the test period. The leakage of water from the pipeline shall be measured as the amount of water drawn off.

A6.5.4 Calculation

(1) The average test pressure (P) shall be calculated as the average of the specified test Pressure and the pressure at the end of the test period.

(2) The permitted leakage of water from the pipeline during the pressure test shall be

calculated from the equation:

t Permitted leakage = d x 1 x

12 x P litre

where:

- d is the nominal internal diameter of the pipe (m), - l is the length of pipeline tested (km), - t is the test period (hr), - P is the average test pressure (m).

A6.5.5 Reporting of Results The following shall be included in the report submitted to the Project Manager:

(1) the nominal internal diameter of the pipe; (2) the location and length of pipeline tested to the nearest 0.3 m; (3) the test period to the nearest one minute; (4) the specified test pressure to the nearest 0.01 m head of water; (5) the pressure at the end of the test period to the nearest 0.01 m head of water; (6) the average test pressure to the nearest 0.01 m head of water;


(7) leakage and permitted leakage to the nearest 0.1 litre; (8) details of any discernable leakage of water from the pipeline during the test; and (9) that the test method used was in accordance with this General Materials and

Workmanship Specification;


SECTION 7 EARTHWORKS 7.1 DEFINITIONS AND ABBREVIATIONS 7.1.1 Areas of Fill Areas of fill are areas within the Site, including areas in embankments, platforms and slopes

and in excavations for structures, pits and trenches, in which fill material is deposited and compacted as part of the Permanent Works.

7.1.2 Earthworks Final Surface and Formation “Earthworks final surface” is the surface to which the work included in Section 7 is finished.

“Formation” is that part of the earthworks final surface on which a pavement, structure or utility, is constructed, or on which the blinding or bedding for a pavement, structure or utility is placed.

7.1.3 Earthworks Material Earthworks material may consist of soil, rock, crushed concrete or crushed inert demolition

material which is on or below the Site at the commencement of the Contract, or which is imported to the Site to carry out the Works.

7.1.4 Topsoil “Topsoil” shall mean the surface material which contains humus and supports vegetation. 7.1.5 Rock, Boulders and Materials other than Rock “Rock” shall mean all naturally occurring hard strata which would normally be removed by

blasting, by ripping, by chemical, gas or mechanical bursting agents, by hydraulic breaker, by pneumatic drills or by wedges and sledge hammers if removed by hand.

Boulders are isolated volumes of Rock which exceed 0.2m³ and are contained in a matrix of “Material other than Rock”.

“Material other than Rock” shall mean material which cannot be classified as Topsoil or

Rock. 7.1.6 Public Fill Public fill shall mean the inert material arising from construction and demolition activities

such as site clearance, excavation, construction, refurbishment, renovation, demolition and roadworks. Public fill comprises material including stone, rock, masonry, brick, concrete, soil and other inert material. There is no size limitation on the public fill, and a small amount of timber mixed with otherwise suitable material is permissible. The public fill may also consist of wet soil.

7.1.7 Intermediate Areas of fill Intermediate areas of fill are areas of fill which are stated in the Contract as such, and in

which fill material is deposited and compacted directly over shallow water or naturally occurring soft ground.


7.2 MATERIALS 7.2.1 Fill Material

(a) Fill material, other than public fill, shall consist of naturally occurring or processed material which at the time of deposition is capable of being compacted in accordance with the specified requirements to form stable areas of fill.

(b) Fill material shall not contain any of the following:

(i) material susceptible to volume change, including marine mud soil with a liquid limit exceeding 65% or a plasiticity index exceeding 35%, swelling clays and collapsible soils;

(ii) peat, vegetation, timber, organic, soluble or perishable material; (iii) dangerous or toxic material or material susceptible to combustion; (iv) metal, rubber, plastic or synthetic material; (v) material susceptible to volume change, marine mud or material from swamps;

or

(vi) other environmentally unacceptable contaminants.

(c) The different types of fill material shall have the particle size distributions within the ranges stated in Table 7.1.

(d) Special fill material shall consist of material which has a liquid limit not exceeding

45%, a plasticity index not exceeding 20% and a coefficient of uniformity exceeding 50.

(e) Granular fill material shall consist of clean, hard, durable material. (f) Rock fill material shall consist of pieces of hard, durable rock of which not more than

30% by mass is discoloured or shows other evidence of decomposition. Crushed rock or crushed concrete may be permitted subject to review without objection by the Project Manager.

(g) The Contractor will not be permitted to erect a crushing plant under the Contact. (h) The soluble sulphate content of fill material placed within 500 mm of concrete,

cement bound material or cementitious material shall not exceed 1.9 grams of sulphate, expressed as SO3, per litre.

(i) The total sulphate content, expressed as SO3, of fill material placed within 500 mm of

metalwork shall not exceed 0.5% by mass.

(j) The use of public fill as fill material for earthworks shall only be permitted if the fill material complies with the particular requirements stated in the Contract and is reviewed without objection by the Project Manager.

(k) Well-graded material shall consist of material which has a coefficient of uniformity

exceeding 10.


(l) Uniform-graded material shall consist of material which has a coefficient of uniformity of 10 or less.

Table 7.1: Particle Size Distributions of Fill Material

Percentage by mass passing

Size BS test sieve Type of fill material

400 mm 200 mm 75 mm 20 mm 600 mm 63 mm

Fine fill material - - 100 - - -

General fill material - 100 75 - 100 - - -

Special fill material - - 100 - - 0 - 45

Granular fill material - - 100 - 0 - 5 -

Rock fill material (Grade 200) - 100 20 - 75 0 - 50 - -

Rock fill material (Grade 400) 100 20 - 75 10 - 30 0 - 25 - -

7.3 SUBMISSIONS 7.3.1 Particulars of Earthworks

(a) The following particulars of the proposed materials and methods of construction for earthworks shall be submitted to the Project Manager for review:

(i) details of Contractor's Equipment and haulage vehicles;

(ii) methods of excavation and of deposition and compaction of fill material;

(iii) use of different types of excavated material and sources of imported fill

material;

(iv) arrangements for stockpiling excavated material and fill material and for disposing of earthworks material;

(v) methods of controlling the moisture content of fill material;

(vi) methods of controlling surface water and groundwater and of protecting

earthworks and earthworks material from damage due to water and from weather conditions which may affect the earthworks or earthworks material;

(vii) types of instrumentation and methods of monitoring groundwater levels;

(viii) types of instrumentation and methods of monitoring the ground and structures

for movements;

(ix) methods of dealing with existing water courses so as to maintain existing drainage path; and

(x) any special methods/sequence of work for earthworks adjacent to structures.


(b) Where the Contractor proposes to form temporary slopes or proposes any form of temporary support to earthworks, then he shall submit full supporting calculations and the provisions of Section 2 of this General Materials and Workmanship Specification shall apply.

7.4 WORKMANSHIP 7.4.1 Ownership of Earthworks Material

(a) Earthworks material within the Site at the commencement of the Contract shall

remain the property of the Employer except as stated in Clause 7.4.1(b). (b) Earthworks material which is required to be disposed of by the Contractor shall

become the property of the Contractor when it is removed from the Site and shall be disposed of in accordance with the Employer’s guidelines for disposal of construction waste and Section 7 of the General Specification.

7.4.2 Temporary Works for Earthworks

The Contractor shall submit to the Project Manager for review the full supporting calculations for any proposed temporary slopes or any form of temporary support to earthworks and the provisions of Section 2 of this General Materials and Workmanship Specification shall apply.

7.4.3 Temporary Access and Drainage

The Contractor shall provide and maintain temporary access roads and temporary drainage and shall divert and reinstate permanent drainage systems. Temporary access roads shall be provided with drainage ditches over their full length. Details of any such temporary works shall be submitted to the Project Manager and his consent in writing shall be obtained before construction commences.

7.4.4 Handling and Storage of Earthworks Material

(a) Earthworks material shall not be handled or stored in a manner which will result in segregation, deterioration, erosion or instability of the material.

(b) Different types of earthworks material shall be kept separate from each other.

Earthworks material which is suitable for use as fill material shall be maintained in a suitable condition and shall not be contaminated.

7.4.5 Protection from Water and Weather and Protection of Existing Instruments

(a) Earthworks after site clearance, excavation or filling and earthworks material after excavation shall be kept free from water and shall be protected from damage due to water and from exposure to weather conditions which may affect the earthworks or earthworks material. The measures to be taken shall include the following:

(i) all safety measures stated in the Contract;

(ii) surfaces shall be maintained in a stable condition and shall be formed to falls to

shed water and to prevent ponding;

(iii) the area of exposed surfaces shall be kept to a minimum;


(iv) surface water flowing into the Site and within the Site shall be intercepted and diverted from the Site to a suitable discharge point;

(v) at each intersection and abrupt change of direction of surface drainage channels

an accessible catchpit shall be provided;

(vi) all drainage works shall be kept clear of debris and silt; and

(vii) where partially completed drainage works discharge within the Site a temporary conduit shall be provided to the discharge point.

(b) Excavations for structures, pits and trenches shall not be carried out on or adjacent to

slopes unless measures are taken to drain the excavation and to prevent water from the excavation entering the slope.

(c) Geotechnical Instrumentation

(i) The Contractor shall note the existence of any instrumentation, for example,

piezometers, inclinometers and surface movement monuments, and shall install a prominent marker post at each such instrument.

(ii) Instruments shall not be removed or disturbed in any way except in accordance

with sub-clauses (iii) and (iv) below. Any instrument damaged by the Contractor shall be reinstated by him immediately.

(iii) Certain instruments shall be maintained as the Works proceed around them.

Working methods shall take account of this requirement and piezometer / settlement marker / inclinometer tubes shall be shortened or lengthened as necessary. When the adjacent works have reached their final level, a protective concrete box or other surface structure shall be constructed and a prominent marker post shall be installed.

(iv) Certain instruments shall be removed as the Works proceed but not until the

Project Manager has confirmed that it is necessary for the progress of the Works in each case.

7.4.6 Earthworks Material Allowed to become Unsuitable or to Deteriorate

(a) Earthworks material which has been used, or is required for use, in the Permanent Works and which is allowed to become unsuitable such that in the opinion of the Project Manager it no longer complies with the specified requirements for that type of material shall be replaced or dealt with by methods reviewed without objection by the Project Manager.

(b) Earthworks material which is not stated in the Contract to be excavated and which the

Contractor causes or allows to deteriorate such that in the opinion of the Project Manager the Permanent Works will be affected shall be replaced or dealt with by methods reviewed without objection by the Project Manager.

(c) Material provided to replace earthworks material which has been allowed to become

unsuitable or which the Contractor causes or allows to deteriorate shall be an equivalent material reviewed without objection by the Project Manager. The replacement material shall have the same volume after compaction as the material replaced.

(d) The material which is to be replaced shall be disposed of by the Contractor.


7.4.7 Additional Excavation and Stabilisation

(a) Earthworks material which is not stated in the Contract to be excavated but which in the opinion of the Project Manager has inadequate strength, durability or stability shall be dealt with by additional excavation and filling as stated in Clause 7.4.7(b) or by stabilisation as stated in Clause 7.4.7(c).

(b) Additional excavation shall be carried out and the resulting voids shall be dealt with

as follows:

(i) general fill material, fine fill material or special fill material shall be deposited and compacted below areas of fill and below formations other than in rock;

(ii) Grade 15 concrete shall be placed and compacted below formations in rock;

and

(iii) granular fill material shall be deposited below standing water.

(c) Stabilisation shall be carried out using rock fill material (Grade 400) deposited directly into the original unstable material and compacted to form a stable foundation on which to construct the subsequent work.

(d) During the wet season where temporary bare earth slope faces are unavoidable they

shall be protected with impermeable sheeting well secured against the wind. Where slope faces steeper than 50º and higher than 5 m are to be temporarily exposed for more than two weeks temporary hard surfacing, such as chunam, shall be provided and temporary drains shall be installed.

7.4.8 Removal of Earthworks Material

Earthworks material which is required for use in the Permanent Works as fill material shall not be removed from the Site. The Contractor shall notify the Project Manager before any earthworks material is removed from the Site.

7.4.9 Disposal of Excavated Material

(a) Excavated material which cannot be selected, processed or mixed in a practical manner to make it suitable for use in the Permanent Works as fill material shall be disposed of by the Contractor unless otherwise stated in the Contract.

(b) The Contractor shall not dispose of any materials of any type obtained from within

the Site without the permission of the Project Manager. 7.4.10 Disposal of Surplus Fill and Fill Containing Materials as Defined in Clause 7.2.1(b)

(a) Pursuant to Clause 7.4.10(b), excavated or imported materials (other than those dredged), surplus to the requirements of or unsuitable for use in the Works as defined in Clause 7.2.1(b) shall be disposed of by the Contractor as defined below. The Contractor shall, prior to disposal, screen the surplus materials to yield general fill materials and rock fill material.

(b) Rock fill material which cannot be incorporated in the Works shall be deposited in the

stockpiles designated by the Project Manager.


(c) Fill materials other than rock fill material and materials as defined in Clause 7.2.1(b)(i) to (vi) which cannot be incorporated in the Works shall be deposited and compacted in accordance with Clause 7.4.26 in the stockpiles designated by the Project Manager.

(d) Materials as defined in Clause 7.2.1(b)(i) to (vi) shall become the property of the

Contractor who shall dispose of such materials off-Site. 7.4.11 Use of Excavated Material

(a) Excavated material required for use in the Permanent Works which is capable of being selected, processed and mixed to make it suitable for use as fill material shall not be used for any other purposes.

(b) Such excavated materials shall be selected and/or processed by using a suitable

screening system. If necessary, the Contractor shall blend materials to obtain fill materials to meet the various requirements.

(c) Excavated material which is required for use in the Permanent Works as fill material

and which the Project Manager permits to be removed from the Site or used for other purposes shall be replaced by an equivalent material reviewed without objection by the Project Manager. The replacement material shall have the same volume after compaction as the material which is replaced.

7.4.12 Boulders in Excavations

Boulders which project through the earthworks final surface or formation shall be dealt with as excavation proceeds by methods reviewed without objection by the Project Manager. Boulders shall not be left protruding.

7.4.13 Excavation

(a) Temporary supports or other methods shall be used to maintain excavations in a stable condition and to prevent settlement of structures or utilities due to excavation or dewatering.

(b) Contractor's Equipment or other vehicles shall not be operated or parked adjacent to

excavations. Earthworks material or other materials shall not be placed adjacent to excavations unless this has been allowed for in the design of the Temporary Works for the support of the excavation.

(c) Temporary groundwater control of excavation shall be carried out in accordance with

the requirements stated in Clause 8.18.9 and Clauses 8.19.16 to 8.19.19 inclusively. 7.4.14 Excavations Adjacent to Structures and Utilities

(a) Excavations shall be carried out by hand adjacent to, and around utilities that are known, proven or suspected to exist.

(b) Excavations adjacent to existing structures shall be carried out by hand.


7.4.15 Excavations for Structures, Pits and Trenches

(a) Excavations for structures, pits and trenches shall be the minimum size necessary to construct the Permanent Works.

(b) The length of trench excavation left open at any one time shall not exceed that

permitted by the Project Manager. (c) Trenches for utilities in areas of fill shall not be excavated until the fill material has

been deposited and compacted up to the earthworks final surface or formation or up to 1 m above the top of the utility, whichever is lower.

(d) The sides of pits and trenches shall be adequately supported at all times. Alternatively

except where the Contract expressly requires otherwise they may be suitably battered. (e) The bottom of all excavations shall be levelled carefully and stepped or benched

horizontally as shown on the Employer’s Drawings. Any pockets of soft material or loose rock in the bottoms of pits and trenches shall be removed and the resulting cavities and any large fissures filled with Grade 10 concrete. After the placing of any blinding concrete required by the Contract, no trimming of the side faces shall be carried out for 24 hours.

(f) The Contractor shall make good with fill material as defined in Clause 7.2.1 or concrete

as directed by the Project Manager:

(i) Any excavation greater than the net volume required for the works as described in the Contract.

(ii) Any additional excavation at or below the bottom of foundations to remove

material which the Contractor allows to become unsuitable. 7.4.16 Rock Splitting Using a Special Technique

(a) Where shown on the Employer’s Drawings or directed by the Project Manager, non-explosive rock-splitting techniques shall be used to form the finished rock face. Such techniques include expanding chemical grout and uncharged drillholes.

(b) Parallel holes shall be drilled in the final excavation face. The spacing of the holes

shall be determined in relation to the diameter of the drillhole and shall be within the range of 400-1000 mm.

(c) Before starting splitting along the final excavation face in any given type and

condition of rock, trials shall be carried out at least 6 m away from the final face to produce results acceptable to the Project Manager, with a minimum trial length of 4 m. The following details of the procedures used shall be submitted to the Project Manager at least 24 hours before starting to drill in the final excavation face:-

(i) diameter, spacing, depth and subdrill of rock-splitting holes; and

(ii) when using expanding chemical grout, chemical composition of the grout and

mix ratio of chemical (kg): water (kg).

(d) After review without objection by the Project Manager of the trial results, the procedures used shall be the same in all respects as in the trial. Drilling a set of rock-splitting holes in the plane of the final rock-face shall not proceed until at least 50% of the face formed by the previous adjacent splitting has been exposed and the results assessed.


(e) If the rock-splitting results deteriorate because of changes in the jointing or degree of weathering of the rock mass, without a major change necessitating new trials as sub-clause (c) hereof, procedures shall be modified as necessary, with the agreement of the Project Manager, and rock splitting shall continue in lengths of not more than 6 m until fully satisfactory results are again achieved. If necessary in the opinion of the Project Manager, new proposals shall be submitted in accordance with Clause 7.4.16(c) and this Clause, before continuing.

(g) (f) Chemical grout holes shall not be charged until the rock broken by previous

operations has been mucked out. (g) When the chemical grout has expanded fully, the rock in front of the plane of the

drillholes shall be broken out and all traces of the solidified chemical removed. (h) After drilling the rock-splitting holes, (for uncharged drillholes) the rock in front of

the plane of the drillholes shall be broken out by a mechanical rock breaker. 7.4.17 Surface Preparation for Fill Material

Except as stated in Clause 7.4.34, surfaces on which fill material is to be deposited shall be prepared after site clearance in accordance with the following requirements:

(a) topsoil, grass, and other organic matter shall be removed; (b) soft spots, boulders and other materials which are unsuitable or unstable shall be

removed; (c) watercourses shall be diverted in accordance with methods reviewed without

objection by the Project Manager; (d) benches shall be cut and sub-soil drainage systems installed as stated in the Contract; (e) voids shall be dealt with as stated in the Contract or instructed by the Project

Manager; and (f) topsoil, soil, material other than rock and all material which is capable of being

scarified, shall be scarified to a depth of 200 mm and compacted to the same standard as the fill material which is to be deposited.

7.4.18 Commencement of Deposition of Fill Material

The Contractor shall notify the Project Manager before deposition of fill material starts in any area of fill.

7.4.19 Haulage of Fill Material

Haulage of fill material to an area of fill shall commence only when the specified requirements for relative compaction of the fill material have been achieved.


7.4.20 Deposition of Fill Material

(a) Fill material obtained from excavations within the Site shall be deposited in its final location as soon as practicable after it has been excavated.

(b) Fill material shall be deposited in layers of a thickness appropriate to the compaction

method to be used. (c) Layers of fill material shall be horizontal, except for any gradient required for

drainage, and the thickness of each layer shall be uniform over the area to be filled. (d) Except in excavations for structures, pits and trenches, if the difference in level

between adjacent areas to be filled exceeds 1 m the edge of the higher area shall be benched before fill material is placed against it.

(e) The construction of the Works shall be controlled in such a manner that any

compaction of the fill material, including that resulting from the passage of Contractor's Equipment or haulage vehicles is uniform.

(f) Except as stated in Clause 7.4.34, fill material shall not be deposited by end-tipping,

by pushing loose material down slope faces or by other methods which may result in segregation or inadequate compaction of the fill material.

(g) Isolated boulders each within the range 0.015 cu m to 0.10 cu m in size may be

incorporated in embankments not of rockfill at the discretion of the Project Manager provided that the specified compaction requirements are met and no stone exceeding 0.015 cu m shall be placed less than 2 m below formation level of carriageways or hardshoulders.

(h) In reclamation, before any other material is dumped within 90 m of any seawall,

material shall first be dumped immediately behind the wall to a width of 15 m to 30 m by working outwards from the wall unless the Project Manager directs otherwise. If directed, the Contractor shall also dump material in bunds to form self-contained areas before filling the remaining area.

(i) An accurate and up-to-date record showing dates, weather conditions, approximate

elevations, source of materials, compactive effort etc shall be kept by the Contractor showing when fill is placed in various locations within the Site. This record shall be available for inspection by the Project Manager. The Contractor shall also record the results of all compaction and in-situ density tests and shall identify these results with the various locations and elevations at which fill material has been placed and the location from which the fill material was obtained.

7.4.21 Overfilling

In areas of fill formed of fill material other than rock fill material, earthworks final surfaces sloping at a gradient exceeding 1 vertical to 3 horizontal shall be formed by overfilling and cutting back after compaction. Over-filling shall extend beyond the earthworks final surface by a horizontal distance of 0.5 m or two times the thickness of the compacted layer, whichever is greater.


7.4.22 Deposition of Fill Material Adjacent to Structures and Utilities

(a) Except as stated in Clause 7.4.22(d), fill material deposited within 0.5 m of a structure or utility shall be fine fill material unless otherwise stated in the Contract. In addition, the material may contain up to 5% by weight of fresh, slightly decomposed or moderately decomposed rock fragments of up to 200 mm provided that these do not cause any damage to structures, nor do they interfere with the compaction requirements.

(b) Fill material shall not be deposited adjacent to or above structures or utilities until the

construction of the structure or utility is sufficiently advanced to accept the imposed forces without disturbance or damage.

(c) Fill material shall be deposited evenly on all sides of structures and utilities and in

such a manner that the structure or utility is not disturbed or damaged. (d) Unless otherwise stated in the Contract, fill material around water, sewage and

drainage pipes which are constructed as part of the Permanent Works shall be special fill material as defined in Clause 7.2. Fill material shall be deposited in layers not exceeding 100 mm thick to a level of 300 mm above the top of the pipe. Fill material shall be deposited in such a manner that the layer on one side of the pipe is not more than 100 mm higher than the layer on the other side.

(e) Backfill material more than 300 mm above the top of the pipe should be general fill

material compacted in layers not exceeding 250 mm thick. (f) Fill material shall be brought up to original ground level or the earthworks final level or

as directed by the Project Manager. 7.4.23 Deposition of Rock Fill Material

(a) The final compacted thickness of each layer of rock fill material shall exceed 1.5 times and shall not exceed twice the nominal grade size of the rock fill material.

(b) The surface voids of each layer of rock fill material shall be filled with fragments of

rock before the next layer is deposited. The final surface of rock fill material shall also be blinded with fine fill material.

7.4.24 Deposition of Fill Material in Excavations for Structures, Pits and Trenches

If sheet piling, timbering or other temporary supports to excavations for structures, pits and trenches are not to be left in place, the sheet piling, timbering or supports shall be removed as deposition of fill material proceeds. The supports shall be removed in such a manner that the stability of the adjacent ground is maintained and the compacted fill material is not disturbed.

7.4.25 Deposition Compaction of Materials in Trenches and Pits in Carriageways and

Footways

(a) Trenches and pits cut in carriageways and footways, which are to remain open to traffic only during the term of the Contract, shall be backfilled and compacted, to the underside of the adjacent pavement construction or to a level 260 mm below the surface, whichever is the lower. The next layer of backfilling shall be sub-base to a level 60-100 mm, as directed by the Project Manager, below the surface of adjacent construction.


(b) A tack coat of bituminous emulsion shall be applied to the surface of the compacted sub-base and the edges of the existing pavement except the edges of the friction course exposed by the excavation. Tack coating shall be applied as specified in Clause 9.5.6(d).

(c) The backfilling shall be completed with 60-120 mm of bituminous roadbase, as

specified in Clause 9.3.2. 7.4.26 Compaction of Fill Material

(a) Fill material in areas of fill shall be compacted in layers to a stable condition as soon as practicable after deposition and in a manner appropriate to the location and to the material to be compacted.

(b) The Contractor shall notify the Project Manager before the next layer is deposited on

each layer of compacted fill material. (c) Except as stated in Clauses 7.4.29(b), 7.4.27(a), 7.4.32(b) and 7.4.35, fill material

shall be compacted to obtain a relative compaction of at least 95% throughout unless otherwise stated in the Contract.

7.4.27 Compaction of General Fill Material with a Large Portion of Coarse Material

(a) General fill material with material of which less than 90% passes a 20 mm BS test sieve, where it is not possible to determine the moisture content and maximum dry density according to the testing methods stated in Appendices A7.1 to A7.5, shall be compacted to the requirements of Sub-Clauses (b), and (c), or (d) of this clause.

(b) Spread and level each horizontal layer of general fill material with a thickness not less

than 1.5 times of the maximum size of the general fill material and not exceeding the maximum depth of compacted layer in accordance with Table 7.2. If this criterion is not met due to the presence of over-sized coarse material in the general fill, the over-sized coarse material shall be removed or broken down to sizes acceptable to the Project Manager. Each layer shall be systematically compacted by a vibratory roller with the stipulated minimum number of passes corresponding to the minimum static load per 100 mm width of the roller.

(c) The number of passes of the roller shall only be counted when the roller has travelled

on the material to be compacted at a speed of not more than 2 km per hour with full vibration. Plant other than a vibratory roller used to carry out material spreading or to provide some preliminary compaction only to assist the use of heavier plant shall be disregarded in counting the number of passes.

(d) Variation from the method or the use of plant different from that specified in Sub-

Clause (b) of this Clause will be permitted only if the Contractor demonstrates by Site trials that equivalent compaction is achieved by the alternative method. The procedure to be adopted for these Site trials shall be agreed with and reviewed without objection by the Project Manager.

(e) Without prejudice to the General Conditions and in order that the Project Manager

may make proper provision for the supervision of compaction in the permanent work, the Contractor shall, not less than 48 hours before he proposes to carry out compaction processes, apply in writing to the Project Manager for permission to do so.


(f) When materials of widely divergent characteristics are used in embankments and fill areas they shall be spread and compacted in separate clearly defined areas.

(g) If more than one class of material is being used in such a way that it is not practicable

to define the areas in which each class occurs, compaction plant shall be operated as if only the material which requires the greatest compactive effort is being compacted.

Table 7.2: Compaction Requirement for General Fill Material with a Large Portion of

Coarse Material

Force per 100mm width Well-graded material Uniform-graded material

(kN)

Maximum depth of

compacted layer (mm)

Minimum no. of passes

Maximum depth of

compacted layer (mm)

Minimum no. of passes

0.25-0.45 150 16 0.46-0.70 150 12 0.71-1.25 125 12 150 6 1.26-1.75 150 8 200 10 1.76-2.30 150 4 225 12 2.31-2.80 175 4 250 10 2.81-3.50 200 4 275 8 3.51-4.20 225 4 300 8 4.21-4.90 250 4 300 8

7.4.28 Moisture Content of Fill Material

Fill material other than rock fill material and material as stated in Clause 7.4.27(a) shall be at optimum moisture content during compaction. Fill material at a moisture content within ± 3% of the optimum moisture content, may be acceptable provided that it is capable of compaction, in accordance with the specified requirements, to form stable areas of fill.

7.4.29 Compaction of Fill Material Adjacent to Structures and Utilities

(a) Fill material shall be compacted in such a manner that structures or utilities are not disturbed or damaged.

(b) Fill material around water, sewage and drainage pipes which are constructed as part

of the Permanent Works shall be compacted by hand-rammers or manually operated power equipment. Fill material within 300 mm above the top of sewage and drainage pipes shall be compacted to obtain a relative compaction of at least 85% throughout.

7.4.30 Compaction of Rock Fill Material

(a) Every layer of rock fill material shall be compacted by at least eight passes of a vibrating roller or by other equivalent compaction method reviewed without objection by the Project Manager. The final surface of rock fill material shall be compacted by at least two additional passes of a vibrating roller or by other equivalent compaction method reviewed without objection by the Project Manager.

(b) Vibratory rollers used for the compaction of rock fill material shall have a static load

per 100 mm width of roll of at least 2 kN for layers with a compacted thickness not exceeding 500 mm and at least 4 kN for layers with a compacted thickness exceeding 500 mm.


7.4.31 Completion of Earthworks Final Surfaces

(a) Earthworks final surfaces shall be completed to a stable condition as soon as practicable after excavation or after deposition and compaction of fill material has been completed. The subsequent Permanent Works or surface protection shall be carried out as soon as practicable after the earthworks final surface has been completed.

(b) Earthworks final surfaces shall be completed to smooth alignments without abrupt

irregularities unless otherwise stated in the Contract. 7.4.32 Completion of Formations

(a) Formations above structures or utilities shall be completed after construction of the structure or utility.

(b) Except in excavations in rock and in areas of fill formed of rock fill material or fill

material as stated in Clause 7.4.27(a), formations shall be compacted to obtain a relative compaction of at least 98% to a depth of 200 mm below the formation.

(c) Proof rolling shall be carried out on formations unless otherwise reviewed without

objection by the Project Manager. The Project Manager shall be notified prior to commencement of proof rolling. The formation shall be rolled by at least two passes of a non-vibrating rubber tyred roller. The roller shall have a static load per 100 mm width of roll of at least 4 kN and shall travel at a speed not exceeding 2 km/h. Any defect in the formation which is revealed during proof rolling by deformation of the formation which in the opinion of the Project Manager is excessive shall be made good as directed by the Project Manager.

(d) After all other formation work and testing have been completed and damage caused

by testing reinstated, formations for pavements shall be rolled with one pass of a smooth steel-wheeled non-vibrating roller. The roller shall have a load per 100 mm width of roll of at least 2 kN.

(e) Formations which will not be immediately covered shall be protected by methods

reviewed without objection by the Project Manager. (f) Surface irregularities in formation after trimming of the rock excavation shall be

regulated to the requirements of this Section with granular fill material, no-fines concrete or lean concrete as determined by the Project Manager.

7.4.33 Protection of Earthworks Final Surfaces and Formations

(a) Earthworks final surfaces and formations shall be maintained in a stable condition and shall be protected from damage due to water or other causes and from exposure to conditions which may adversely affect the surface.

(b) Formations shall not be used by Contractor's Equipment or vehicles other than those

which are essential to construct the subsequent work. (c) If the Contractor wishes to continue to use the surface of embankments for construction

traffic before trimming to formation level he shall bring up and maintain the area between the extremities of the carriageway(s), including (if any) central reserve and hardshoulders to a level not less than 150 mm above formation level whereupon construction traffic will be allowed to use the surface so formed but any damage to the earthworks final surface caused by the use of such surface shall be made good by the Contractor.


(d) In areas of shallow filling where after removal of topsoil the ground level is within 300 mm of the earthworks final surface level, construction traffic shall not use the surface unless the Contractor brings up and maintains the surface level at least 300 mm above the earthworks final surface level. Any damage to the subgrade arising from such use shall be made good by the Contractor with material having the same characteristics as the damaged material.

7.4.34 Deposition of Fill Material in Intermediate Areas of Fill

Fill material may be deposited in intermediate areas of fill by end-tipping or by pushing into position until it is sufficient to form a stable foundation on which to construct the subsequent work.

7.4.35 Compaction of Fill Material in Intermediate Areas of Fill

Fill material in intermediate areas of fill up to the level stated in Clause 7.4.34 shall be compacted to a degree which is practicable. Except as stated in Clause 7.4.27(a), fill material above the level stated in Clause 7.4.34 shall be compacted to obtain a relative compaction as determined by the modified Proctor test as defined in BS 1377-4;1990 of at least: (a) 90% throughout; (b) 95% within 1.5 m of earthworks final surfaces and formations; and (c) 98% within 200 mm of formations.

7.4.36 Tolerances: Earthworks Final Surfaces and Formations

(a) Earthworks final surfaces and formations shall be within the tolerances stated in Table 7.3 of the specified lines and levels. The tolerances for formations do not apply for pipes or preformed structures which require support over their complete length or area.

(b) In excavation, a positive tolerance refers to insufficient excavation and a negative

tolerance refers to excess excavation. In areas of fill, a positive tolerance refers to excess fill material and a negative tolerance refers to insufficient fill material.


Table 7.3: Tolerances for Earthworks Final Surfaces and Formations

Tolerance (mm) Type of surface Method of forming surface + -

Excavation except in rock 0 25 Excavation in rock 0 150 Formations for structures and

utilities Deposition and compaction of fill material

0 25

Excavation except in rock 0 50 Excavation in rock 0 150

Formations for pavements including carriageways,

footways, cycletracks, paved areas, aircraft pavements and

railway trackbeds.

Deposition and compaction of fill material

0 50


Earthworks final surfaces other than formations, with a gradient not exceeding 1 vertical to 10

horizontal Deposition and compaction of

fill material 0 100


Other earthworks final surfaces Deposition and compaction of

fill material 100 100

7.4.37 General Ground Treatment: Vibrocompaction

Where treatment of the ground is to be carried out using methods of vibro-compaction and/or vibro-replacement, the Contractor shall submit to the Project Manager for his review details of the method, Contractor's Equipment and materials he intends to use and, notwithstanding any other requirements of the Contract, the testing he intends to carry out to demonstrate that he has achieved the degree of ground improvement as specified. The Contractor shall demonstrate to the Project Manager's satisfaction that the persons carrying out the work are suitably experienced.

7.4.38 Existing Instrumentation

(a) The Contractor shall note the existence of any instrumentation (e.g. piezometers, inclinometers and surface movement monuments) shown on the Employer’s Drawings and shall install a prominent marker post at each such instrument.

(b) Instruments shall not be removed or disturbed in any way except in accordance with

Sub-Clauses (c) and (d) below. Any instrument damaged by the Contractor shall be reinstated by him immediately and at his own expense.

(c) Certain instruments, if so shown on the Employer’s Drawings, shall be maintained as

the Works proceed around them. Working methods shall take account of this requirement and piezometer/settlement marker/inclinometer tubes shall be shortened or lengthened as necessary. When the adjacent works have reached their final level, a protective concrete box (or other surface structure as shown on the Employer’s Drawings) shall be constructed and a prominent marker post shall be installed.

(d) Certain instruments, if so shown on the Employer’s Drawings, shall be removed as

the Works proceed but not until the Project Manager has confirmed that it is necessary for the progress of the Works in each case.


7.4.39 Excavation for Utilities Trenches in Hard Materials

The Contractor shall form trenches for the installation of utilities at locations where excavation is in hard materials. He shall programme the trench excavation so that it is completed in advance of the work by the utility undertaking. He shall backfill the trenches with fine fill material in horizontal layers and compact as directed by the Project Manager.

7.5 INSPECTION, TESTING AND COMMISSIONING 7.5.1 Batch: Fill Material

A batch of fill material is any quantity of fill material of the same type and which has similar properties throughout. For the purpose of testing for moisture content and relative compaction a batch shall, in addition to the above, be fill material which is deposited in a single layer in any area of fill presented by the Contractor for testing on one occasion.

7.5.2 Samples: Fill Material

(a) Each sample of fill material shall consist of at least four increments taken from different parts of the batch. The increments shall be combined and thoroughly mixed and shall then be divided by quartering or by using a riffle box to obtain specimens of an appropriate size to carry out the individual tests.

(b) The size of samples of fill material other than rock fill material shall be in accordance

with BS 1377, Part 1, Section 7. Each sample of rock fill material of grade size not exceeding 200 shall have a mass of at least 250 kg and each sample of rock fill material of grade size exceeding 200 shall have a mass of at least 1000 kg.

7.5.3 Test – Fill Material General

All tests as required by the Project Manager shall be carried out by a HOKLAS accredited laboratory reviewed without objection by the Project Manager.

7.5.4 Samples: Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient of

Uniformity, Sulphate Content

Samples of fill material to be tested for particle size distribution, liquid limit, plasticity index, coefficient of uniformity and sulphate content shall be delivered at least 14 days, before deposition of the fill material starts. The number of samples to be provided from each batch shall be as stated in Table 7.4.

Table 7.4: Number of Samples to be Tested for Particle Size Distribution, Liquid

Limit, Plasticity Index, Coefficient of Uniformity, Sulphate Content, Optimum Moisture Content and Maximum Dry Density

Description Size of batch No. of samples per batch

0 - 3,000 m³ 3 Special fill material

exceeding 3,000 m³ 1 for each 1,000 m³ or part thereof

0 - 15,000 m³ 3 Fill material other than special fill material exceeding 15,000 m³ 1 for each 5,000 m³ or part thereof


7.5.5 Testing: Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient of Uniformity, Sulphate Content

(a) Each sample of fill material taken as stated in Clause 7.5.4 shall be tested to

determine the particle size distribution. In the case of special fill material testing shall include calculation of the coefficient of uniformity as stated in Clause 7.5.5(d). Each sample of fill material other than rock fill material shall be tested to determine the liquid limit and the plasticity index of that portion of the fill material passing a 425m BS test sieve. Each sample of fill material which will be deposited within 500 mm of concrete, cement bound material, cementitious material or metalwork shall be tested to determine the soluble sulphate content.

(b) The method of testing shall be in accordance with the following tests as stipulated in

GEO Report No. 36 - Methods of Test for Soils in Hong Kong for Civil Engineering Purposes (Phase 1 Tests):

Particle size distribution : Clause 7.5.5(c) Liquid limit : test 2.4.3 Plasticity index : test 2.5.3 Soluble sulphate : test 3.5.5 Total sulphate : test 3.5.5

(c) The particle size distribution of fill material passing a 75mm BS test sieve shall be determined in accordance with GEO Report No. 36, Test 2.9.2A or 2.9.2B, whichever as instructed by the Project Manager. The size of particles of fill material which do not pass a 75 mm BS test sieve shall be taken as the largest dimension measured in any plane.

(d) The coefficient of uniformity (Cu) shall be calculated from the equation:

Cu = D60/D10

Where:

- D60 and D10 are the equivalent sieve sizes in millimetres, interpolated from

the particle size distribution curve, through which 60% and 10% of the fill material would pass respectively.

7.5.6 Non-compliance: Particle Size Distribution, Liquid Limit, Plasticity Index, Coefficient

of Uniformity, Sulphate Content

(a) If the result of any test for soluble sulphate content of fill material does not comply with the specified requirements for soluble sulphate content, each sample shall be tested to determine the total sulphate content.

(b) If the result of any test for particle size distribution, liquid limit, plasticity index,

coefficient of uniformity or total sulphate content of fill material does not comply with the specified requirements for the property, additional samples shall be provided from the same batch and additional tests for the property shall be carried out. The number of additional samples shall be as stated in Table 7.4.


7.5.7 Samples: Optimum Moisture Content, Maximum Dry Density

(a) Samples of fill material to be tested for optimum moisture content and maximum dry density shall be delivered at least 72 hours before deposition of the fill material starts. The number of samples to be provided from each batch shall be stated in Table 7.4

(b) The Contractor shall notify the Project Manager of the exact location in which the fill

material from which each sample is taken is to be deposited. (c) Samples to be tested for optimum moisture content and maximum dry density shall

also be taken after the fill material has been deposited in its final position, at intervals of not more than 28 days.

(d) Samples shall not be provided from:

(i) Fill material including rock fill material which contains an insufficient proportion of particles passing a 20 mm BS test sieve to permit determination of the moisture content and maximum dry density; and

(ii) fill material which is to be deposited as stated in Clause 7.4.34.

7.5.8 Testing: Optimum Moisture Content, Maximum Dry Density

(a) Each sample of fill material taken as stated in Clause 7.5.7 shall be tested to determine the optimum moisture content and the maximum dry density.

(b) The method of testing shall be in accordance with the following:

Optimum moisture content : BS 1377 test 12 Maximum dry density : BS 1377 test 12 adjusted in accordance with

Appendix A7.5 where appropriate. (c) If permitted by the Project Manager, the Hilf method stated in Appendix A7.4 may be

used instead of the methods stipulated in Clause 7.5.8(b) to determine the optimum moisture content and maximum dry density.

(d) If in the opinion of the Project Manager there is any undue discrepancy between the

results of tests for optimum moisture content of fill material using methods stipulated in Clause 7.5.8(b) and the results of tests using the Hilf method, the results of tests using methods stipulated in Clause 7.5.8(b) shall prevail.

7.5.9 Consistency: Optimum Moisture Content, Maximum Dry Density

If the result of any test for optimum moisture content or maximum dry density of fill material indicates that the batch contains material which differs to such an extent that subsequent tests for relative compaction may be affected, the batch shall be divided into smaller batches; each of the smaller batches shall comprise material with similar properties throughout. Additional samples shall be provided from each of the smaller batches and additional tests for optimum moisture content and maximum dry density shall be carried out. The number of additional samples shall be as stated in Table 7.4.


7.5.10 Samples: Moisture Content

(a) Samples of fill material to be tested for moisture content shall be taken during deposition and compaction of fill material and shall be delivered to the laboratory not more than 1 hour after the fill material has been deposited in its final position.

(b) The number of samples to be provided from each batch shall be as stated in Table 7.5.

Samples shall not be provided if, in accordance with Clause 7.5.7 d(i) or (ii), the optimum moisture content has not been determined.

7.5.11 Testing: Moisture Content

(a) Each sample of fill material taken as stated in Clause 7.5.10 shall be tested to

determine the moisture content. (b) The method of testing shall be in accordance with one of the following methods:

(i) Method 1: GEO Report No. 36, Test 2.3.2A or Test 2.3.2B, whichever as

instructed by the Project Manager; or

(ii) Method 2: Microwave oven drying method as stated in Appendix A7.2.

Method 1 shall be used unless otherwise permitted by the Project Manager. 7.5.12 Compliance Criteria: Moisture Content

If in the opinion of the Project Manager there is any undue discrepancy between the results of tests for moisture content of fill material using Method 1 and the results of tests using Method 2 in Clause 7.5.11, the results of tests using Method 1 shall prevail.

7.5.13 Non-compliance: Moisture Content

If the result of any test for moisture content of fill material differs from the optimum moisture content by more than the specified amount, the moisture content of the whole of the batch of fill material shall be adjusted. Additional samples shall be provided from the same batch and additional tests for moisture content shall be carried out. The number of additional samples shall be as stated in Table 7.5.

Table 7.5: Number of Samples to be Tested for Moisture Content and Number of

Tests for Relative Compaction

Description Size of area of fill in

batch No. of samples/No. of tests per

batch

0 - 100 m² 3

100 - 500 m² 2 for each 100 m² or part thereof

Areas of fill in excavations for Structures, pits and trenches and on Formations

exceeding 500 m² 1 for each 100 m² or part thereof

0 - 1 ha 4 for each 1000 m² or part thereof 2 - 10 ha 3 for each 1000 m² or part thereof

Other areas of fill exceeding 10 ha 2 for each 1000 m² or part thereof


7.5.14 Testing: Relative Compaction

(a) Each batch of fill material shall be tested to determine the relative compaction. Tests shall be carried out after the fill material has been deposited and compacted in its final position. The number of tests on each batch shall be as stated in Table 7.5. Tests shall not be carried out on:

(i) fill material including rock fill material which contains an insufficient

proportion of particles passing a 20 mm BS test sieve to permit determination of the relative compaction; and

(ii) fill material which has been deposited as stated in Clause 7.4.34.

(b) Tests shall be carried out at positions which in the opinion of the Project Manager are

representative of the batch of compacted fill material as a whole. (c) Testing shall be carried out by the Contractor. (d) The relative compaction of fill material shall be determined in accordance with one of

the following methods:

(i) Method 1: The relative compaction (RC) shall be calculated from the equation:

RC = IDD/MDD x 100%

where:

- IDD is the in-situ dry density, determined as stated in Clause 7.5.14(e) - MDD is the maximum dry density, determined as stated in Clause 7.5.8(b)

Method 2: The relative compaction (RC) shall be calculated from the equation:

RC = IBD/MCBD x 100% where:

- IBD is the in-situ bulk density determined as stated in Clause 7.5.14(e) - MCBD is the maximum converted bulk density determined by the Hilf

method as stated in Appendix A7.4

Method 1 shall be used unless otherwise permitted by the Project Manager.

(e) The in-situ bulk density and the in-situ dry density of fill material shall be determined in accordance with one of the following methods:

(i) Method 1: GEO Report No. 36, Test 9.2.1or 9.2.2 as appropriate to the

grain size of the fill material; or (ii) Method 2: Nuclear densometer method as stated in Appendix A7.3.

Method 1 shall be used unless otherwise permitted by the Project Manager.


(f) The maximum converted bulk density of fill material of which more than 5% is retained on a BS 20 mm test sieve shall be adjusted as stated in Appendix A7.5.

7.5.15 Compliance Criteria: Relative Compaction

If in the opinion of the Project Manager there is any undue discrepancy between the results of tests for relative compaction of fill material using Method 1 and the results of tests using Method 2 in Clause 7.5.14, the results of tests using Method 1 shall prevail.

7.5.16 Non-compliance: Relative Compaction

If the result of any test for relative compaction of fill material does not comply with the specified requirements for relative compaction, additional tests for relative compaction shall be carried out on the same batch. The number of additional tests shall be as stated in Table 7.5.


APPENDIX A7.1

TEST METHODS FOR FILL MATERIAL A7.1.1 General

The definitions, terms, abbreviations, symbols, and grouping of materials stated in BS 1377: 1975 shall apply except as stated in Clauses A7.1.2 and A7.1.3.

A7.1.2 Terms and Symbols

Terms used in the Specification, and in BS 1377: 1975 are identified by the abbreviations and symbols stated in Table A7.1.1.

Table A7.1.1: Abbreviations and Symbols

Abbreviation/Symbol Term

BD bulk density

CBD Converted bulk density

DD dry density

IBD In-situ bulk density

IDD in-situ dry density

MDD Maximum dry density

MCBD Maximum converted bulk density

RC Relative compaction

w moisture content

wi in-situ moisture content

wo Optimum moisture content

A7.1.3 Grouping of Material

(1) Fine grained material is material of which at least 90% passes a 2 mm BS test sieve. (2) Medium grained material is material of which at least 90% passes a 20 mm BS test

sieve and more than 10% is retained on a 2 mm BS test sieve.


APPENDIX A7.2

DETERMINATION OF THE MOISTURE CONTENT OF FINE GRAINED AND MEDIUM GRAINED MATERIAL

BY THE MICROWAVE OVEN DRYING METHOD A7.2.1 Scope This method covers the determination of the moisture content of fine grained and medium

grained material as a percentage of the mass of the dry material. A7.2.2 Apparatus The following apparatus is required:

(1) A microwave oven with a timer and an adjustable power setting.

(2) An airtight container of microwave safe and non-reflective material.

(3) A balance readable and accurate to 0.01 g.

(4) A desiccator containing anhydrous silica gel. A7.2.3 Procedure

(1) The container shall be cleaned, dried and weighed to the nearest 0.01 g (m1).

(2) A specimen shall be crumbled and placed loosely in the container and the lid shall be replaced. Each specimen of fine grained material shall be at least 30 g and each specimen of medium grained material shall be at least 300 g. Specimens of medium grained material may be tested in several parts each less than 300 g and the results aggregated.

(3) The container and contents shall be weighed to the nearest 0.01 g (m2).

(4) The lid of the specimen container shall be removed and the container with its lid and

contents shall be placed in the microwave oven and dried. The specimen shall be considered to be dry when, after an initial drying period, successive weighings at intervals of 1 minute produce results which are the same to the nearest 0.01 g. Alternatively, the oven may be set to an appropriate time and power setting to dry the specimen as determined by calibration of the oven on soil of a similar type.

(5) After drying, the container and contents shall be removed from the microwave oven

and placed in the desiccator to cool.

(6) The lid shall be replaced and the container and contents shall be weighed to the nearest 0.01 g (m3).


A7.2.4 Calculation

The moisture content of the material (w) shall be calculated as a percentage of the dry mass of the material from the equation:

w = (m2 - m3)/(m3 - m1) x 100% where: - m1 is the mass of the container (g) - m2 is the mass of the container and contents before drying (g) - m3 is the mass of the container and contents after drying (g)


The following shall be reported:

(1) source and identification of the soil;

(2) the moisture content of the material to the nearest 0.1%; and

(3) that the test method used was in accordance with this General Materials and



APPENDIX A7.3

DETERMINATION OF THE IN-SITU BULK DENSITY AND THE IN-SITU DRY DENSITY OF FINE GRAINED

AND MEDIUM GRAINED MATERIAL BY THE NUCLEAR DENSOMETER METHOD

A7.3.1 Scope

This method covers the determination of the in-situ bulk density of fine grained and medium

grained material by the attenuation of gamma rays and calculation of the in-situ dry density using a moisture content determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

A7.3.2 Apparatus

The following apparatus is required:

(1) A nuclear device for the measurement of density (densometer). The details of construction of the densometer may vary but the following general requirements shall apply:

- The probe shall be an adjustable probe containing a gamma source which can be

readily positioned in a preformed hole. The probe assembly shall be graduated in increments not exceeding 50 mm and shall be constructed in such a manner that it will be securely held in the test depth position.

- The instrumentation shall display the results directly in metric units.

(2) A reference standard of uniform and constant density to establish the background

count and count reproducibility.

(3) Site preparation equipment, such as spades, straight-edges, scoops and brushes, required to prepare a suitably cleared and level surface to accommodate the densometer.

(4) A hole forming device, such as an auger or steel pin, to form a hole to accommodate

the probe. The device shall have a nominal diameter which exceeds the probe diameter by not more than 3 mm and shall be graduated to indicate the depth of the hole. The device shall have a guide which will ensure that the hole is formed normal to the prepared surface.

(5) Sampling equipment, such as augers, spades, picks, small digging tools, scoops,

airtight containers and bags, to obtain samples of the material.

(6) Apparatus for the determination of the moisture content in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.


A7.3.3 Procedure: Comparability of Test Methods

(1) Before using the densometer on material for which it has not previously been used, the results of determinations of in-situ bulk density using the densometer shall be compared with the results of determinations of in-situ bulk density in accordance with GEO Report No. 36, Test 9.2.2. The location of each determination in accordance with GEO Report No. 36, Test 9.2.2 shall correspond to the midpoint of the densometer probe and the gamma sensor. A minimum of ten pairs of determinations shall be carried out.

(2) If the difference between any pair of results does not exceed 0.08 Mg/m³ and if the densometer produces results which are both higher and lower than those produced in accordance with GEO Report No. 36, Test 9.2.2, the densometer may be used without correction.

(3) If either of the criteria stated in Clause A7.3.3(2) is not met, the densometer shall not

be used.

A7.3.4 Procedure: Routine Denosometer Check

The procedure for carrying out a routine densometer check shall be as follows: (1) The densometer shall be warmed up in accordance with the manufacturer's

recommendations.

(2) A standard count shall be carried out in accordance with the manufacturer's recommendations. The standard count shall be carried out by placing the reference standard on a hard, level surface consisting of material with a density of at least 1.6

Mg/m³. The reference standard shall be placed at a distance of at least 10 m from any other nuclear device and at least 3 m from any large object. At least three count readings shall be taken and the mean of the three readings shall be determined. The mean shall be the standard count reading for the day.

(3) The standard count reading for the day shall be compared with the mean of the

standard count readings for the previous 4 days. If the difference is greater than that recommended by the manufacturer or if no recommendation is made and the difference is greater than 1%, the densometer shall not be used.

(4) The densometer shall be left switched on with the probe in the locked position. If the

densometer is switched off a further standard count shall be carried out in accordance with Clause A7.3.4(2) and (3).

A7.3.5 Procedure: Determination of In-Situ Bulk Density

The procedure for determination of the in-situ bulk density shall be as follows:

(1) A level surface of sufficient size to accommodate the densometer shall be prepared

and cleared of all disturbed and loose material. The depth of any depression below the densometer shall not exceed 3 mm. Depressions exceeding 3 mm in depth shall be filled using fine sand or material taken from the adjacent soil which passes a 600 m BS test sieve.

(2) A suitable hole for the probe shall be prepared using the hole forming device. The

hole shall be normal to the prepared test area and at least 50 mm deeper than the intended test depth. If a driven pin is used to form the hole, the pin shall be rotated every two or three blows to facilitate its removal.


(3) The test depth shall be the same as the maximum depth required for determination of the in-situ bulk density in accordance with GEO Report No. 36, Test 9.2.1 or 9.2.2 as appropriate to the grain size of the material.

(4) The probe shall be positioned and inserted into the hole in such a manner that the

gamma source is shielded at all times. The probe shall be seated firmly against the side of the hole nearest to the back of the densometer by gently pulling the densometer backwards until contact is achieved. The operator shall ensure that the densometer is correctly seated and the depth setting on the control panel is the same as the probe depth.

(5) The operator shall ensure that there are no other radioactive sources within 10 m of

the densometer.

(6) Three readings of the in-situ bulk density shall be taken in accordance with the manufacturer's recommendations and the mean determined. If any one reading differs

from any other reading by more than 0.015 Mg/m³, additional readings shall be taken

until three consecutive readings which do not differ by more than 0.015 Mg/m³ are obtained and the mean determined. The mean of the three readings shall be taken as the in-situ bulk density (IBD). If the above criterion is not met after six readings, the densometer shall not be used.

(7) The densometer shall be removed and a minimum 500 g sample of the material

directly beneath the densometer position shall be taken for determination of the moisture content. The sample shall be obtained by augering or digging to the test depth. The sample shall be placed in a moisture tight container and the lid replaced. The moisture content (w) shall be determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

(8) If a sample of material at the same location as the densometer test is required for

determination of the maximum dry density or the maximum converted bulk density, the sample shall be obtained by digging to the test depth, keeping the sides of the excavation vertical and the bottom flat and level. The appropriate quantity of material required for the test shall be taken, placed in a moisture tight container and the container sealed.

A7.3.6 Calculation

The in-situ dry density of the material (IDD) shall be calculated from the equation:

IDD = IBD/(1 + w ) Mg/m³

100 where:

- IBD is the in-situ bulk density of the material (Mg/m³) - w is the moisture content of the material (%)


A7.3.7 Reporting of Results The following shall be reported:

(1) the location of the test;

(2) the in-situ dry density to the nearest 0.01 Mg/m³; (3) the moisture content to the nearest 0.1%; and (4) that the test method used was in accordance with this General Materials and



APPENDIX A7.4

DETERMINATION OF THE MAXIMUM CONVERTED BULK DENSITY BY THE HILF METHOD

A7.4.1 Scope This method covers the determination of the maximum converted bulk density and the

difference between the optimum moisture content and the in-situ moisture content of a material by relating the converted bulk density and the moisture added.

A7.4.2 Apparatus The following apparatus is required:

(1) Apparatus in accordance with GEO Report No. 36, Test 4.3.3A or 4.3.3B, whichever

as instructed by the Project Manager.

(2) Apparatus for determination of the moisture content in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix A7.2, whichever as instructed by the Project Manager.

(3) Apparatus to extract specimens from the mould.

(4) Apparatus, such as a warm air blower, for rapid drying of the material.

A7.4.3 Procedure


(1) A sample of material shall be taken immediately after completing the in-situ bulk density test at the same location as the test. The sample shall be obtained by digging to the same depth as that of the in-situ bulk density test, keeping the sides of the excavation vertical and the bottom flat and level. The size of the sample shall be sufficient to yield a minimum of 10 kg after screening over a 20 mm BS test sieve.

(2) The sample shall be weighed to the nearest 0.01 g.

(3) The sample shall be screened over a 20 mm BS test sieve, ensuring that moisture loss

is kept to a minimum and that any free moisture appearing in the containers is worked back into the sample.

(4) The amount retained on the sieve shall be weighed to the nearest 0.01g and expressed

as a percentage of the mass of the sample. If the percentage exceeds 5%, an adjustment for coarse material shall be made in accordance with Appendix A7.5. If the percentage does not exceed 5%, no adjustment is required.

(5) The material to be tested shall be thoroughly mixed and divided by quartering or by

using a riffle box to obtain a minimum of four specimens of at least 2500g each, ensuring that moisture loss is kept to a minimum. Alternatively, if it has previously been ascertained that the material is not susceptible to crushing, a single specimen of at least 2500 g may be used for repeat testing.


(6) Each specimen shall be weighed to the nearest 0.01g and the result shall be taken as the mass of the specimen at the in-situ moisture content.

(7) Each specimen and any remaining material shall be placed in separate moisture-tight

containers and the containers sealed.

(8) The converted bulk density of at least three specimens shall be plotted against the amount of water added or removed as a percentage of the mass of the specimen at the in-situ moisture content (z) on a graph as shown in the Hong Kong Government Civil Engineering Department Standard Drawing No. C2006, in accordance with the procedure stated in Clause A7.4.3(9) to (15).

(9) The first point on the graph shall be obtained as follows:

- A specimen shall be compacted at its in-situ moisture content in accordance

with GEO Report No. 36, Test 4.3.3A, Clause 4.3.3A.4 or Test 4.3.3B, Clause 4.3.3B.4, whichever as instructed by the Project Manager.

- A diametrical slice of approximately 400 g to 500 g shall be cut from the

specimen along its entire length. The in-situ moisture content of the slice (wi) shall be determined in accordance with either GEO Report No. 36, Test 2.3.2A or 2.3.2B or Appendix 7.2, whichever as instructed by the Project Manager.

- The bulk density (BD1) shall be calculated as stated in Clause A7.4.4(1) and

plotted on the 0% ordinate of the graph as the converted bulk density (CBD1).

(10) The second point on the graph shall be obtained as follows: - A second specimen shall be examined and, if the in-situ moisture content

obviously exceeds the optimum moisture content, the procedure stated in Clause A7.4.3(11) shall be followed.

- The moisture content of the specimen shall be increased by adding an amount

of water equal to 2% of the mass of the specimen. The specimen shall be thoroughly mixed and compacted in accordance with the method stipulated in Clause A7.4.3(9).

- The bulk density (BD2) shall be calculated as stated in Clause A7.4.4(1),

adjusted to converted bulk density (CBD2) as stated in Clause A7.4.4(2) and plotted on the +2% ordinate of the graph.

(11) If the in-situ moisture content of the second specimen obviously exceeds the optimum

moisture content, the specimen shall be dried until the amount of water removed is approximately 2% of the mass of the specimen and cooled. The specimen shall be thoroughly mixed and compacted in accordance with the method stipulated in Clause 7.4.3(9). The amount of water removed shall be determined. The bulk density (BD2) shall be calculated as stated in Clause A7.4.4(1), adjusted to converted bulk density (CBD2) as stated in Clause A7.4.4(2) and plotted on the negative ordinate of the graph at a point which corresponds to the amount of water removed.


(12) The third point on the graph shall be obtained as follows: - If the plotted value of CBD2 is equal to or greater than the plotted-value of

CBD1, the moisture content of a third specimen shall be increased by adding an amount of water equal to 4% of the mass of the specimens. Alternatively, if the procedure stated in Clause A7.4.3(11) has been followed, the specimen shall be dried until the amount of water removed is approximately 4% of the mass of the specimen after cooling.

- If the plotted value of CBD2 is less than the plotted value of CBD1, the third

specimen shall be dried until the amount of water removed is approximately 2% of the mass of the specimen after cooling. Alternatively, if the procedure stated in Clause A7.4.3(11) has been followed, the moisture content shall be increased by adding an amount of water equal to 2% of the mass of the specimen.

- The specimen shall be thoroughly mixed and compacted in accordance with the

method stipulated in Clause A7.4.3(9). The amount of water removed shall be determined.

- The bulk density (BD3) shall be calculated as stated in Clause A7.4.4(1),

adjusted to converted bulk density (CBD3) as stated in Clause A7.4.4(2) and plotted on the graph at a point which corresponds to the amount of water added or removed.

(13) If the centre point of the three points plotted is lower than one of the other two points,

or is higher than one point and equal to the other, an additional point or points shall be obtained by proceeding in 2% increments or decrements as appropriate.

(14) If it is apparent that the moisture condition of the material is such that a total of five

points will not result in the determination of the optimum moisture content, increments and decrements of 3% moisture content may be adopted for the entire procedure.

(15) A smooth approximately parabolic curve shall be drawn to the plotted points. The

peak value of the curve shall be determined as the maximum converted bulk density (MCBD).

(16) The amount of water added or removed as a percentage of the mass of the specimen at

the in-situ moisture content corresponding to the maximum converted bulk density shall be determined (zm).

(17) The value of the moisture correction curve passing through the peak value of the

plotted parabolic curve shall be determined (zc). If there is no moisture correction curve passing through the peak value of the curve, a moisture correction curve shall be drawn through the peak by interpolating to the nearest 0.1%.


A7.4.4 Calculation

(1) The bulk density (BD) shall be calculated from the equation:

BD = (m2 - m1)/V Mg/m³

where:

- m1 is the mass of the mould and base (g) - m2 is the mass of the mould, base and wet material (g) - V is the volume of the mould (mL)

(2) The converted bulk density (CBD) shall be calculated from the equation:

CBD = BD/(1+z/100) Mg/m³

where:

- z is the amount of water added or removed as a percentage of the mass of the

specimen at the in-situ moisture content - z is negative for values below the in-situ moisture content

(3) The difference between the optimum moisture content (wo) and the in-situ moisture content (wi) of the material shall be calculated from the equation:

wo - wi = zm + zc % where: - zm is the amount of water added or removed as a percentage of the mass of the

specimen at the in-situ moisture content corresponding to the maximum converted bulk density (%)

- zc is the value of the moisture correction curve passing through the peak value

of the plotted parabolic curve (%)

(4) The optimum moisture content (wo) shall be calculated from the equation:

wo = wi + (1 + wi/100) zm % where: - wi is the in-situ moisture content of the material (%)

(5) The maximum dry density (MDD) shall be calculated from the equation:

MDD = MCBD/(1 + wi/100) Mg/m³

where:

- MCBD is the maximum converted bulk density of the material (Mg/m³)


(6) The relative compaction (RC), if required, shall be calculated from the equation:

RC = IBD/MCBD x 100% where: - IBD is the in-situ bulk density of the material determined in accordance with

GEO Report No. 36, Test 9.2.1 or 9.2.2 as appropriate to the grain size of the material or in accordance with Appendix A7.3


The following shall be reported;

(1) source and identification of the soil; (2) the graph showing the plotted points and the parabolic curve passing through them;

(3) the maximum converted bulk density to the nearest 0.01 Mg/m³; (4) the optimum moisture content to the nearest 0.1%;

(5) the maximum dry density to the nearest 0.01 Mg/m³; (6) the relative compaction to the nearest 0.1%, if determined; (7) the percentage retained on the 20 mm BS test sieve and the percentage retained on the

37.5 mm BS test sieve to the nearest 1%, if applicable; (8) whether the test was carried out using individual specimens or repeat testing of a

single specimen; (9) whether a manual or an automatic compaction rammer was used; and (10) that the test method used was in accordance with this General Materials and



APPENDIX A7.5

ADJUSTMENT OF THE MAXIMUM CONVERTED BULK DENSITY FOR THE DETERMINATION OF THE RELATIVE COMPACTION

A7.5.1 Scope

This method covers the adjustment of the maximum converted bulk density determined in accordance with Appendix A7.4 for the determination of the relative compaction of a material containing more than 5% of the mass of the material at the in-situ moisture content retained on a 20 mm BS test sieve.

A7.5.2 Apparatus


(1) Apparatus in accordance with Appendix A7.4.

(2) A 20 mm and a 37.5 mm BS test sieve.

(3) A mould with collar as used for determination of the California Bearing Ratio (CBR mould).

(4) An extrusion device as used for determination of the California Bearing Ratio.

A7.5.3 Procedure


(1) If the amount of material retained on the 20 mm BS test sieve exceeds 5% and does not exceed 20%, the material passing the sieve shall be compacted in accordance with Appendix A7.4. The maximum converted bulk density (MCBD20) shall be determined and adjusted as stated in Clause A7.5.4.

(2) If the amount of material retained on the 20 mm BS test sieve exceeds 20%, the

retained material shall be screened over the 37.5 mm BS test sieve. The procedure stated in either Clause A7.5.3(3) or Clause A7.5.3(4) as appropriate shall be followed.

(3) If the amount of material retained on the 37.5 mm BS test sieve does not exceed 5%,

the procedure stated in Clause A7.5.3(5) shall be followed.

(4) If the amount of material retained on the 37.5 mm BS test sieve exceeds 5% and does not exceed 20%, the retained material shall be replaced with an equal mass of material which is of a similar nature and which is retained on a 20 mm BS test sieve but passes a 37.5 mm BS test sieve. The procedure stated in Clause A7.5.3(5) shall be followed.

(5) The procedure stated in Appendix A7.4 shall be followed except that the material

shall be compacted into the CBR mould and each layer shall be subjected to 62 blows of the rammer.


A7.5.4 Calculation

The maximum converted bulk density (MCBD) shall be calculated from the equation:

MCBD = MCBD20 [1 + m (1 - MCBD20)] Mg/m³

1 + z Gs 100

where: - MCBD20 is the maximum converted bulk density of the material passing the 20 mm

BS test sieve (Mg/m³) - z is the amount of water added as a percentage of the mass of the specimen at the in-

situ moisture content corresponding to the maximum converted bulk density (%) A7.5.5 Reporting of Results


(1) the source and identification of the soil;

(2) the results in accordance with Appendix A7.4;

(3) the mass of the original material not passing the 20 mm and 37.5 mm BS test sieve as a percentage of the mass of the material at the in-situ moisture content to the nearest 0.1%;

(4) the type of mould used;

(5) the number of blows per layer;

(6) whether the specific gravity was measured or assumed and, if measured, the method

used; and

(7) that the test method used was in accordance with this General Materials and Workmanship Specification, and the results have been adjusted in accordance with this Appendix.


SECTION 8 GEOTECHNICAL WORKS 8.1 GENERAL REQUIREMENTS

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section:

(a) Site clearance shall comply with Section 3.

(b) Drainage works shall comply with Section 6.

(c) Earthworks shall comply with Section 7.

(d) Concrete shall comply with Section 20.

8.2 TRIALS FOR GEOTECHNICAL WORKS

(a) Details of trials to be carried out for geotechnical works shall be as stated in the Contract.

(b) The trials shall be carried out to demonstrate that the proposed materials and methods

of construction will produce work which complies with the specified requirements.

(c) Trials shall be carried out in sufficient time before commencement of the relevant Permanent Works starts to allow the Project Manager a sufficient period to determine if the trial complies with the specified requirements.

(d) The Contractor shall notify the Project Manager before the trial starts.

(e) Trials shall be carried out using the materials and methods of construction submitted

to the Project Manager for review. Trials shall be carried out at locations reviewed without objection by the Project Manager.

(f) If work which complies with the specified requirements has not been produced in the

trial, particulars of proposed changes to the material or methods of construction shall be submitted to the Project Manager for review; further trials shall be carried out until work which complies with the specified requirements has been produced in the trial.

(g) Geotechnical works for which trials are required shall not commence until work

which complies with the specified requirements has been produced in the trial.

(h) The material and methods of construction used to produce work which complies with the specified requirements in a trial shall not be changed.

8.3 DEFINITIONS AND ABBREVIATIONS - GROUND INVESTIGATION 8.3.1 Block sample

Block sample is an undisturbed sample recovered by in-situ hand trimming of a block of material from the surrounding soil.


8.3.2 Bulk sample Bulk sample is a sample of at least 10 kg mass which is representative of the grading of the material at the point of sampling.

8.3.3 Inspection pit

Inspection pit is a pit for locating and identifying underground utilities and structures. 8.3.4 Jar sample

Jar sample is a disturbed sample of at least 0.7 kg mass contained in a transparent airtight jar which has a screw cap with an airtight sealing ring.

8.3.5 Mazier sample

Mazier sample is an undisturbed sample recovered by rotary drilling using a Mazier triple tube core barrel which has inner tubes protruding proud of the outer tube to protect the material being sampled from disturbance.

8.3.6 Sample

Sample is any quantity of material obtained from the ground for the purposes of inspection, logging or testing.

8.3.7 Slope surface stripping

Slope surface stripping is the removal of surface protection and vegetation from existing slopes to expose underlying soil or rock for inspection.

8.3.8 Trial pit

Trial pit is a pit for inspecting and logging the ground and in which to carry out in-situ testing and sampling.

8.3.9 U 100 and U 76 samples U 100 and U 76 samples are undisturbed samples recovered by advancing a thin-walled tube

with a cutting edge into the soil. 8.3.10 Undisturbed soil sample Undisturbed soil sample is a sample complying with Class 1 or Class 2 of BS 5930. 8.4 SUBMISSIONS – GROUND INVESTIGATION 8.4.1 Particulars of ground investigation

The following particulars of proposed materials and methods for ground investigation shall be submitted to the Project Manager for review:

(a) details of drilling and in-situ testing equipment;


(b) details of sampling equipment; and (c) details of filter materials and fill materials for drilling and testing,

8.5 WORKMANSHIP - GROUND INVESTIGATION 8.5.1 Inspection pits Inspection pits shall be formed by manual methods. 8.5.2 Trial pits

(a) The plan dimensions at the bottom of a trial pit shall be at least 1.2 m x 1.2 m and the sides of trial pits shall be vertical.

(b) The sides of trial pits shall be trimmed by manual methods to remove all disturbed

material. Supports to the sides of trial pits shall be such that the cut surface is clearly visible throughout the height of each face.

(c) The Project Manager shall be notified before fill material is deposited in trial pits.

8.5.3 Slope surface stripping (a) Slope surface stripping shall start at the top of the slope and shall proceed downwards.

All loose material remaining on the slope after stripping shall be removed. (b) Access shall be provided for inspection by the Project Manager. (c) Stripped areas shall be covered up at the end of each working day and during

rainstorms to prevent the ingress of water into the slope. (d) Stripped areas shall be reinstated in form, colour and conditions similar to the

original. The Project Manager shall be notified before reinstatement starts. 8.5.4 Records of inspection pits Records of inspection pits shall be kept by the Contractor on Site and a report shall be

submitted to the Project Manager for review within 3 days after each inspection pit has been excavated. The report shall contain details of the positions, depths and dimensions of all utilities and structures encountered in each inspection pit.

8.5.5 Records of trial pits and slope surface stripping

(a) Each trial pit shall be photographed as soon as excavation is complete. The full face of each of the sides and the bottom of the trial pit shall be photographed individually. One copy of specimen prints of 127 mm x 76 mm size shall be submitted to the Project Manager for review before fill material is deposited in the trial pit. The photographs shall contain the following information:

(i) number of trial pit and site reference;

(ii) measuring scale bar; and

(iii) a suitable colour comparison chart placed alongside the trial pit face.


(b) Records of trial pits shall be kept by the Contractor on Site and a report shall be submitted to the Project Manager for review within 24 hours after each trial pit has been excavated. The report shall contain the following:

(i) details shown, and in the format shown in Figure 7 of `Geoguide 2 : Guide to

Site Investigation', Hong Kong Government 1987;

(ii) details of depths and rate of groundwater seepage;

(iii) details of water levels, including dates and details of fluctuation; and

(iv) four sets of photographs or composite photographs as stated in Clause 8.5.5(a); the photograph of each face shall occupy the full height of an A4 size page.

(c) Records of slope surface stripping shall be kept by the Contractor on Site and a report

shall be submitted to the Project Manager for information within 24 hours of the surface stripping. The report shall contain a detailed geological description of the materials exposed, and details and locations of groundwater seepage.

8.5.6 Drilling rigs for ground investigation

(a) Drilling rigs for ground investigation shall be the hydraulic feed type and shall have a rating of at least 26.5 kW to drive a rotary tool tipped with diamonds or tungsten carbide. Drilling rigs shall be capable of drilling in the specified sizes and to the specified depths without excessive vibration.

(b) The weight of each rig shall be such that a force of 12 kN can be applied to the

drilling bit without movement of the rig.

(c) Drilling rigs shall be capable of providing stable drill-string rotation at speeds of between 50 rpm and 1250 rpm and have a ram stroke length of at least 600 mm. The rigs shall be fitted with a tachometer and a hydraulic feed pressure gauge, both of appropriate scales, and a device for measuring the rate of penetration of the drill strings.

(d) Triplex or similar type pumps shall be used when the flushing medium is water; the

pumps shall be equipped with a gear box and shall be capable of delivering up to 2 L/s. The pumps shall incorporate a surge bottle to reduce fluctuations in water pressure and the suction hose shall be fitted with a suitable filter. The pumps shall have a by-pass system allowing full control of water flow at all pump delivery rates.

8.5.7 Drilling equipment for ground investigation

(a) Spare drill bits shall be available for use during drilling.

(b) The size of casings shall be appropriate to the drilling, coring, sampling, testing and other installation requirements.

(c) Core barrels for sampling soil shall be equipped with a sediment catcher tube. The

tube shall have the same external diameter as the core barrel and shall be approximately 0.75 m long.


(d) Casings shall be used to stabilize caving ground. The size of casing and drill rod in use shall be appropriate to the size of core barrel in use. Casings and drill rods shall be straight and shall be clean at the time of drilling and free from scale, dirt and other loose material.

(e) Only regular lengths of casings and drill rods shall be used and imperial and metric

lengths shall not be mixed.

(f) Short lengths of drill rods shall be used to enable continuous coring to be carried out in such a manner that each core run can be completed within one ram stroke.

(g) Short lengths of casing not exceeding the ram stroke length shall be used to enable

casings to be advanced after each core run where necessary.

(h) Core barrels and drill rods shall be stored on steel frame trestles. 8.5.8 Drilling for ground investigation

(a) Drillholes for ground investigation shall be sunk by rotary methods. The methods and equipment used shall be such that:

(i) the overall hole alignment is within 2% for vertical drillholes and is within 5%

of the specified alignment for non-vertical drillholes;

(ii) the soil encountered and the levels at which changes in ground conditions occur can be accurately identified;

(iii) the specified sampling requirements can be achieved;

(iv) in-situ tests can be carried out and field installations can be incorporated at any

depth in the drillhole; and

(v) consistency of measurement and minimal disturbance of the ground is achieved.

(b) Casings shall be advanced concurrently with the removal of material in such a manner

that loss of ground is avoided.

(c) Larger casings shall be set concentric with drillholes which are being reamed.

(d) The flushing medium for drilling shall be clean water, air, air mist or air foam; other substances or materials shall not be introduced into drillholes. The flushing medium for drilling shall be passed through a sedimentation basin and shall either be reused or be discharged to surface drains or natural stream courses. Measures shall be taken to prevent flushing mediums seeping through the ground.

(e) The flushing medium for drilling shall not be discharged to stream courses which are

used as a supply of drinking water.


8.5.9 Sampling from drillholes

(a) Jar samples from drillholes shall be taken from the cutting shoe of each undisturbed sample, from any anomalous material, from each standard penetration test and at other locations as directed by the Project Manager.

(b) All loose material and material disturbed by drilling or in-situ tests shall be removed

from the sides and bottom of the drillhole before each undisturbed sample is taken. 8.5.10 Filling drillholes

(a) Granular fill material of a type reviewed without objection by the Project Manager, or 4:1 cement bentonite grout where directed by the Project Manager, shall be deposited in drillholes for ground investigation and compacted to the same relative compaction as the surrounding ground. The casing shall be gradually withdrawn; the fill material shall be kept above the bottom of the casing during withdrawal. Subsequent depressions in the ground surface shall be filled and reinstated. The drillhole position shall be marked with a metal marker and flag or a 300 mm x 300 mm x 150 mm thick concrete block; the hole number shall be inscribed on the surface and highlighted in red paint.

(b) The Project Manager shall be notified before fill material is deposited in drillholes

and before the casing is withdrawn. The ground surface around drillholes shall be reinstated as soon as practicable after the fill material has deposited and compacted in each drillhole.

8.5.11 Records of drillholes

(a) Records of drillholes for ground investigation shall be kept by the Contractor on Site and two copies of a preliminary drillhole log, stamped PRELIMINARY, shall be submitted to the Project Manager for review within 24 hours after completion of each drillhole. Drillhole logs shall be comprehensive and shall be in a form similar to that shown in Figure 44 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987; soil and rock descriptions shall comply with those stated in the insert titled 'Checklist for Soil Descriptions' and 'Checklist for Rock Descriptions' in 'Geoguide 3 : Guide to Rock and Soil Descriptions', Hong Kong Government, 1988.

(b) Drillhole logs shall be drawn to a constant vertical scale of 1:50 and shall contain the

following details:

(i) information shown and in the format in Figure 44 and Paragraphs 40.2.6 (2), (4) and (5) of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987;

(ii) reduced levels of groundwater strike, observation well bases, piezometer tips,

and sand filter layers; and

(iii) details of utilities identified in the inspection pit excavated at the drillhole location.


8.5.12 Sampling equipment for ground investigation

Sampling equipment and containers for ground investigation shall comply with BS5930 and the following :

(a) For general purpose open tube samples and thin-walled samples, the sample tube and

cutting shoe shall be free from rust, pitting, burring or any other defect. The use of oil inside the sampler shall be limited to the minimum practical. Each sample tube shall have a unique reference number and the word 'TOP' engraved on its exterior at one end. The sample tube shall be driven with the end marked 'TOP' uppermost. The dimensions, construction and condition of each sample tube, cutting shoe and adaptor head shall be reviewed by the Project Manager prior to sampling. The adaptor head shall be fitted with a ball valve to permit the exit of air or water during driving and to assist in retaining the sample during withdrawal, and it shall have an allowance for over-driving. In soil of low cohesion such as silts and silty fine sands the sampler shall be equipped with a basket core retainer to enhance core recovery.

(b) U100, U76 and U40 thin-walled samplers shall be 102 mm (for U100), 78 mm (for

U76) and 42 mm (for U40) diameter open drive sample tubes made from thin-walled seamless cadmium plated or stainless steel not less than 450 mm (for U100), 350 mm (for U76) and 200 mm (for U40) in length fitted with a cutting shoe tapered at an angle not exceeding 20º. The area ratio of the sampler as defined in Figure 13 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987 shall not exceed 30%.

(c) Piston samplers shall be a thin-walled fixed piston sampler. The piston sampler shall

be capable of operating to a depth of at least 20 m below ground level with no lateral movement during the actual sampling operation. The design and maintenance of the sampler shall be such that a partial vacuum is formed over the retained sample in the tube. The minimum recovered sample length shall be 900 mm. The thin-walled tube shall have an external diameter of 75 mm or 100 mm as directed by the Project Manager. The area ratio of the sampler as defined in Figure 13 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987 shall not exceed 10%.

(d) Mazier samplers shall be a Mazier triple-tube core barrel fitted with a detachable rigid

PVC inner tube, 2 mm thick, 74 mm internal diameter by 1000 mm long having a detachable projecting cutting shoe which perforates the soil and insulates the core sample from the drilling fluid. The internal diameter of the projecting shoe should not differ by more than 2 mm. The dimensions of the sampler shall not differ by more than ±0.50 mm from those shown in Table 8.1 basket core retainer shall be fitted at the bottom of the PVC inner tube to assist in recovery of the core. The length of the sample recovered shall not be less than 750 mm. A triple-tube core barrel of alternative design shall be submitted for the Project Manager's review.


(e) Split spoon samplers for the standard penetration test shall be provided with a thin smooth stainless steel.

Table 8.1: Dimensions of Mazier Core Barrel Sampler

Item Dimension (mm) Inner Barrel Cutting Shoe ID OD

72.0 77.2

Core bit OD 101.1 Liner tube ID 74.0 Inner tube barrel ID OD

78.0 88.5

Outer tube barrel OD 98.5 8.5.13 Sampling for ground investigation

(a) A reference number shall be assigned to each soil sample taken from a drillhole or trial pit. The number shall be unique for that drillhole or trial pit and shall be in order of depth below ground level.

(b) The visible ends of each undisturbed sample shall be trimmed of any disturbed

material immediately after recovery from the ground. The sides of the tube or box shall be cleaned and the ends of the sample shall be coated with three successive thin films of just-molten microcrystalline wax. A metal foil disc or plate shall be added and followed by more molten wax to give a total thickness of at least 20 mm. Any space remaining in the ends of the sample tube or box shall be solidly filled with damp sawdust and the ends of the sample tube shall be covered with tight fitting rubber caps.

(c) Each sample shall be identified by a label. The label shall be written with permanent

ink and protected from moisture, damage and loss. The minimum labelling requirements shall be as follows:

(i) All labels shall contain the following information:

- name of Contract; - name or reference number of the site; - reference number, location and angle of borehole; - reference number of sample; - date of sampling; - brief description of the sample; - depth of the top and the bottom of the sample below ground level; and - location and orientation of the sample if taken from a trial pit.

(ii) For jar samples, a stick-on label covered with a transparent plastic cover shall

be secured with adhesive tape to the body of the jar.

(iii) For undisturbed and bulk samples, a permanent or stick-on label covered with a transparent plastic sheet shall be secured with adhesive tape to the body of the container. An additional label giving the sample reference number and depth of sample shall be sealed in with the sample.

(iv) For core samples stored in core boxes, a stapled card, stick-on label or

permanent ink shall be used externally on the front of the box and repeated inside. The hole reference number shall be written in permanent ink or paint on each end of the core box.


8.5.14 Storage and delivery of samples for ground investigation

(a) Samples for ground investigation shall be delivered to, and stored at, a core store at a location reviewed without objection by the Project Manager. Samples shall be delivered to the testing laboratory at a time reviewed without objection by the Project Manager.

(b) Undisturbed soil samples shall be stored and delivered in a wooden crate of

appropriate dimensions. The samples shall be kept in an upright position with a separate compartment for each sample. The compartment shall be properly padded and the lower end of the sample shall be placed in the bottom of the compartment.

(c) The samples shall not be disturbed during transportation, handling and storage.

8.5.15 Bulk samples Bulk samples shall be obtained from undisturbed ground. Each bulk sample shall be sealed

into a metal or plastic container immediately after it has been taken. 8.5.16 Mazier samples Mazier samples shall be taken by a Mazier sampler and in accordance with Clause 8.5.12. 8.5.17 U100 and U76 samples

(a) Sample tubes shall be advanced by jacking action. The jack shall be arranged to align with the sampler. Measures shall be taken to prevent lateral movement during the sampling operation.

(b) Each U100 sample shall contain at least 300 mm net length of undisturbed material

and each U 76 sample shall contain at least 200 mm net length of undisturbed sample. 8.5.18 Block samples

(a) Block samples shall be taken from the sides or bottom of trial pits at locations and orientations determined by the Project Manager.

(b) Each block sample shall be at least 230 mm x 230 mm x 230 mm and shall be

excavated, trimmed, cut, wrapped, waxed and packed in metal or wooden boxes in accordance with the procedure stated in Part A of Des. E-2 of the United States Bureau of Reclamation Earth Manual.

8.5.19 Rock cores

(a) Rock cores obtained from drillholes shall be removed from the core barrel without damage by gentle hammering with a wooden mallet on the side of the core barrel to free wedges pieces; other methods shall not be used.

(b) As the rock core is extruded, it shall be arranged in the box in sequence starting with

the shallowest core on the left side of the box against the hinge and working along the slat and subsequently outwards towards the staple. The depths at which each core run started and finished shall be recorded within the box by painting on wooden blocks which fit between the dividing slats. Fractured rock core shall be spread throughout its length and packed securely. Rock core losses shall be shown by wooden blocks or polystyrene of a square cross section to fill the core box; the length of the wooden block or polystyrene shall be equal to the length of core lost.


8.5.20 Standard penetration tests

(a) The apparatus and procedure for standard penetration tests shall comply with BS1377:1975, Test 19. The drive hammer shall be a type incorporating an automatic trip mechanism to ensure free fall. The 60º solid core shoe shall be used in soil containing coarse gravel.

(b) A thin smooth stainless steel or aluminum liner of 35 mm internal diameter shall be

fitted in the split-spoon sampler during the standard penetration test. After the sampler has been withdrawn from the drillhole, the liner and the retained soil shall be treated in the same manner as an undisturbed sample.

(c) Standard penetration tests shall be carried out below the level of the casing. The base

of the drillhole shall be fully cleaned before the test starts. Jar samples shall be taken from the split-barrel shoe after each test.

(d) The number of blows of the drive hammer required to achieve each 75 mm of shoe

penetration until a total penetration of 450 mm has been achieved shall be recorded. The N-value shall be recorded as the sum of the number of blows of the drive hammer required to achieve the last 300 mm of shoe penetration. The number of blows recorded for the initial 150 mm of shoe penetration shall not be included in the N-value calculation. If any increment of 75 mm of shoe penetration is not achieved after 100 blows of the drive hammer, the number of blows and the penetration achieved shall be recorded and the test shall be terminated.

8.5.21 GEO probe tests

GEO probe tests shall be carried out in accordance with Appendix A8.1. The GEO probe hole shall be sealed with cement grout on completion of the test for at least the top 600 mm of the hole. The grout shall consist of cement and water in the proportions 0.4:1 by mass.

8.5.22 In-situ density tests

(a) In-situ density tests shall be carried out by the sand replacement method in accordance with Clause 7.5.14 (e) and (f).

(b) A jar sample shall be taken at each location where an in-situ density test is carried out.

8.5.23 Rising and falling head permeability tests

(a) Rising and falling head permeability tests shall be carried out using the apparatus described in Figure 27 of 'Geoguide 2: Guide to Site Investigation', Hong Kong Government, 1987. The method of testing shall be in accordance with Figure 30 of 'Geoguide 2: Guide to Site Investigation', the method of flushing of the bottom of the drillhole stated in Clause 8.5.23(d) shall be used. The type of filter material and sand to be used shall be in accordance with Clause 8.24.10(b), and shall be placed in the drillhole using a tremie pipe.

(b) Rising head permeability tests shall be carried out by lowering the water level in the

standpipe by approximately 3 m. The water level in the standpipe shall be allowed to rise to equalise with the ground water level and the time for each 0.2 m rise in water level shall be recorded.

(c) Falling head permeability tests shall be carried out by raising the water level in the

standpipe by approximately 3 m. The water level in the standpipe shall be allowed to fall to equalise with the ground water level and the time for each 0.2 m drop in water level shall be recorded.


(d) The method of flushing of the bottom of the hole for field permeability tests shall be as follows:

(i) Clean water shall be introduced to the cased hole through a 38 mm diameter

pipe fed from a storage tank. The feed pipe shall contain a perforated section 480 mm in length consisting of 20 rings of holes, at 25 mm centres, each containing 4 holes of 6 mm diameter. The complete perforated section shall be positioned such that it is just below the existing ground water level in the borehole. The end of the perforated section of pipe shall be capped.

(ii) The flushing water shall be withdrawn from the casing through a 38mm

diameter pipe positioned with its open end between 150 mm and 200 mm above the base of the borehole. The discharge shall be by means of a pump of sufficient capacity to extract the flushing water from the base of the borehole. Control of the flow of clean water and discharge water shall be by means of valves positioned on the inflow pipe and the discharge pipe.

8.5.24 Constant head permeability tests

(a) Constant head permeability tests shall be carried out using the apparatus described in Clause 8.5.23(a). Clean water shall be fed into the standpipe at a constant rate and the time for each 0.2 m rise in water level shall be recorded until either a constant water level is established or until the water level is 0.3 m below the top of the casing. The constant rate of inflow which is required to maintain a constant head shall be recorded.

(b) After a constant water level has been achieved as stated by Clause 8.5.24(a), the

cumulative inflow readings required to maintain the constant head shall be recorded in the following sequence:

(i) 4 readings at 15 second intervals;

(ii) 9 readings at 1 minute intervals;

(iii) 4 readings at 5 minute intervals; and

(iv) readings at 10 minute intervals until two consecutive readings differ by less

than 0.5 litre. 8.6 INSPECTION, TESTING AND COMMISSIONING – GROUND INVESTIGATION 8.6.1 Records of in-situ testing

(a) Records of each in-situ test shall be kept by the Contractor on Site. The Project Manager shall be notified before test apparatus is dismantled.

(b) The results of standard penetration tests shall be recorded on drillhole logs as stated in

Clauses 8.5.11 and 8.6.2. (c) The results of GEO probe tests shall be recorded as stated in Clause 8.5.21 and shall

be submitted to the Project Manager for review within 24 hours after the test. (d) The results of in-situ density tests shall be recorded in a form reviewed without

objection by the Project Manager and shall be submitted to the Project Manager for review within 24 hours after the test.


(e) The results of rising, falling and constant head permeability tests shall be recorded as stated in Clauses 8.5.23 and 8.5.24 and shall be submitted to the Project Manager for review within 24 hours after the test. The results of the rising and falling head permeability tests shall be recorded in the format shown in Figure 30 of 'Geoguide 2 : Guide to Site Investigation', Hong Kong Government, 1987.

8.6.2 Reports for ground investigation

(a) Daily records of ground investigation operations shall be kept by the Contractor on Site and two copies of the records shall be submitted to the Project Manager for review within 3 days after the ground investigation operation to which they refer. The daily records shall contain the following information in a form reviewed without objection by the Project Manager:

(i) Contractor's name, and Contract number, borehole reference number and

inclination, site name, rig type and number, operator, hours worked with times, date, weather, ground level at borehole and measured water levels in the borehole at various times;

(ii) for each sample, drilling or core run for each test, installation or strata

encountered, the following where applicable: - start and finish depths below ground level; - start and finish times; - casing diameter and depth; - bit number and type; - sample reference number and type; - SPT test result in number of blows recorded; - percentage water returns and core recovery; - a description of the soil and rock strata or sample; and - a description of field tests or instruments installed.

(b) A final report on ground investigation operations shall be prepared by the Contractor

and shall be submitted to the Project Manager for review within 15 days after all comments on the preliminary drillhole logs have been received from the Project Manager. The report shall contain the drillhole logs and test records.

8.7 MATERIALS - SLOPE TREATMENT WORKS 8.7.1 Cement mortar

(a) Cement mortar for in-filling joints in rock faces, for bedding rock for masonry infilling and for surfacing slopes shall consist of OPC and sand in the proportions 1:3 by volume.

(b) OPC shall comply with BS 12. (c) Sand shall be natural sand or crushed natural stone complying with BS 1200.

8.7.2 Rock for masonry infilling

Rock for masonry infilling shall not exceed 300 mm in size and shall be obtained from a source reviewed without objection by the Project Manager.


8.7.3 Soil-cement (a) Soil-cement shall consist of OPC, sand and inorganic soil in the proportions 1:3:12 by

mass. (b) OPC shall comply with BS 12. (c) Sand shall comply with BS 1200. (d) Inorganic soil shall be free from organic matter and shall contain not more than 30%

of soil particles passing a 63 m BS test sieve.

8.7.4 Chunam

(a) Chunam for surfacing shall consist of OPC, hydrated lime and inorganic soil in the proportions 1:3:20 by mass.

(b) OPC shall comply with BS 12. (c) Hydrated lime shall comply with BS 890, Type 1. (d) Inorganic soil shall be as stated in Clause 8.7.3(d).

8.7.5 Aggregates for sprayed concrete

The nominal maximum aggregate size of aggregates for sprayed concrete shall not exceed 10 mm.

8.7.6 Reinforcement for sprayed concrete

Fabric reinforcement for sprayed concrete shall comply with BS 4483. 8.7.7 Protective mesh and fixings

(a) Protective mesh for slopes shall be PVC coated galvanized steel wire woven into a double twist hexagonal mesh; each hexagon shall be 80 mm x 60 mm. The steel wire shall be at least 2.2 mm diameter and the PVC coating shall be at least 0.4 mm thick.

(b) Tying wire for protective mesh shall be 2.2 mm diameter PVC coated galvanized soft

annealed steel wire. (c) Bolts for fastening protective mesh to rock shall be galvanized mild steel hooks as

stated in the Contract. (d) Bolts for permanent protective screens shall be galvanized to a minimum average

mass coating of 610 g/m². (e) Galvanizing shall comply with BS 729.

8.7.8 Rock bolts

(a) Rock bolts shall be a proprietary type reviewed without objection by the Project Manager. Rock bolts shall comply with CS2 and shall be mild steel or high yield deformed steel as stated in the Contract. Rock bolts shall be galvanized to a

minimum average mass coating of 610 g/m² in accordance with BS 729.


(b) The rated working load of rock bolts shall not exceed 50% of the ultimate tensile strength. A reduction of 4 mm in the diameter of the bolt shall be taken into account for corrosion when calculating the ultimate tensile strength.

8.7.9 Grout for rock bolts

Grout for rock bolts shall be as stated in Clauses 8.11.2 and 8.14.5 except that the water cement ratio shall not exceed 0.45.

8.7.10 Rock dowels

Rock dowels shall comply with CS2 and shall be high yield deformed steel as stated in the Contract.

8.7.11 Grout for rock dowels

Grout for rock dowels shall be as stated in Clauses 8.11.2 and 8.14.5 with a water cement ratio not greater than 0.45.

8.8 SUBMISSIONS – SLOPE TREATMENT WORKS 8.8.1 Particulars of access

Particulars of the proposed means of access for slope treatment works, including access structures and reinstatement, shall be submitted to the Project Manager for review.

8.8.2 Particulars of sprayed concrete

(a) The following particulars of the proposed materials and methods of construction shall be submitted to the Project Manager for review:

(i) type and performance of mixing and spraying plant;

(ii) details of water sprays and associated pumps for surface spraying;

(iii) method of curing;

(iv) details of trial panels and test panels;

(v) methods of measuring surface temperature and moisture content of the soil; and

(vi) methods of achieving the specified thickness of sprayed concrete and the

specified cover to reinforcement and methods of measuring the thickness and cover after spraying.

8.8.3 Particulars of rock bolts

(a) The following particulars of the materials and methods of construction for rock bolts shall be submitted to the Project Manager for review:

(i) details of rock bolts, anchorages and centralizers;

(ii) methods of tensioning and grouting;

(iii) proposed working loads;


(iv) previous performance records; and

(v) details of equipment for testing rock bolts, including test and calibration certificates.

8.8.4 Representative samples of materials

A representative sample of a complete rock bolt shall be submitted to the Project Manager for review of the source and type of rock bolt at the same time as particulars of rock bolts are submitted.

8.9 WORKMANSHIP – SLOPE TREATMENT WORKS 8.9.1 Access to slopes

(a) Means of access consisting of materials reviewed without objection by the Project Manager shall be installed to enable the Project Manager to examine slope treatment works. The means shall allow access to within 0.8 m of the slope face; hand and foot holds for climbing shall be provided by members at centres not exceeding 0.5 m vertically and 0.8 m horizontally.

(b) A system of safety ropes shall be installed on the means of access; safety ropes shall

be 12 mm diameter and shall have a breaking force of at least 22 kN. The system of safety ropes shall consist of:

(i) vertical ropes at not more than 3 m centres horizontally securely anchored to

the crest of the slope; and

(ii) horizontal ropes at not more than 3 m centres vertically. The system of safety ropes shall be constructed in such a manner that the ropes are tied at not more than 3 m spacings in both directions to form a net.

8.9.2 Protection fences and barriers

(a) Protection fences and barriers for slope treatment works shall be constructed as stated in the Contract before slope treatment work starts.

(b) Damage to protection fences and barriers shall be repaired immediately. The

Contractor shall notify the Project Manager before protection fences and barriers are dismantled.

8.9.3 Preparation for slope treatment works

(a) Vegetation shall be cleared and existing impermeable surfaces and topsoil shall be removed from existing soil slopes before slope treatment works start.

(b) Loose material shall be removed from the surface of new soil slopes and the surface

shall be trimmed and scarified before slope treatment works start. The surface shall be moistened immediately before the slope surface treatment works start.


(c) Rock faces and joints, and the surface and joints of retaining walls shall be cleaned of moss, vegetation and loose material, immediately before slope treatment works start, and surplus water shall be removed by an air jet. Water flowing from or across the rock face shall be diverted by relief drains before the application of impermeable surfaces. All vegetation and loose material shall be removed from rock joints. Moss and loose materials shall be removed by wire brushing or scraping.

8.9.4 Scaling and trimming of rock slopes

(a) Scaling and trimming of rock slopes shall be carried out in such a manner that soil and rock is removed from the slope face without affecting the stability and integrity of the slope. Measures shall be taken to prevent uncontrolled falls of debris arising from scaling and trimming works. Scaling and trimming of rock slopes shall be carried out using hand-held tools, pneumatic tools or feather and wedge.

(b) All material removed or excavated by scaling and trimming and loose fragments of

soil and rock shall be removed from the slope. Rock faces shall be cleaned using a water jet coupled to compressed air after scaling and trimming is complete.

8.9.5 Rock splitting

Rock splitting shall be carried out using percussive hammers, drills, hydraulic splitters, chemical expanding agents or hand-tools. Explosive shall not be used.

8.9.6 Removal of boulders

Boulders which are to be removed from slopes shall be broken down by means of line drilling, expansive grouts or rock breakers. Explosives shall not be used.

8.9.7 Sealing and infilling & rock joints

Joints in rock faces shall be sealed with Grade 20/20 concrete, cement mortar or masonry. Rock for masonry infilling shall be bedded in cement mortar. Relief drains directed by the Project Manager shall be installed before rock joints are sealed or infilled.

8.9.8 Concrete buttresses

(a) Concrete for buttresses shall be Grade 20/20 unless otherwise stated in the Contract. (b) Drainage which is required behind buttresses shall consist of relief drains connected

to 50 mm diameter PVC outlet pipes laid at a gradient of at least 1 in 50; the PVC pipes shall be securely fixed to the formwork before concreting starts.

8.9.9 Mixing soil-cement

Soil-cement shall be thoroughly mixed in a concrete mixer; small quantities of soil-cement shall not be hand mixed. The constituents of the mix shall be as reviewed without objection by the Project Manager on the basis of the results of field trials.

8.9.10 Deposition and compaction of soil-cement fill

(a) Soil-cement fill shall be deposited in its final position and compacted within 30 minutes after the cement has been added to the mix.


(b) Soil-cement fill shall be compacted as stated in Clauses 7.4.26 and 7.4.29, using the layer thickness and compactive effort successfully demonstrated in the field trials and reviewed without objection by the Project Manager.

(c) The moisture content of the soil cement mix shall not be less than the optimum value

as determined by the vibrating compaction method of BS 1924 : Part 2, nor more than 2% above this optimum value.

(d) The relative compaction of the soil cement fill will be as reviewed without objection

by the Project Manager following review of the results of the field trials, but in any case will not be less than 95% of the maximum dry density for the agreed mix as determined by the vibrating compaction method of BS 1924 : Part 2.

(e) The in-situ density of compacted soil cement fill shall be determined using the sand

replacement method of BS 1924 : Part 2. 8.9.11 Mixing chunam

The cement and lime for chunam shall be mixed dry before adding the soil. The materials shall then be mixed thoroughly, with water sprinkled, until the colour and consistency are uniform.

8.9.12 Placing and compacting chunam (a) Bamboo dowels shall be driven into the face of the slope on which chunam will be

placed at 1.5 m centres on a staggered pitch to leave a 25 mm projection from the slope face to receive the chunam. Bamboo dowels shall be at least 25 mm in diameter and shall be 150 mm long. Bamboo dowels shall not be used on slopes less than 30º to the horizontal.

(b) The chunam shall be laid to a total thickness of 50 mm in two equal layers; the layers

shall be well compacted by ramming. The bottom layer of chunam shall be left with a rough finish to provide bonding for the top layer.

(c) The top layer of chunam shall be thoroughly wetted and rubbed with sacks to fill any

cracks immediately before the chunam hardens. The surface shall be sprinkled with water and finished by trowelling to form a smooth uniform surface.

8.9.13 Joints in chunam

Joints in chunam shall be neat and straight and panels shall be rectangular. Joints in the top and bottom layers shall not coincide.

8.9.14 Weepholes in chunam

50 mm diameter PVC weepholes shall be constructed at 1.2 m staggered centres in each direction before chunam is placed; the weepholes shall penetrate at least 50 mm into the soil.

8.9.15 Temporary chunam surfaces

Temporary chunam surfaces to the faces of slopes or excavations shall consist of a single layer of chunam 20 mm thick, without bamboo dowels. Temporary chunam drainage channels shall be constructed by building up the chunam to an appropriate shape or by cutting a channel into the slope and lining with chunam. Temporary chunam shall be removed in stages before deposition of fill material or slope treatment works start.


8.9.16 Preparation of slope surfaces for sprayed concrete

(a) Weak material along joints or seams in slope surfaces to which sprayed concrete will be applied shall be removed to a depth equal to the width of the weak zone.

(b) When the soil surface temperature exceeds 25C or the moisture content is less than

10%, the surface to be sprayed shall be watered using sprays. Hoses without sprays shall not be used. Spraying of water onto the slope surface shall be carried out not more than 1 hour before spraying of concrete starts.

8.9.17 Fixing reinforcement

Fabric reinforcement for sprayed concrete shall be fixed securely to the slope by steel nails or rawl bolts and shall be laid without sharp bends or creases. The cover to the reinforcement shall be at least 20 mm and laps between adjacent sheets shall be at least 150 mm.

8.9.18 Weepholes in sprayed concrete

50 mm diameter weepholes shall be constructed at 1.2 m staggered centres in each direction; the weepholes shall extend to the full thickness of the sprayed concrete.

8.9.19 Equipment for spraying concrete

Equipment for spraying concrete shall be the dry mix delivery type with water added at the nozzle. The equipment shall be fitted with weighbatching facilities. The equipment shall be capable of projecting a mixture of cement, fine and coarse aggregate and water at high velocity on to the surface of the slope to produce a dense homogeneous cover.

8.9.20 Spraying concrete

(a) The surface temperature and moisture content of the soil shall be measured, and the results submitted to the Project Manager for review, immediately before sprayed concrete is applied.

(b) The aggregate and sand for sprayed concrete shall be kept dry before mixing. The

water shall be added at the nozzle at the instant of application. The air and water supply, the rate of application and all other factors affecting the quality of the work shall be adjusted to produce dense concrete with no sloughing. Rebound material shall not be reused and shall be removed within 8 hours after spraying.

(c) Sprayed concrete shall be applied in layers not exceeding 50 mm thick to the total

thickness stated in the Contract. The maximum panel dimension shall not exceed 15 m.

8.9.21 Curing sprayed concrete

Sprayed concrete shall be cured for at least 4 days after application by either Method 1, Method 2 or Method 3 as stated in Clause 20.7.15.

8.9.22 Fixing protective mesh for slopes

Protective mesh for slopes shall be suspended down the rock face and bolted into the slope face at 250 mm centres at the top and sides of the mesh and at 5 m intervals at the toe of the slope. Laps in the mesh shall be at least 300 mm and each side of the lap shall be tied at 125 mm centres with galvanised and PVC coated binding wire.


8.9.23 Trials for rock bolts

The design bond length of rock bolts with bonded anchorages shall be determined for each rock type by a pull-out trial. The proof load of a pull-out trial shall be twice the working load. Pull-out trials shall be carried out on two bolts for each combination of rock bolt and rock type. The bolts used in trials shall be discarded and shall not form part of the Permanent Works, and the hole shall be sealed by grouting.

8.9.24 Drilling, preparing and testing rock bolt holes

(a) Holes for rock bolts shall be drilled at the locations and to depths directed by the Project Manager. The diameter of the hole shall be at least 20 mm larger than the diameter of the rock bolt or the outer diameter of the connectors, whichever is larger. The method of drilling shall be rotary or rotary percussive with water flush or air flush accompanied by the operation of an effective dust extraction and filtering device. Holes shall be drilled to provide 50 mm cover to the end of bolts for which cement grout is used to form the bond length.

(b) Holes for rock bolt shall be flushed with clean water before rock bolt installation

starts until the return water runs clear. Standing water shall be blown out from the hole using compressed air after flushing.

(c) Holes for rock bolts shall be tested by the Packer test as stated in Clauses 8.10.11,

8.10.12 and 8.10.13 and the results of the tests shall be submitted to the Project Manager for review, before installation of rock bolts starts.

8.9.25 Fixing rock bolts

(a) The Project Manager shall be notified before installation of rock bolts starts. (b) Rock bolts shall be installed in accordance with the manufacturer's recommendations. (c) Rock bolts shall be fully grouted after stressing. (d) Installation of rock bolts, including grouting of the free length and installation of head

protection, shall be completed as soon as practicable and not more than 14 days after completion of the drillhole.

(e) Rock bolts with a grouted anchorage shall not be stressed until the grout crushing

strength has attained a value of 21 MPa when tested in accordance with Clauses 8.15.9, 8.15.10 and 8.15.11.

8.9.26 Grouting rock bolts

(a) Grouting for rock bolts shall be in accordance with the requirements stated in Clauses 8.11 to 8.15 except as stated in Clause 8.9.26(b) and (c).

(b) Grout shall be introduced at the lower end of drillholes with downward inclinations

and shall displace all air and water through the top of the drillhole. (c) Packers and return ducts which maintain a head on the grout until the grout has set

shall be used for drillholes with upward inclinations or with inadequate downward inclinations. The packers and ducts shall be such that separate grouting of the anchorage zone and free-length zone of the drillhole can be carried out. The head to be maintained on the grout shall be as reviewed without objection by the Project Manager.


8.9.27 Proving rock bolts Each installed rock bolt shall be proved as stated in Clauses 8.10.14 to 8.10.16 Rock bolts shall be locked off at 1.1 times the working load after proving. The complete bolt head assembly shall be encased by a concrete block after locking off.

8.9.28 Records of rock bolts

Records of installation of rock bolts shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 7 days after each installation operation. Records shall contain the following:

(a) rock bolt identification number;

(b) drilling details, including:

- date and time drilling started and finished; - machine and operator identification; - location, level, inclination, bearing, length and diameter of drillhole; and - rate of penetration at 0.5 m intervals;

(c) watertightness of drillhole, including:

- date and time water test started and finished; - details of any pre-grouting and redrilling; - length of test zone; - water pressure applied; - duration of test; and - measured water absorption rate;

(d) details of steel bolts, including:

- type and diameter; - bond length; - overall length; - number and type of centralising spacers; and - stressing record and lock-off load;

(e) details of grouting, including:

- date and time grouting started and finished; - details of any packers used and length of grouted zones; - head maintained on grout during setting; - volume of grout accepted; and - identification marks of grout cubes.

8.9.29 Drilling and preparation of rock dowel holes

The drilling and preparation of holes for rock dowels shall be as stated in Clause 8.9.24(a) and (b).

8.9.30 Grouting rock dowels

(a) Grouting for rock dowels shall be in accordance with the requirements stated in

Clauses 8.11 to 8.15 except as stated in Clause 8.9.30(b). (b) Rock dowels shall be grouted over the complete length of the drillhole in which the

dowel is installed. Centralisers shall be fitted to rock dowels before grouting to ensure an even annulus of grout.


8.9.31 Records of rock dowels

Records of installation of rock dowels shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 7 days after each installation operation. The records shall contain at least the following details:-

(a) rock dowel identification number;

(b) drilling details, including:

- date and time drilling started and finished; - machine and operator identification; - location, level, inclination, bearing, length and diameter of drillhole; and - rate of penetration at 0.5m intervals;

(c) watertightness of drillhole, including:

- date and time water test started and finished; - details of any pre-grouting and redrilling; - length of test zone; - water pressure applied; - duration of test; and - measured water absorption rate;

(d) details of steel dowels, including:

- type and diameter; - bond length; - overall length; and - number and type of centralising spacers; and

(e) details of grouting, including:

- date and time grouting started and finished; - details of any packers used and length of grouted zones; - head maintained on grout during setting; - volume of grout accepted; - identification marks of grout cubes; and - results of cube tests on grout.

8.10 INSPECTION, TESTING AND COMMISSIONING – SLOPE TREATMENT

WORKS 8.10.1 Chunam Surface Trial panel

A trial panel 50 mm thick and at least 3m x 3m shall be constructed for chunam surfaces.

8.10.2 Trial panel

A trial panel at least 50 mm thick and at least 3m x 3m shall be constructed for sprayed concrete on the surface to be treated. The average percentage rebound shall be estimated for each trial panel and shall be used in the calculations of the cement content of the applied concrete.


8.10.3 Inspection of sprayed concrete

Completed areas of sprayed concrete shall be sounded using a wooden mallet; areas which in the opinion of the Project Manager are substandard or hollow shall be removed and resprayed.

8.10.4 Records of sprayed concrete

Records of sprayed concrete operations shall be kept by the Contractor on Site and shall be submitted daily to the Project Manager for review. The records shall contain details of the quantities of all materials used at each location.

8.10.5 Testing: Optimum moisture content and maximum dry density of soil-cement fill

The maximum dry density and optimum moisture content of soil-cement fill shall be tested as stated in Clauses 7.5.7 to 7.5.13 except that the method of testing shall be the Vibrating Hammer Test Method in accordance with BS 1924.

8.10.6 Testing: test panels for sprayed concrete

(a) The strength of sprayed concrete shall be determined from concrete cores cut from a test panel constructed at the same time as sprayed concrete is applied.

(b) One test panel shall be constructed for each area of sprayed concrete of 500 m² or part thereof.

(c) The test panel shall be 250 mm thick and shall be at least 1 m x 1 m. The mould shall

be securely fixed in position at the same height and inclination as the surface being sprayed. The panel shall be constructed by spraying concrete into the mould at the same time as the concrete to be tested is applied. The test panel shall be cured by the same method as the sprayed concrete.

8.10.7 Samples: concrete cores from sprayed concrete

(a) Three concrete cores shall be provided from each test panel; cores shall not be taken within 125 mm from the edges of the panel.

(b) Concrete cores shall be 100 mm diameter and shall be the full depth of the test panel. (c) The method of taking concrete cores shall be in accordance with CS 1.

8.10.8 Testing: concrete cores from sprayed concrete (a) Each concrete core shall be tested to determine the compressive strength and density. (b) The method of preparing and testing the cores to determine the compressive strength

shall be in accordance with CS 1; the method of testing the cores to determine the density shall be in accordance with CS 1. Three concrete cores shall be tested at 28 days.

8.10.9 Compliance criteria: concrete cores from sprayed concrete

The results of tests for compressive strength of concrete cores shall be interpreted in accordance with BS 6089. Adjustments to the measured strength in respect of the age of the core when tested shall not be made. The minimum compressive strength of concrete cores, converted to estimated in-situ cube strength in accordance with BS 6089 shall be 20 MPa at 28 days.


8.10.10 Non-compliance: concrete cores from sprayed concrete

If the result of any test for compressive strength or density of concrete cores from sprayed concrete does not comply with the specified requirements for the property, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review; further trial mixes shall be made and further trial panels shall be constructed.

8.10.11 Testing: Packer test

(a) The water loss from drillholes for rock bolts shall be determined by the Packer test. The number of drillholes to be tested will be directed by the Project Manager.

(b) The Packer test shall be carried out on the bond length of the drillhole at a test

pressure of 100 kPa. The method of testing shall be as stated in Clause 8.15.12.

8.10.12 Compliance criteria: Packer test

The water loss determined by the Packer test in the grouted hole shall not exceed 5 Lugeons when measured over a 10 minute period.

8.10.13 Non-compliance: Packer test

If the result of any Packer test on drillholes for rock bolts does not comply with the specified requirements for the test, the drillhole shall be grouted, re-drilled and retested. Grouting, re-drilling and retesting shall be continued until the result of the Packer test complies with the specified requirements for the test.

8.10.14 Testing: rock bolts

Each installed rock bolt shall be tested to determine the loss in stress by applying a test load of 1.5 times the working load for 5 minutes.

8.10.15 Compliance criteria: rock bolts

The loss in stress in installed rock bolts shall not exceed 5% of the test load in 5 minutes. 8.10.16 Non-compliance: rock bolts

(a) If the result of any test for loss in stress of installed rock bolts does not comply with the specified requirements for the test, an additional test for loss of stress shall be carried out on the rock bolt.

(b) If the result of any additional test for loss of stress of installed rock bolts does not

comply with the specified requirements for the test, the rock bolt shall be replaced.


8.11 DEFINITIONS AND ABBREVIATIONS - GROUTING FOR GEOTECHNICAL WORKS

8.11.1 Ground

Ground, for the purpose of grouting for geotechnical works, is fill material, soil and rock and the interfaces between fill material, soil and rock and any structures.

8.11.2 Grout

Grout, for the purpose of grouting for geotechnical works, is cement grout, cement-sand grout, cement-bentonite grout and proprietary grout reviewed without objection by the Project Manager.

8.11.3 Grouting

Grouting, for the purpose of grouting for geotechnical works, is the mixing and injection of grout through predrilled or preformed holes.

8.11.4 Grouting stage

Grouting stage, for the purpose of grouting for geotechnical works, is the discrete length of drillhole into which grout is to be injected in a continuous operation.

8.11.5 Lugeon

Lugeon is a water loss of 1 litre per minute per metre length of hole tested at an effective pressure of 1 MPa.

8.11.6 Batch: grout for geotechnical works

A batch of grout for geotechnical works is any quantity of grout used for grouting geotechnical works in one continuous operation in one day.

8.12 MATERIALS – GROUTING FOR GEOTECHNICAL WORKS 8.12.1 Materials for grout Materials for grout shall comply with Section 20 except as stated in this Section. 8.12.2 Grout for geotechnical works

(a) Cement grout for geotechnical works shall consist of OPC, sand and water. Admixtures shall not be used.

(b) Sand for grout shall be clean dry sand complying with BS 1200 and shall have a

particle size distribution such that 100% passes a 2 mm BS test sieve and not more than 30% passes a 0.2 mm BS test sieve.

(c) Water for grout shall be clean fresh water having a temperature not exceeding 30C or

less than 5C. (d) Unless otherwise stated in the Contract, cement grout shall have a minimum crushing

strength of 30 MPa at 28 days.


(e) The amount of bleeding of grout shall not exceed 0.5% by volume 3 hours after mixing or 1.0% maximum when measured at 23 ±2C in a covered glass or metal cylinder of 100 mm internal diameter and with a grout depth of approximately 100mm. In addition, the water shall be reabsorbed by the grout within 24 hours.

(f) The flow cone efflux time of grout shall not be less than 15 seconds.

8.12.3 Standpipes

Standpipes for grouting shall be standard black metal pipe complying with BS 1387. 8.13 SUBMISSION – GROUTING FOR GEOTECHNICAL WORKS 8.13.1 Particulars of grouting for geotechnical works

(a) The following particulars of the proposed materials and methods of construction for grouting for geotechnical works shall be submitted to the Project Manager for review:

(i) details of drilling, grouting and testing equipment;

(ii) details of grout mix, including admixtures;

(iii) methods of storing, mixing and injecting grout;

(iv) methods of drilling, cleaning, capping and sealing grout holes;

(v) methods of grouting, including grouting stages, order of working and

regrouting methods; and

(vi) methods of controlling surface water, groundwater, leakage and ground movement, including methods of monitoring and instrumentation.

8.14 WORKMANSHIP – GROUTING FOR GEOTECHNICAL WORKS 8.14.1 Drilling for grouting for geotechnical works

(a) Holes in rock for grouting for geotechnical works shall be drilled using rotary or percussion type drills. The tolerance for the holes shall be as stated in Clause 8.5.8(a). Grease and other lubricants shall not be used in the flushing medium or on the rods, except around the threads at the ends of the rods. Drilling methods which result in drill cuttings causing blockages such that grouting cannot be performed satisfactorily shall not be used.

(b) The flushing medium for drilling shall be air, air mist, clean water or air accompanied

by the operation of an effective dust extraction and filtering device. (c) The minimum size of hole for grouting in rock shall be 40 mm. (d) Holes in soil for grouting for geotechnical works shall be drilled by a method which is

suitable to the ground conditions and which is reviewed without objection by the Project Manager.


(e) The location of all underground obstructions and utilities shall be determined by the Contractor before drilling starts and the drilling pattern shall take account of the location of obstructions and utilities.

(f) Casings required to prevent the collapse of grout holes shall be as stated in Clause

8.5.7. Casings shall be removed immediately before or simultaneously with the grouting or sleeve grouting operation in such a manner that the grout hole will not collapse and the injection of grout will not be hindered.

(g) Grout holes shall be flushed clean with water or compressed air introduced at the

bottom of the hole after drilling is complete. The holes shall be protected with capping pipes or standpipes to prevent subsequent collapse or clogging after flushing.

(h) Grout holes which have been drilled more than one day before grouting of the hole

starts shall be reflushed with water or compressed air immediately before grouting is commenced and excess flushing water shall be removed by air jet. Holes drilled in soft ground or in ground other than rock and in which sleeve grouts are proposed as part of the grouting operation shall be sleeve grouted as soon as practicable after drilling.

8.14.2 Standpipes and capping pipes

(a) Grout holes shall be capped after drilling and before grouting. Capping shall be by a suitably sealed grout connection, standpipe or packer. The cap shall seal the hole to prevent contamination or clogging of the hole until grouting operations start.

(b) Standpipes, if stated in the Contract, shall be installed in holes after drilling. The pipe

shall be sealed into the hole using cement grout consisting of OPC and water in the proportions 1:1 by volume.

8.14.3 Monitoring of grouting operations

(a) Instrumentation shall be installed to monitor heave, bulging, settlement, lateral movement, deformation or fracturing of the ground or structures due to grouting operations. Records of monitoring shall be kept by the Contractor on Site and a copy submitted to the Project Manager for review. Arrangements for installing instruments and taking measurements inside and outside the Site shall be made by the Contractor.

(b) The accuracy of the instruments shall be checked before grouting starts and at regular

intervals reviewed without objection by the Project Manager. 8.14.4 Grouting equipment

(a) Standby grouting equipment shall be available at all times and shall be capable of being brought into operation immediately in the event of breakdowns during grouting operations.

(b) Grout mixers shall be high speed colloidal mixers having a rotor speed of at least

1000 rpm and capable of producing a colloidal grout mix. Mixers shall be fitted with a water volume measuring device for batching purposes.

(c) Holding tanks shall be fitted with an agitator to provide continuous agitation of the

grout at 100 rpm. The tank shall be fitted with a dipstick to allow continuous measurement of the volume of grout in the tank. A 2.36 mm removable screen shall be provided between the tank and the pump or grout lines.


(d) Grout pumps shall be a positive displacement type. Pumps shall be fitted with bypass valves to allow a standby pump to be brought into operation.

(e) Working pressure gauges shall be accurate to within 3% and shall be calibrated

against a test gauge before grouting starts and at weekly intervals. A test gauge with accompanying calibration certificates shall be kept on Site for the purpose of calibrating working gauges. Working gauges shall be numbered and a record shall be kept of gauge number, shifts worked, calibration dates and repairs undertaken; records shall be kept on Site and shall be available for inspection by the Project Manager at all times.

(f) Packers shall be such that they seal holes in rock at the specified level and shall be

capable of withstanding the maximum grout or water pressure to be used at that level without leakage. Packers shall be of the mechanical or inflatable rubber type. A sufficient number of packers of a size to suit the holes shall be available on Site.

(g) Grout hoses shall be of sufficient length and shall be arranged in such a manner to

allow continuous circulation of the grout from the pump to the hole and back to the agitator and holding tank. Circulation hose lengths shall be kept to a minimum and sufficient spare hose shall be available in the event of ruptures.

8.14.5 Mixing grout

(a) Grout for geotechnical works shall be batched by weight. The mix proportions may be adjusted if permitted by the Project Manager depending on the results of the trial grouting, water tests in the hole or the results of previously grouted holes.

(b) Grout shall be mixed by adding approximately two-thirds of the cement to the water

adding any admixture and adding the remaining one-third of cement. Other mixing procedures shall not be used.

(c) The time for which grout shall be mixed in high speed mixers shall be suitable for the

type of mixer used. Grout shall be continuously agitated in a holding tank after mixing and shall be screened before being circulated in the grout lines. Mixed grout shall be continuously circulated in such a manner that grout which is not taken in a hole can be returned to the holding tank.

(d) Grout to which a retarding agent has not been added, and which is not used within 2

hours after mixing, shall not be used for grouting. 8.14.6 Pressure grouting

(a) Holes in rock shall be grouted in grouting stages not exceeding 3 m. Grouting shall be carried out in either an upstage or a downstage sequence.

(b) Ground other than rock shall be grouted in such a manner that grout can be injected at

various points along the grout hole in a multi-stage operation. The grouting method shall employ perforated pipes with rubber sleeve valves.

(c) Grouting pressures shall initially be 100 kPa per 4 metre depth of hole and shall not

exceed the overburden pressure. (d) Holes shall be grouted in a continuous operation at the grouting stages and pressures

stated in the Contract. Grouting shall be carried out by injecting the grout under pressure into each grouting stage of the hole until the grouting stage refuses to take further grout.


(e) If grouting of any hole or grouting stage has not been completed due to excessive grout takes, low pressures, excessive leakage or other causes, the hole shall be redrilled or flushed out with water and re-injected with grout.

8.14.7 Loss or leakage of grout

(a) If during the grouting of any hole, grout is found to flow from adjacent grout holes in quantities which interfere with the grouting operation or to cause appreciable loss of grout, the holes shall be temporarily capped. If capping is not essential, ungrouted holes shall be left open to allow air and water to escape.

(b) If during the grouting of any hole grout is found to flow from joints in the geological

formation at the Site or any other location, the leaks shall be plugged or caulked in a manner reviewed without objection by the Project Manager.

(c) If during the grouting of any hole the grout take increases suddenly by a significant

amount, the Project Manager shall be notified immediately. 8.14.8 Making good holes

(a) Grout holes through concrete shall be made good using concrete reviewed without objection by the Project Manager. The concrete shall be firmly compacted and shall be finished to match the adjacent surface.

(b) Uncapped holes in rock shall be topped up after grouting using cement grout

consisting of OPC and water in the proportions 1:1 by volume, or 1:3 cement sand mortar.

8.15 INSPECTION, TESTING AND COMMISSIONING – GROUTING FOR

GEOTECHNICAL WORKS 8.15.1 Trials for grouting

A grouting trial shall be carried out. The extent and depth of holes for grouting trials and the tests to be carried out shall be as stated in the Contract or as directed by the Project Manager.

8.15.2 Records of grouting for geotechnical works

(a) Records of grouting for geotechnical works shall be kept by the Contractor on Site and shall be available for inspection by the Project Manager at all times. Records shall include the following details:

(i) hole location and reference number;

(ii) depth of hole;

(iii) type of grout and grout mix proportions;

(iv) volume of grout injected;

(v) grouting pressures; and

(vi) times and details of any interruptions, leakages and equipment malfunctions.


(b) A record of grouting for each hole shall be submitted to the Project Manager for review within 24 hours after completion of grouting of the hole. The record shall contain the following details:

(i) hole location and reference number; (ii) grouting stage numbers and lengths;

(iii) collar level and hole inclination;

(iv) details of grout injections including the information stated in Clause 8.25.7(a);

and

(v) details of the grouting procedure, including any stoppages, leaks to other holes, surface leaks and ground movement.

(c) A record of the testing for each hole, including test results, shall be submitted to the

Project Manager for review within 24 hours after completion of testing of a hole. Records of Packer tests shall contain the following details:

(i) hole location and reference number;

(ii) depth of packer in the hole;

(iii) date and time of test;

(iv) type of gauge or meter and identifying reference number;

(v) test readings for each 5 minute period;

(vi) calculated test results in Lugeons; and

(vii) details of any equipment malfunctions, sudden water losses or blockages,

surface leakage or other variations in test procedure.

(d) A report of grouting for each part of the Works as stated in the Contract, including record drawings and logs of holes, shall be submitted to the Project Manager for review within one week after completion and testing of grouting for that part of the Works. The form of records, logs and record drawings shall be submitted to the Project Manager for review.

8.15.3 Samples: bleeding of grout

(a) One sample of grout shall be provided from each batch of grout for geotechnical works to determine the amount of bleeding of the grout.

(b) Samples shall be provided not more than 30 minutes after the grout has been mixed

and shall be protected from moisture content changes before the tests for amount of bleeding are carried out.


8.15.4 Testing: bleeding of grout (a) Each sample of grout taken as stated in Clause 8.15.3 shall be divided into three

specimens; each specimen shall be tested to determine the amount of bleeding. (b) Grout for geotechnical works shall be tested for bleeding in accordance with Clause

21.6.24. 8.15.5 Non-compliance: bleeding of grout

If the result of any test for amount of bleeding of grout for geotechnical works does not comply with the specified requirements for amount of bleeding, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager for review; further grouting trials shall be carried out.

8.15.6 Samples: flow cone efflux time of grout

One sample of grout shall be provided from each batch of grout for geotechnical works to determine the flow cone efflux time of the grout.

8.15.7 Testing: flow cone efflux time of grout

Each sample of grout taken as stated in Clause 8.15.6 shall be tested to determine the flow cone efflux time. The method of testing shall be in accordance with Appendix A8.2.

8.15.8 Non-compliance: flow cone efflux time of grout

If the result of any test for flow cone efflux time of grout does not comply with the specified requirements for flow cone efflux time, particulars of proposed changes to the materials, grout mix or methods of production shall be submitted to the Project Manager; further grouting trials shall be carried out.

8.15.9 Samples: crushing strength of grout

(a) One sample of grout shall be provided from each batch of grout for geotechnical works to determine the crushing strength of the grout.

(b) Samples shall be provided not more than one hour after the grout has been mixed and

shall be protected from moisture content changes before test cubes are made.

8.15.10 Testing: crushing strength of grout (a) Nine 100 mm test cubes shall be made from each sample of grout taken as stated in

Clause 8.15.9. Three test cubes shall be tested to determine the crushing strength at 3 days, three test cubes shall be tested to determine the crushing strength at 7 days and three test cubes shall be tested to determine the crushing strength at 28 days.

(b) The method of making, curing and testing the test cubes shall be as stated in Clause

20.8.12(b), (c) and (d).


8.15.11 Non-compliance : crushing strength of grout

If the result of any test for crushing strength of grout for geotechnical works does not comply with the specified requirements for grout, particulars of proposed changes to the materials, grout mix or method of production shall be submitted to the Project Manager for review. Further trial mixes shall be made and further grouting trials shall be carried out.

8.15.12 Testing: Packer tests

(a) The water loss from drillholes for grouting and from grouted and regrouted drillholes shall be determined by the Packer test.

(b) The number of drillholes for grouting to be tested to determine the water loss shall be

proposed by the Contractor and reviewed without objection by the Project Manager. (c) Every grouted drillhole and every regrouted drillhole shall be tested to determine the

water loss. (d) Packer tests shall be carried out in accordance with BS 5930, Chapter 21.5, and

Clauses 8.15.12(e) to (h). (e) Tests shall be carried out using clean water, in grouting stages not exceeding 3 m in

length. The rate of flow of water in the test shall be determined to an accuracy of 10% for flows exceeding 1 L/min.

(f) The test pressure shall be equal to the overburden pressure and shall not exceed the

specified maximum grouting pressure for the grouting stage being tested. (g) The test shall be carried out between a packer and the base of the hole for grouting

stages at the base of a hole and shall be carried out between two packers in other cases.

(h) The test shall be carried out by pumping water at the specified pressure into the

grouting stage being tested and measuring with a volume meter the water loss over three consecutive 10 minute periods. The result shall be calculated in Lugeons for each 10 minute period.

8.15.13 Compliance criteria: Packer tests

The water loss determined by the Packer test in the grouted hole shall not exceed 5 Lugeons when measured over a 10 minute period.

8.15.14 Non-compliance: Packer test on drillholes for grouting

If the result of any Packer test on drillholes for grouting does not comply with the specified requirements for the test, the drillhole shall be grouted, re-drilled and retested. Grouting, re-drilling and retesting shall continue until the result of the Packer test complies with the specified requirements for the test.

8.15.15 Non-compliance: Packer test on grouted and regrouted drillholes

If the result of any Packer test on grouted drillholes or regrouted drillholes does not comply with the specified requirements for the test, the grout shall be removed and the drillhole shall be regrouted and retested. Removal of grout, regrouting and retesting shall continue until the result of the Packer test complies with the specified requirements for the test.


8.16 DEFINITIONS AND ABBREVIATIONS - GROUNDWATER DRAINAGE AND CONTROL

8.16.1 Caisson drain

Caisson drain is an excavated vertical shaft, with or without raking drains, to provide drainage by intercepting and lowering the groundwater level in the vicinity.

8.16.2 Geotextile filter

Geotextile filter is a permeable sheet of synthetic material used like a granular filter for filtration and in-plane drainage.

8.16.3 Filter pipe

Filter pipe is a perforated or non-perforated pipe used for draining groundwater. 8.16.4 Granular filter

Granular filter is a graded sand or gravel placed against soil to prevent the migration of fine particles out of the soil caused by water flow, and graded such that free discharge of water flowing into the filter is allowed.

8.16.5 Prefabricated band drain

Prefabricated band drain is a synthetic drain which, when installed in a soil strata, acts as a drainage medium for dissipation of pore water pressure.

8.16.6 Raking drain

Raking drain is a drillhole, with or without perforated filter pipes and geotextile filter sheath, installed generally at an upward inclination for groundwater lowering by gravity flow.

8.16.7 Relief drain

Relief drain is a synthetic drain installed on slope surfaces or in excavations to divert water seepage before applying sprayed concrete, chunam, masonry dentition or other construction.

8.16.8 Trench drain

Trench drain is a trench wholly or partly filled with granular material or clean crushed rock, with or without filter pipes and geotextile filter.

8.17 MATERIALS – GROUNDWATER DRAINAGE AND CONTROL 8.17.1 Granular filter material

Granular filter material for granular filter, trench drains and caisson drains shall consist of durable, inert, natural material free from clay, organic material and other impurities. Granular filter material shall have the particle size distribution stated in the Contract.


8.17.2 Geotextile filter

Geotextile filter shall be a proprietary type reviewed without objection by the Project Manager and unless otherwise stated in the Contract shall have the following properties :

- Trapezoidal tear resistance (ASTM D4533-85) : 0.225kN; - CBR puncture resistance (DIN 54307) : 1.0kN;

- Piping limit : non-cohesive soil : 090 D85 Soil; and

: cohesive soil : 090 0.12mm; and

- Permeability limit : 090 D15 Soil; and

: 090 0.05mm.

where :-

090 is the pore size below which lies 90% of the pore sizes in the geotextile;

D85, D15 is the particle sizes below which lie 85% and 15% by weight of the soil to be

filtered (only fraction smaller than 5mm to be considered) 8.17.3 Filter pipes

(a) Filter pipes shall comply with the following: Precast concrete pipes : BS 5911 Vitrified clay pipes : BS 65 DI pipes : BS 4772 Steel pipes : BS 534 Porous concrete pipes : BS 1194 Perforated concrete pipes : BS 5911 Pitch fibre pipes : BS 2760 UPVC pipes : BS 4660 or BS 3506 Corrugated polyethylene tubing : AASHTO Designation M252

(b) Class O UPVC pipes shall not be used. (c) The perforations in perforated pipes shall be cleanly cut and shall be uniformly spaced

along the length and circumference of the pipe. (d) UPVC plastic pipes shall be jointed by couplers.


8.17.4 Raking drains

(a) Type O raking drains shall be unlined raking drains; drain holes shall be at least 40 mm diameter.

(b) Type 1 raking drains shall be single pipe raking drains consisting of a single

perforated pipe with a non-perforated invert. (c) Type 2 raking drains shall be single pipe raking drains consisting of a single

perforated pipe with a non-perforated invert and enclosed within a geotextile filter sheath.

(d) Type 3 raking drains shall be double pipe raking drains consisting of an outer

permanent pipe and an inner removable pipe enclosed within a geotextile filter sheath; the outer and inner pipes shall be perforated pipes with a non-perforated invert.

(e) Pipes for raking drains shall be as stated in Clause 8.17.3 (a) and (b); the openings

and slots in pipes with non-perforated inverts shall cover approximately two-thirds of the circumference of the pipe.

(f) Geotextile filter sheaths for raking drains shall be formed of woven or non-woven geotextile filter complying with Clause 8.17.2.

8.17.5 Fill material for trench drains

(a) Fill material to be used with geotextile filter in trench drains shall be clean crushed rock. Type A and Type B fill material shall have the particle size distributions stated in Table 8.2.

(b) Fill material passing a 425 m BS test sieve shall be non-plastic. (c) The D15 particle size of Type A fill material for use with perforated pipes shall be at

least 15% larger than twice the maximum dimension of the perforations, where D15 is the equivalent sieve size in millimetres, interpolated from the particle size distribution curve, through which 15% of the fill material would pass.

(d) The Contractor shall check if the fill material to be used as a filter medium is in the

following relationship with the base soil, including any necessary soil testing:-

(i) D15Fc shall be less than 5 x D85Sf.

(ii) D15Ff shall be greater than 5 x D15Sc.

(iii) Uniformity Coefficient )F10D

F60D( shall be greater than 4 and less than 20.

(iv) Material shall not be gap graded.

(v) All material shall be less than 50 mm in size.

(vi) Not more than 5% of the material shall pass the 63 micron sieve and that

fraction shall be cohesionless.


(vii) Within 48 hours of completion of the checking and testing, the Contractor shall submit to the Project Manager the results of these checks and tests.

Legend (I) D15F is used to designate the fifteen percent size of the filter material,

that is, the size of the sieve that allows fifteen percent by weight of the filter material to pass through. Similarly, D85S designates the size of sieve that allows eighty-five percent by weight of the base soil to pass through. The subscript ‘c’ denotes the coarse side of the envelope; the subscript `f' denotes the fine side.

(II) If the filter grading Type A or B in Table 8.2 does not satisfy Clause

8.17.5(d), the Contractor shall design the filter material so as to comply with this Clause. The Contractor shall submit the relevant details to the Project Manager at least four weeks in advance of the commencement of laying of filter material on Site.

(III) The Contractor shall also design the filter so as to prevent filter material

being washed into the pipe as defined in Clause 8.17.5(c). (e) Filter material shall be placed and compacted in such a manner as to avoid segregation

of the various grain sizes. Table 8.2: Particle Size Distribution of Fill Material for Trench Drains

Percentage by mass passing BS test sieve Type of fill

material 63 mm

37.5 mm 20 mm 10 mm 3.35 mm 600 m 63 m

Type A - 100 - 45-100 25-80 8-25 0 – 5

Type B 100 85-100 0-20 0-5 - - -

8.17.6 Caisson liners

Caisson liners shall be concrete tapered rings at least 100 mm thick and not exceeding 1 m deep. The liners shall be constructed with well-compacted concrete of Grade 20/20 or greater.

8.17.7 Prefabricated band drains

(a) Prefabricated band drains shall consist of a core and a filter. The drains may be manufactured as a single unit or the filter may be wrapped around the core, and overlapped and sealed to contain the core. The drains shall be made from chemically treated paper, polyethylene, polyester, polyolefine or other synthetic material or combination of such materials.

(b) Prefabricated band drains shall be provided with an outer casing or mandrel of

rhomboidal or rectangular cross section for use during installation. The drains shall also be provided with an anchor to ensure embedment of the drain during extraction of the mandrel.

(c) The strength of the materials in prefabricated band drains shall be such that the drains

will withstand all forces resulting from handling and installation.


(d) The filter jacket for prefabricated band drains shall be a type which:

(i) has been previously proved effective under similar soil and pressure conditions,

(ii) is in all cases able to prevent excessive migration of soil particles into the core, and

(iii) has a permeability not less than that of the surrounding soil.

(e) Prefabricated band drains shall be able to conform to soil deformation without

buckling or crimping of the core. (f) Prior to the installation of the drains within the designated areas, the Contractor shall

demonstrate that his equipment, method and materials produce a satisfactory installation in accordance with the Specification. The Contractor shall install trial drains at locations designated by the Project Manager.

(g) The end of each drain shall be provided with a suitable disposable shoe of an

acceptable type to ensure that the drain is securely anchored at its base level.

8.18 SUBMISSIONS – GROUNDWATER DRAINAGE AND CONTROL 8.18.1 Particulars of granular filters

(a) The following particulars of the proposed materials and methods of construction for granular filters shall be submitted to the Project Manager for review: (i) whether granular filter material is to be supplied ready mixed or is to be mixed

on the Site;

(ii) source of supply, including name of supplier of ready mixed material;

(iii) quantity of each constituent if the material is to be mixed on Site;

(iv) Contractor's Equipment and methods of mixing for material mixed on Site;

(v) method of storage and location of storage areas on Site;

(vi) methods of deposition and compaction of material; and

(vii) results of three tests for particle size distribution of the fill material against which the granular filter is to be placed.

8.18.2 Particulars of geotextile filter

(a) The following particulars of the proposed materials and methods of construction for geotextile filter shall be submitted to the Project Manager for review:

(i) manufacturer's name and source of supply;

(ii) details of geotextile filter including manufacturer's literature;


(iii) a certificate for the geotextile filter showing the manufacturer's name, the date and place of manufacture and showing that the geotextile filter complies with the requirements stated in the Contract, and including results of the following tests :

- particle size distribution of sub-grade (BS 1377 : 1975 : Part 3); and - determination of pH of sub-grade and sub-ballast (BS 1377 : 1975 : Part 2);

(iv) calculations showing that the geotextile filter complies with the filtration

characteristics stated in the Contract;

(v) details of previous uses of the geotextile filter;

(vi) details of quantities to be supplied in each delivery;

(vii) method of storage;

(viii) methods of cutting and jointing geotextile filter;

(ix) method of repairing small batches; and

(x) methods of laying and holding in position. 8.18.3 Particulars of trench drains

(a) The following particulars of the proposed materials and methods of construction for trench drains shall be submitted to the Project Manager for review: (i) method of excavation of trench and installation of geotextile filter;

(ii) details of granular fill material as stated in Clause 8.17.5; and

(iii) details of geotextile filter as stated in Clause 8.18.2.

8.18.4 Particulars of raking drains

(a) The following particulars of the proposed materials and methods of construction for raking drains shall be submitted to the Project Manager for review:

(i) method of connecting adjacent sections of pipes;

(ii) proportions of sealant mix; and

(iii) details of geotextile filter sheath.

8.18.5 Particulars of relief drains

(a) The following particulars of the proposed materials and methods of construction for relief drains shall be submitted to the Project Manager for review:

(i) details of relief drains and outlets; and

(ii) method of fixing relief drains to the slope face.


8.18.6 Particulars of caisson drains

(a) The following particulars of the proposed materials and methods of construction for caisson drains shall be submitted to the Project Manager for review:

(i) methods of excavation and installation and removal of caisson liners;

(ii) method of compaction of fill material;

(iii) details of granular filter material as stated in Clause 8.18.1; and

(iv) details of geotextile filter as stated in Clause 8.18.2.

8.18.7 Particulars of prefabricated band drains

(a) The following particulars of the proposed materials and methods of construction for prefabricated band drains shall be submitted to the Project Manager for review: (i) details of type of drain, including manufacturer's literature;

(ii) a certificate showing the manufacturer's name, the date and place of

manufacture and showing that the drains comply with the requirements stated in the Contract;

(iii) details of previous installations by the Contractor using similar drains;

(iv) method of installation; and

(v) details of installation mandrel, drain anchor, method of penetration and method

of recording depth of installation.

(b) Subject to a satisfactory installation of trial drains the Contractor shall submit to the Project Manager for review the following particulars of his proposal:-

(i) a detailed layout of drains with reference numbers, which shall comply with the

spacing requirements shown on the Employer’s Drawings. In his proposed layout, the Contractor shall take into account all foreseeable obstructions to the installation of drains (e.g. transition pile caps, retaining wall etc) and shall include proposals to revise the area limits of drains as necessary to avoid such obstructions;

(ii) the base level of each vertical drain which shall comply with the requirements

shown on Employer’s Drawings; and

(iii) the supporting calculations and ground investigation logs on which his proposal is based.

(c) The Contractor shall carry out confirmatory drilling before the installation of

pneumatic piezometer tips and drains.

8.18.8 Particulars of filter pipes

(a) The following particulars of the proposed materials and methods of construction for filter pipes shall be submitted to the Project Manager for review: (i) details of type of pipes, including manufacturer's literature;


(ii) a certificate showing the manufacturer's name, the date and place of manufacture and showing that the pipes comply with the requirements stated in the Contract;

(iii) details of previous installations by the Contractor using similar pipes; and

(iv) method of installation.

8.18.9 Particulars of groundwater control, drawdown and monitoring

(a) The following particulars of the proposed materials and methods of construction for groundwater control, drawdown and monitoring shall be submitted to the Project Manager for review :- (i) Contractor's Equipment and materials for dewatering; (ii) timing and sequence of dewatering operations;

(iii) details of silt traps;

(iv) methods of monitoring flow rates and volumes of silt, including monitoring

intervals; and

(v) methods and locations for discharging groundwater. 8.18.10 Representative samples of materials

Representative samples of the following proposed materials shall be submitted to the Project Manager for review at the same time as particulars of the material (Clause 8.18.9) are submitted:

(a) granular filter material; (b) geotextile filter and two pieces of geotextile filter joined in accordance with the

manufacturer's recommendations for each type of joint; and (c) relief drains.

8.18.11 Handling and storage of granular filter material

(a) Granular filter material shall not be handled or stored in a manner which will result in mixing of the different types and sizes or in segregation, contamination, deterioration or erosion of the material.

(b) Stockpiles of granular filter material shall be placed on well-drained, prepared areas

and shall be separated by dividing walls of sufficient height to keep the different materials separate.

8.18.12 Delivery and storage of geotextile filter

(a) Geotextile filter shall be delivered in secure wrappings to ensure that the geotextile filter is dry and protected from damage, contamination and exposure to conditions which may adversely affect it.


(b) Geotextile filter shall be stored on a level surface and shall be kept in a secure and dry condition, which will not result in damage to the fabric or in contamination of the fabric.

(c) Geotextile filter which is damaged shall not be used in the Permanent Works.

8.18.13 Storage of filter pipes

Coils of plastic tubing for filter pipes shall be stored flat.

8.18.14 Delivery and storage of prefabricated band drains

(a) Prefabricated band drains shall be supplied in rolls, securely packed in light-proof wrappings.

(b) Prefabricated band drains shall be stored in a clean, dry environment.

8.19 WORKMANSHIP – GROUNDWATER DRAINAGE AND CONTROL 8.19.1 Mixing granular filter material

Granular filter material shall be thoroughly mixed by the method reviewed without objection by the Project Manager. Material which has been stockpiled shall be remixed before deposition.

8.19.2 Deposition and compaction of granular filter material

(a) Granular filter material shall be deposited and compacted as stated in Clauses 7.4.20

to 7.4.29. (b) Granular filter material shall be deposited in a manner which will not result in

segregation or contamination of the material. (c) Granular filter material shall be deposited in such a manner that a continuous free

draining zone is formed. The surface of each layer shall be cleaned and scarified before the next layer is deposited.

8.19.3 Damage to geotextile filter

(a) The total period for which geotextile filter is exposed to daylight or other sources of ultra-violet radiation during handling, delivery, storage and installation shall not exceed 7 days.

(b) Geotextile filter which has been damaged or exposed to daylight or other sources of

ultra-violet radiation for longer than the period stated in Clause 8.19.3(a) shall not be used in the Permanent Works.

(c) Repairs to geotextile filter which has been torn or damaged during installation shall be

carried out using a patch of the same material extending at least 300 mm beyond the edge of the damaged area. Repairs shall not be carried out on geotextile filter which has been damaged during storage or storage before installation.


8.19.4 Laying geotextile filter

(a) Geotextile filter shall be installed in such a manner that the individual yarns, webs or layers of the fabric retain their intended orientation and relative positions with respect to each another.

(b) Geotextile filter shall be installed, cut and jointed in accordance with the

manufacturer's recommendations. (c) Fabric reinforcement stated in the Contract not to be jointed shall be lapped by at least

300 mm. 8.19.5 Protection of geotextile filter

Contractor's Equipment and other vehicles shall not operate on installed geotextile filter unless it is adequately protected by a cover of fill material.

8.19.6 Installation of raking drains

(a) The length of raking drains assembled before installation shall not exceed 12.5 m. Connections between adjacent pipes shall be secured in such a manner that the cumulative longitudinal extension of a 12.5 m assembled length of pipe does not exceed 5 mm when pulled by hand.

(b) Pipes for Type 2 and Type 3 raking drains which are to be wrapped in a geotextile

filter sheath shall be placed along the centre of a strip of geotextile filter of sufficient width to allow a lap of at least 50 mm. The strip of geotextile filter shall be drawn around the pipe and fixed to the pipe along the pipe invert with non-metallic ties at 300mm centres to prevent dislocation during installation. The ends of pipes shall be marked to ensure that the impermeable invert is correctly positioned during installation.

8.19.7 Drilling for raking drains

(a) Drilling lubricants other than clean air or fresh water shall not be used for drilling holes for raking drains. Casings shall be used to prevent collapse of the hole and to permit unobstructed insertion of the pipes and geotextile filter sheath.

(b) The drillhole entry point shall be positioned within a tolerance of ±75 mm. Deviation

in alignment shall not exceed 1 in 20. Deviation from straight shall not exceed 20 mm in any 3 m length of drillhole. A positive gradient shall be maintained throughout the complete length of the hole. The inclination of holes shall be measured by a method reviewed without objection by the Project Manager.

(c) Drilling and sampling for undisturbed soil samples and rock cores directed by the

Project Manager to be recovered from drillholes shall be as stated in Clauses 8.5.6 to 8.5.19.

(d) Drillholes shall be temporarily plugged or otherwise protected to prevent entry of

deleterious material after drilling. 8.19.8 Excavation for trench drains

The width of trench drains shall be at least 450 mm. The width of trench drains with filter pipes not exceeding 150 mm diameter shall be at least four times the nominal diameter of the pipe. The width of trench drains for pipes exceeding 150 mm diameter shall be at least the same as the external diameter of the pipe plus 450 mm.


8.19.9 Geotextile filter surround for trench drains

Geotextile filter surround for trench drains shall be installed as stated in Clause 8.19.4. 8.19.10 Bed for trench drains

(a) Concrete bed for filter pipes in trench drains shall be at least 75 mm thick and shall be

Grade 20/20 concrete. (b) Granular bed for filter pipes for trench drains shall have a thickness at least the same

as the diameter of the pipe or 150 mm, whichever is greater. 8.19.11 Deposition and compaction of fill material for trench drains

(a) The material for granular bed for trench drains shall be deposited in the trench in layers not exceeding 150 mm thick and for the complete width of the trench. Each layer shall be compacted with six passes of a plate vibrator or by other method reviewed without objection by the Project Manager.

Trench drains shall be backfilled with Type A or Type B material of Table 8.2. Type A or Type B material shall consist of hard, clean, crushed rock, crushed slag or gravel having a grading within the limits of Table 8.2. The aggregate crushing value of the material shall not exceed 30 per cent. The material passing the 425 m BS sieve shall be non-plastic when tested in accordance with BS 1377.

(b) Fill material around filter pipes in trench drains shall be deposited and compacted as stated in Clauses 7.4.20(b) and (c) and 7.4.27. The Project Manager shall be notified before fill material is deposited around filter pipes.

8.19.12 Fixing relief drains

Relief drains shall be fixed in position before surface protection or remedial measures are applied. Fixing shall be carried out in a manner which will not affect the serviceability of the relief drains or outlets. Water collected in relief drains shall be discharged to outlets reviewed without objection by the Project Manager.

8.19.13 Construction of caisson drains

(a) Excavation for caisson drains shall be carried out by manual methods in stages not

exceeding 1.0 m depth. Dewatering shall be carried out for excavation below the groundwater level so that work shall be carried out, as near as practicable in the circumstances, in dry conditions. Dewatering shall be carried out as stated in Clauses 8.19.16 and 8.19.17.

(b) The caisson drain shaft shall be supported at all times during construction using

concrete liners. Voids between liners and excavated faces shall be filled with no fines concrete. Caisson liners for each 1.0 m stage shall be installed on the same day as that stage is excavated.

(c) Softened and loose material shall be removed from the base of the caisson drain

immediately before granular filter material is deposited in the caisson drain. (d) Part or all of the concrete liner adjacent to the granular filter layer shall be removed

before granular filter material or fill material is deposited. Debris from the concrete liner shall be removed from the caisson drain.


(e) Granular filter material shall be deposited in layers not exceeding 500 mm and shall be compacted by methods reviewed without objection by the Project Manager.

8.19.14 Discharge of water from caisson drains

Water collected in caisson drains shall be discharged to the outlets stated in the Contract or reviewed without objection by the Project Manager

8.19.15 Installation of prefabricated band drains

(a) The installed location of prefabricated band drains shall be within 300 mm of the specified location in plan on the ground surface and the drain shall be within 2% of the installed length to the vertical.

(b) Each prefabricated band drain shall be installed in one continuous length without

joints. (c) The depth of penetration of prefabricated band drains shall be as stated in the

Contract, modified as directed by the Project Manager during installation based on the resistance of the soil to penetration. The Contractor shall notify the Project Manager immediately of any sudden change in the penetration resistance to the mandrel.

(d) Augering, hammering, vibration or other methods may be used to assist vertical drain

installation through the filter drains and the reclamation fill. Such augering, hammering, vibration or other methods shall not extend into the underlying marine clay stratum.

(e) Where obstructions above the marine clay stratum are encountered which cannot be

penetrated using normal and accepted procedures mentioned above, the Contractor shall complete the drain from the elevation of the obstruction to its top level and notify the Project Manager. At the discretion of the Project Manager, the Contractor shall then install a new drain at a location as directed by him.

(f) The Contractor shall keep daily records of the drains installed. Copies of these shall be

submitted to the Project Manager on the day following the installation. The records shall give the date, the reference no. of each drain and the depth of placement below its top level. Brief notes on any unexpected conditions or problems encountered shall be included.

8.19.16 Drawdown of groundwater table

The groundwater table shall not be drawn down to more than 2 m below the earthworks final surface as defined in Clause 7.1.2 for excavation.

8.19.17 Dewatering

(a) Dewatering shall be carried out in such a manner that no loss of fines from the ground occurs.

(b) Silt traps shall be provided and shall be regularly maintained; all dewatering pumps

shall discharge into silt traps.


(c) Pumped groundwater shall not be discharged onto roads, footpaths, kerb channels or adjacent land. The Contractor shall make all arrangements with, and obtain the necessary approvals and consents from the Relevant Authorities and the Project Manager for discharging water to drainage systems, watercourses or the sea. Dewatering shall not start until the permitted arrangements for disposal of the water have been implemented. Water entering the Site shall not be discharged into the same silt traps as are used for dewatering.

(d) The total capacity of pumps available on the Site for dewatering shall be at least equal

to twice the rate of flow measured through the silt traps at any time when the groundwater table is maintained at maximum drawdown.

(e) Half of the total pump capacity shall be equipped with a secondary motive power

source in addition to the primary motive power. The secondary motive power source shall commence operation automatically in the event of failure of the primary motive power source or an effective alarm system shall be set up which will warn of failure of the primary motive power source. The maximum allowable delay between failure of the primary motive power source and full operation of the secondary motive power source shall not exceed 15 minutes.

(f) A full-time attendant shall be available on the Site at all times to execute the

changeover if manual operation of equipment is required to bring the secondary motive power into operation.

(g) The operation of the changeover of motive power equipment shall be demonstrated

before the relevant work starts. 8.19.18 Groundwater recharge

(a) If groundwater recharge is to be carried out to maintain the specified groundwater levels at any location, the groundwater recharge system shall have the means to regulate and measure the rate of recharge and to provide an adequate continuous supply of water for recharge. Only clean fresh water shall be used.

(b) The capacity of pumps and the power sources which are to be used for groundwater

recharge shall be as stated in Clause 8.19.17(d) except that the rate of flow shall refer to the maximum rate of groundwater recharge required.

(c) The groundwater table at any location shall not be raised above the background

groundwater table measured before the relevant work starts. 8.19.19 Monitoring of groundwater control and drawdown

(a) Monitoring of groundwater levels shall be carried out at locations stated in the Contract or instructed by the Project Manager at all times when groundwater control and drawdown is carried out. Arrangements for installing instruments and taking measurements both inside and outside the Site shall be made by the Contractor.

(b) The survey marks for monitoring shall be located in position and level to the Hong

Kong standard survey grid and to PD to within 10 mm in every direction. (c) Monitoring stations and monitoring shall be as stated in Clauses 8.21.1 to 8.24.11. (d) Groundwater levels shall be measured to an accuracy of 20 mm. Settlements shall be

measured to an accuracy of 3 mm.


(e) The Contractor shall notify the Project Manager immediately if any increment settlement reading exceeds 5 mm or if the accumulated settlement exceeds the maximum allowable settlement stated in the Contract.

8.20 INSPECTION, TESTING AND COMMISSIONING – GROUNDWATER

DRAINAGE AND CONTROL 8.20.1 Records of geotextile filter

Records of installation of geotextile filter shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review each day. Records shall contain the following details:

(a) identification of structures and sections of work where geotextile filter is installed; (b) type of geotextile filter, including identification of batch; (c) date of first exposure of geotextile filter to ultra-violet radiation before installation; (d) type of joint, amount of overlap, method of holding in place and any repairs to

geotextile filter carried out during installation; (e) date of installation of geotextile filter; and (f) date of final covering of geotextile filter.

8.20.2 Records of drillholes for raking drains

Records of drillholes for raking drains shall be kept by the Contractor on Site and a drillhole log for each drillhole shall be submitted to the Project Manager for review before installation of the raking drain starts. The borehole log shall contain the following details:

(a) drain reference number; (b) location, inclination, bearings, diameter and length of hole; (c) details of drilling progress; (d) details of water seepage related to drilling progress; and (e) details of samples taken.

8.20.3 Trials for relief drains A trial length of relief drains of at least 2 m shall be constructed.


8.20.4 Records of caisson drains

(a) Records of caisson drains shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 14 days after completion of construction of caisson drains. The records shall contain the following details:

(i) record of work carried out each day; and

(ii) drawings showing the exact locations of caisson drains and the final depths

relative to PD.

(b) Detailed face logs of caisson drains shall be kept by the Contractor on Site and shall be available for inspection by the Project Manager at all times. The logs shall contain the information required in Clause 8.5.5(b)(ii), (b)(iii) and (b)(iv) and the format shall be as shown in Figure 10 of 'Geoguide 2: Guide to Site Investigation', Hong Kong Government 1987.

8.20.5 Records of settlement, groundwater control and drawdown

Records of monitoring of settlement, groundwater control and drawdown shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 24 hours of taking readings.

8.20.6 Batch: granular filter material

A batch of granular filter material is any quantity of granular filter material of the same type and grading delivered to Site at any one time.

8.20.7 Samples: granular filter material

(a) One sample of granular filter material shall be provided from each 500 m3 or part thereof of the material delivered to Site.

(b) One sample of granular material shall be provided from each 500 m3 or part thereof of granular filter material which has been deposited and compacted.

(c) The size of each sample taken as stated in Clause 8.20.7(a) shall be 10 kg. The

method of sampling shall be in accordance with BS 812:Part 102. (d) Samples taken as stated in Clause 8.20.7(b), shall consist of material excavated from

the compacted layer to form a flat bottomed, steep sided hole of approximately 0.13

m² to the complete depth of the compacted layer; a template shall be used to fix the edges of the hole if necessary. The sides and bottom of the hole shall be at least 50 mm from other types of fill material.

8.20.8 Testing: granular filter material

(a) Each sample of granular filter material shall be tested to determine the particle size distribution.

(b) The method of testing shall be in accordance with the wet sieving method stated in

GEO Report No. 36, Test 2.9.2B.


8.20.9 Non-compliance: granular filter material

(a) If the result of any test for particle size distribution on a sample of granular filter material taken as stated in Clause 8.20.7(a) does not comply with the specified requirements for particle size distribution, additional samples shall be provided from the same batch and additional tests for particle size distribution shall be carried out.

(b) The batch shall be considered as not complying with the specified requirements for

particle size distribution if the result of any additional test for particle size distribution does not comply with the specified requirements for particle size distribution.

(c) If the result of any test for particle size distribution on a sample of granular filter

material taken as stated in Clause 8.20.7(b) does not comply with the specified requirements for particle size distribution, additional samples shall be provided from the same batch and additional tests for particle size distribution shall be carried out.

(d) The batch shall be considered as not complying with the specified requirements for

particle size distribution if the result of any additional test for particle size distribution does not comply with the specified requirements for particle size distribution.

8.20.10 Batch: fill material for trench drains

A batch of fill material for trench drains is any quantity of fill material for trench drains of the same type delivered to Site at any one time.

8.20.11 Samples: fill material for trench drains

(a) One sample of fill material for trench drains shall be provided from each batch of fill

material for trench drains delivered to Site. (b) The size of each sample and the method of sampling shall be in accordance with

Clause 8.20.7(c). 8.20.12 Testing: fill material for trench drains

(a) Each sample of fill material for trench drains shall be tested to determine the particle size distribution; fill material passing a 425 m BS test sieve shall also be tested to determine the plasticity index.

(b) The method of testing to determine the particle size distribution shall be in accordance

with GEO Report No. 36, test 2.9.2B. The method of testing to determine the plasticity index shall be in accordance with GEO Report No. 36, tests 2.4.3 and 2.5.3.

8.21 DEFINITIONS AND ABBREVIATIONS - GEOTECHNICAL INSTRUMENTATION 8.21.1 Datum station Datum station is a mark for which horizontal or vertical values, or both, have been fixed,

and which is used as a datum for monitoring or control surveys.


8.21.2 Geotechnical instrumentation

Geotechnical instrumentation is the installation and monitoring of instruments in the ground or structures to provide information on soil and rock parameters, and to monitor specific variations in the condition of the ground or structures for the purposes of geotechnical design, construction control and performance monitoring.

8.21.3 Monitoring mark

Monitoring mark is a mark, fixed or installed, on a structure to be monitored. 8.21.4 Reference point

Reference point is a mark placed close to another important survey mark to aid recovery or replacement.

8.21.5 Survey station

Survey station is a mark on a stone, concrete, metal or wooden block, pipe, peg or other item defining a surveyed position.

8.22 MATERIALS – GEOTECHNICAL INSTRUMENTATION 8.22.1 Instruments for geotechnical instrumentation

(a) Instruments for geotechnical instrumentation and their accessories shall be provided complete with all appropriate tubing, connections, monitoring equipment, read-out units and any other tools necessary for the installation, calibration, setting to work and maintenance of the instruments.

(b) Instruments shall be manufactured by companies with proven experience and only

instruments which are well proven and have been in successful use shall be used. (c) Instruments shall be handled, stored, installed and used in accordance with the

manufacturer's recommendations and in such a manner that the performance of the instruments will not be impaired.

(d) Instruments shall be protected from damage and measures shall be taken to ensure

that the instruments suffer the minimum practicable amount of disturbance. (e) Instruments shall be calibrated by a laboratory reviewed without objection by the

Project Manager. Instruments shall be calibrated at intervals recommended by the manufacturer and at other intervals directed by the Project Manager. Calibration certificates shall be provided to the Project Manager for review within 24 hours after calibration.

(f) Installation, testing and monitoring of the instruments shall be carried out under the

supervision of a suitably qualified geotechnical engineer who shall have a minimum of five-years experience of the installation and monitoring of field instrumentation. Particulars of the geotechnical engineer, including qualifications and experience, shall be submitted to the Project Manager for review.


8.22.2 Standpipe piezometers

Standpipe piezometer tips for geotechnical instrumentation shall be porous ceramic or plastic material at least 200 mm long and with a bore of at least 19 mm. Permeability shall

be at least 10-4 m/s. The piezometer tip shall be connected to rigid PVC standpipes with a bore of at least 19 mm and with a wall thickness of at least 3 mm. The standpipes shall be jointed together and to the porous tips in such a manner that the joints remain leak-proof under the anticipated head of water.

The general layout of the apparatus shall conform to the details shown in Geoguide 2 Figures 19 and 21.

8.23 SUBMISSIONS – GEOTECHNICAL INSTRUMENTATION 8.23.1 Particulars of geotechnical instrumentation

(a) The following particulars of the proposed geotechnical instrumentation shall be submitted to the Project Manager for review:

(i) details of instruments ;

(ii) manufacturer's specifications;

(iii) test and calibration certificates;

(iv) method of installation;

(v) method of acceptance testing;

(vi) details of ancillary measuring equipment;

(vii) schedule for installing instrumentation in relation to progress of the Works;

(viii) documents showing that the instruments are capable of measuring within the

ranges and accuracies stated in the Contract;

(ix) name and experience of persons responsible for installation, testing and monitoring of instruments;

(x) details of standpipe piezometer tips, including manufacturer's specification; and

(xi) details of the form of records.

8.24 WORKMANSHIP – GEOTECHNICAL INSTRUMENTATION 8.24.1 Location and arrangement of instruments

(a) The locations and arrangement of instruments for geotechnical instrumentation shall be as stated in the Contract or as reviewed without objection by the Project Manager before installation.


(b) The positions and alignments of instruments shall be recorded after installation and surveys shall be carried out at times and frequencies reviewed without objection by the Project Manager to detect any displacement of the instruments.

(c) At least two reference points shall be established for each survey station or

monitoring mark. (d) The survey station which has the least chance of being disturbed shall be selected as

datum station. The datum station shall be stainless steel. At least three reference points shall be established for each datum station.

(e) The survey network shall be related to the master survey stations provided by the

Project Manager. 8.24.2 Installation of instruments

(a) The Contractor shall notify the Project Manager before the installation of each instrument for geotechnical instrumentation starts.

(b) Tests shall be carried out after installation to demonstrate that the instruments have

been correctly installed and are functioning correctly. Instruments which are not correctly installed or are not functioning correctly shall be reinstalled or replaced as directed by the Project Manager.

(c) All installed instruments, tubes and wires shall be clearly marked with a unique and

conspicuous identification number. 8.24.3 Tubes and cables for instruments

(a) Tubes and cables attached to instruments for geotechnical instrumentation for remote reading shall be impervious to air and water, and shall have sufficient strength and stiffness to withstand the internal and external pressures. Tubes and cables shall be protected from mechanical damage and from the harmful effects of direct sunlight, heat and ultra violet radiation at all times.

(b) Tubes and cables shall be marked with identification colours and numbers at 5 m

intervals. The tubes and cables shall be wound onto reels in such a manner that kinks are not formed and strain is not induced. Open ends of tubes and cables shall be blocked with stop ends at all times.

(c) Tubes and cables shall be buried at least 0.5 m below ground level. (d) Tubes and cables shall be laid with sufficient slack, loops and bends to allow for

settlement and other ground movements. The routing of tubes and cables shall be as reviewed without objection by the Project Manager. The radius of bends shall be at least 300 mm. Each tube or cable shall be laid from the measuring instrument to the terminal duct in one continuous length without joints.

8.24.4 Maintenance of instruments

(a) Instruments for geotechnical instrumentation shall be maintained in good working order until the expiry of Defects Liability Period. Instruments, survey marks and stations shall be protected by suitable barricades, notices, signs or marker-buoys.

(b) The Contractor shall notify the Project Manager immediately of any instruments

found damaged or instruments found not to be in working order. Replacements shall be installed for read-out units which are faulty or under repair.


8.24.5 Records of geotechnical instrumentation

(a) Records of activities relating to installation of geotechnical instrumentation shall be kept by the Contractor on Site and a copy shall be submitted to the Project Manager for review within 24 hours after installation of the instrument is complete.

(b) Contractor’s Drawing showing the locations and identification of installed

instruments shall be submitted to the Project Manager for review within 24 hours after installation of the instrument is complete.

(c) Contractor’s Drawing showing the locations and details of survey stations, monitoring

marks and reference points shall be submitted to the Project Manager for review within 3 days after the survey network has been established.

8.24.6 Recording readings

(a) Instrument readings and processed data for geotechnical instrumentation shall be recorded by the Contractor on agreed record sheets, and shall be submitted to the Project Manager for review within 24 hours after recording. The form of record sheets shall be as reviewed without objection by the Project Manager. Readings shall be taken in the presence of the Project Manager.

(b) Initial readings shall be taken immediately after the instruments have been installed

and after the effects of installation have subsided. The initial readings shall be submitted to the Project Manager for record and shall form the basis of comparison of subsequent readings. The instruments and the initial readings shall be replaced if the initial readings are not repeatable.

(c) The frequencies for reading instruments shall be as reviewed without objection by the

Project Manager. The Contractor shall notify the Project Manager immediately of sudden or significant changes in the readings.

(d) All installed instruments shall be left in correctly functioning condition after final

readings have been taken or at the end of the Defects Liability Period. Keys for locks shall be tagged to identify the instrument number and shall be handed over to the Project Manager.

8.24.7 Installation of settlement plates

(a) Settlement plates for geotechnical instrumentation shall be securely founded on level ground free from obstructions and shall be immediately surveyed for level and position and plotted on a plan.

(b) Settlement plates shall be protected from damage and shall be kept in position by a

600 mm thick layer of granular fill material or bags of sand which shall be placed by manual methods and shall extend 600 mm beyond the edges of the plate. The initial survey of levels and positions shall be taken immediately after the fill material or bags of sand have been placed.

(c) The metal rod fixed to the centre of the plate shall be in an upright position, and

protected by a tubular sleeve. The sleeve and the metal rod shall be extended as fill material is placed such that at any time the sleeve and rod are at least 500 mm above the level of the surrounding fill material or high water mark, and the metal rod is within 2% of the embedded length to the vertical.


(d) The level of the top of the metal rod shall be recorded immediately before and immediately after each extension piece is added. Marker-buoys shall be fixed to the tops of tubular sleeves installed in water.

8.24.8 Installation of tiltmeter system

(a) Tilt-plates for geotechnical instrumentation shall be orientated to correspond with the specified direction of measurement and fixed in place on the rock or structure. The installed direction shall be recorded to an accuracy of ±3°.

(b) A protective cap or cover shall be fitted to protect the tilt-plates from damage. (c) Tilt-plates and the tiltmeter shall be cleaned and inspected for damage before readings

are taken. The tiltmeter shall be accurately located on the tilt-plate and a reading taken. The tiltmeter shall then be removed and the contact surface recleaned. The procedure shall be repeated until consistent readings are obtained. The tiltmeter shall then be rotated through 180° and the procedures repeated.

(d) The accuracy of the tiltmeter and its readout system shall be checked both before and

after the readings taken each day. Instrument errors shall be investigated and immediately corrected; a record of calibrations and adjustments shall be submitted to the Project Manager for review together with the monitoring data.

8.24.9 Installation of telltales

Telltales for geotechnical instrumentation shall be as shown in Figure 10.5 of 'The Geotechnical Manual for Slopes', Hong Kong Government, 1984. Telltales shall be rigidly fixed across cracks to enable any movement across the cracks to be determined. Telltales shall be labeled and marked with the date of installation.

8.24.10 Installation of standpipe piezometers

(a) Standpipe piezometers for geotechnical instrumentation shall be installed in drillholes at the depths as stated in the Contract or as directed by the Project Manager.

(b) The sand filter surrounding the piezometer tip shall be between 1000 mm and 1500

mm long and shall consist of sand between the sizes of 200 m and 1210 m. Measurements shall be made to determine the actual location of the sand filter column.

(c) A seal shall be formed above the sand filter by placing 500 mm of bentonite pellets of

between 10 mm and 15 mm in size. The pellets shall be placed in the hole and tamped with a suitably shaped tamper to form a homogeneous plug to the hole.

(d) If the depth of the completed hole is greater than the depth at which the piezometer tip

and sand filter are to be placed, the bottom of the drillhole shall be grouted with grout consisting of cement and bentonite in the proportions 1:1 by mass together with sufficient water to achieve the required workability. The drillhole above the plug shall be grouted with the same type of material.

(e) The water level in the piezometer shall be measured after the standpipe piezometer has been installed and the standpipe shall be topped up with clean water. The rate of drop of water level or pressure head shall be recorded at times of 0, 1/4, 1/2, 1, 2, 4, 8, 15, 30 minutes or until the water has returned to its initial level.


(f) The water level shall be measured by an electrical type water level probe reviewed without objection by the Project Manager. The water may be salted if necessary for response to the probe.

(g) Measurements of the depth of piezometer tip and sand filter and the readings taken as

stated in Clause 8.24.10(f) shall be submitted to the Project Manager for review within 24 hours after completion of installation of the piezometer standpipe.

(h) Surface boxes as shown in Geoguide 2 Fig 21 shall be constructed within 2 days of

completion of the piezometer installation and backfilling of the hole. (i) The hole reference number shall be permanently inscribed on the surface box either

by welding a numbered steel plate to the box cover or by inscribing the number in the concrete surround.

8.24.11 Observation wells

(a) Where shown on the Employer’s Drawings or as otherwise instructed by the Project Manager, the Contractor shall provide and install an observation well.

(b) The observation well shall consist of rigid PVC tubing to the dimensions and

installation details as described in Clause 8.24.10 except that the tube shall be capped at its lower end and perforated with 6 mm diameter holes for a minimum of 5% of its surface area over a length of 1.5 m or as instructed by the Project Manager. The upper end of the tube shall be set in concrete and fitted with a surface box as shown in Geoguide 2 Figure 21. The perforated length shall be wrapped with two layers of nylon mesh. The granular surround to the perforated length shall be 10 to 16 mm washed aggregate.

(c) The elevation of the base and the top of the granular surround shall be recorded on the

log. The depth to the base of the observation well shall be confirmed by dipping on completion of the installation.

8.25 GENERAL - LABORATORY WORK 8.25.1 General

(a) The Contractor shall, when instructed by the Project Manager, carry out soil tests specified in this Section at a HOKLAS accredited laboratory reviewed without objection by the Project Manager.

(b) The laboratory shall hold current HOKLAS accreditation for all Phase 1 tests as

listed in Works Branch Technical Circular No 6/94 “Soil Testing Standard (Phase 1 Tests)”. Accreditation of the Phase 1 tests shall be according to GEO Report No 36, “Methods of Test for Soils in Hong Kong for Civil Engineering Purposes (Phase 1 Tests).

(c) The “Laboratory Work” shall be completed within four weeks of the completion of

the “Field Works”.

8.25.2 Work on General Holidays

No testing shall be carried out on general holidays without permission in writing by the Project Manager.


8.25.3 Contractor’s supervision

Laboratory testing shall be carried out under the continuous supervision of a competent engineer or senior technician who is experienced in soils testing procedures. This person shall certify the accuracy, correctness and completeness of the test results supplied to the Project Manager by the Contractor.

8.25.4 Staff - definitions

For laboratory testing the following definitions shall apply:- Senior technician - a person with at least 10 years experience gained in a soil testing laboratory and fully familiar with triaxial testing procedures.

8.25.5 Results, samples and original sample containers property of the Employer

The results of the tests shall become the property of the Employer and shall not be divulged by the Contractor except to the Employer or the Project Manager. Samples and the original sample containers are the property of the Employer and the Contractor shall not dispose of any samples, original sample containers or parts thereof except as directed by the Project Manager.

8.26 WORKMANSHIP – LABORATORY WORK 8.26.1 Extrusion of ‘Mazier’ samples for testing

For testing purposes, 'Mazier' samples shall be cut to the appropriate length for testing and then extruded in the direction of the top of the sample in a manner reviewed by the Project Manager.

8.26.2 Retention of samples

When laboratory tests are carried out on only part of a soil sample, the remainder of the soil in the sampler or container shall be resealed with wax as soon as possible and retained. Soil on which laboratory tests have been carried out, including that wasted during the preparation of test specimens, shall be retained in airtight containers until the presentation of the “Final Report”.

8.26.3 Classification and chemical test procedures

The following laboratory soil classification tests shall where applicable be carried out in accordance with the procedures described in BS 1377 except where indicated below:

(a) determination of moisture content (GEO Test 2.3.2A or 2.3.2B as appropriate: GEO

Report No 36 - Methods of Test for Soils in Hong Kong for Civil Engineering Purposes (Phase 1 Tests));

(b) determination of liquid limit (GEO Test 2.4.3). The sample shall not be completely

dried before testing; (c) determination of plastic limit, plasticity index and liquidity index (GEO Test 2.5.3).

The soil shall not be completely dried before testing;


(d) determination of particle density for soils containing gravel sized particles (BS 1377 Part 2 Method 8.2). Samples at natural moisture content of dry weight approximately equal to that specified in BS 1377 shall be used. The sample shall not be dried prior to testing but shall be oven dried and weighed on completion of the test. The test shall be carried out using distilled water; and

(e) determination of particle size distribution on:

(i) essentially cohesionless soil down to the fine sand size (GEO Test 2.9.2A

Method A or Method B as appropriate); and

(ii) coarse sand to clay size (GEO Test 2.9.5A).

8.26.4 Triaxial test procedures “Triaxial Test Procedures” as specified in Clauses 8.26.5, 8.26.21 and 8.26.22 shall be based upon "The Measurement of Soil Properties in the Triaxial Test" (Second edition, 1962) by A.W. Bishop and D.J. Henkel, unless otherwise instructed by the Project Manager.

8.26.5 Use of ceramics

When necessary, as determined by the Project Manager, high air-entry ceramics shall be used to separate the soil specimen from the base drain (Bishop and Henkel p. 221). For any test where pore pressure is measured from the top of the specimen, it shall be permissible to use low air-entry ceramics for separating the specimen from the top cap. Porous ceramics shall be de-aired (Bishop and Henkel p. 185).

8.26.6 Calibration of pressure gauges

Equipment capable of providing and maintaining steady cell pressures of up to 850 kPa shall be used. Pressure gauges (i.e. those used for cell pressure, pore pressure and back pressure measurements) shall be calibrated against an accurate dead load tester or alternative method agreed by the Project Manager unless calibrated within the three months preceding the start of any test. The Contractor shall provide the Project Manager with calibration charts showing the corresponding values of the dead weight tester(s) and the pressure gauges. Results shall be presented in increments of 50 kPa up to and including 850kPa. Calculations shall be based on the pressure gauge readings reduced to their calibrated values.

8.26.7 De-aired water De-aired water shall be used to saturate soil specimens and for cell water. Adequate provision shall be made at any air/water interfaces in the pressure application system to minimise air contamination of the water.

8.26.8 Specimen diameter

The size of specimen to be tested shall normally be 76 mm in diameter. Test specimens shall be prepared from undisturbed samples (Bishop and Henkel p. 83), or disturbed samples compacted or remoulded at a specified moisture content to a specified density (Bishop and Henkel p. 87) in a manner reviewed by the Project Manager.


8.26.9 Jacketing gritty soils

In the case of gritty soils two membranes shall be used for jacketing the soil specimen, unless agreed otherwise with the Project Manager. Membranes shall be checked for leakage before use.

8.26.10 Saturation of specimens by back-pressure

Test specimens shall be saturated by the application of back-pressure before the consolidation stage. The saturation procedure shall be as follows:-

(a) application of an undrained 50 kPa increment in cell pressure (3). Adequate time

shall be allowed for pore-water pressure response (u) to stabilise. If the ratio u/3 (hereafter called B) is less than 0.97 or as decided by the Project Manager, then

(b) the back-pressure shall be brought up to the value of the cell pressure minus 5 kPa

with the drain closed. The drain shall then be opened and the volume change shall be noted and adequate time shall be allowed for this change to cease. Procedure (1) shall then be repeated.

If B exceeds 0.97, then

(c) the cell pressure shall be taken up in undrained increments of 50 kPa or less to the

value of the test cell pressure allowing pore water stabilization at each increment, and the pore water pressure shall be recorded immediately after application of each additional increment of pressure.

8.26.11 Saturation by flooding

When instructed by the Project Manager samples shall be saturated by flooding. The procedure for single-stage and for the first stage of multi-stage testing shall be as follows:- (a) if saturation by back-pressure has been attempted, the cell pressure shall be reduced to

50 kPa and simultaneously the back-pressure shall be reduced to 40 kPa. If saturation by back-pressure has not been attempted, cell pressure shall be set at 50 kPa and back-pressure at 40 kPa; and

(b) maintaining these pressures, the drain shall be opened from the sample top cap to the

atmosphere and de-aired water shall be allowed to flow through the sample until bubbling ceases. The drain shall then be closed and the sample saturated by back-pressure as specified in sub-clause (a) above.

8.26.12 Corrections to be applied to the value of deviator stress

The following corrections, where appropriate, shall be applied when calculating the deviator stress and shall be indicated in the results:-

(a) change in cross-sectional area (Bishop and Henkel, p. 28); (b) restraint from the rubber membrane and filter paper drains (Bishop and Henkel, p.

167); and (c) friction on the loading ram (Bishop and Henkel, p. 174).


8.26.13 Definition of shear failure

Shear failure for single stage triaxial tests shall be defined in terms of maximum principal stress difference (1 - 3). Shear failure for multi-stage triaxial tests shall normally be defined in terms of maximum principal effective stress ratio (1'/3') unless otherwise instructed by the Project Manager.

8.26.14 Shear plane failure

For specimens which fail along a shear plane, the axial strain at which the shear plane becomes apparent shall be recorded.

8.26.15 Required sketches of specimen failure

A sketch shall be made of the mode of specimen failure. The angle of any distinct shear planes shall be measured with respect to the horizontal and noted both before splitting and after splitting the specimen.

8.26.16 Consolidated-undrained single-stage triaxial tests (a) “Consolidated-undrained Single-Stage Triaxial Tests” (Bishop and Henkel (1962) pp.

106 and 192) shall be carried out with pore-water pressure measurement and using back-pressure for saturating the sample. At the end of the consolidation stage a suitable rate of axial strain shall be agreed with the Project Manager to ensure that the results obtained shall lead to a true measure of the physical properties of the soil. The rate shall be sufficiently low to ensure equalisation of pore-water pressure throughout the specimen and shall not exceed 0.2 mm/min.

(b) The report of each test shall include the following information:-

(i) sample and specimen number;

(ii) location and depth of the sample;

(iii) description of the test specimen;

(iv) method of preparation and dimensions of the specimen;

(v) initial and final moisture content, volume and bulk density and specified effective cell pressure;

(vi) pore-pressure parameter B for each increment of back-pressure;

(vii) maximum pore-pressure parameter Bmax (being the maximum B value

calculated for the 50 kPa increments in cell pressure);

(viii) final back-pressure;

(ix) standard increment of cell pressure (50 kPa, unless otherwise specified by the Project Manager); and

(x) final value of pore-water pressure generated by the final undrained increment in

cell pressure;


Consolidation:

(xi) volume change/square-root of time plot; and

(xii) computed coefficient of consolidation, coefficient of permeability and coefficient of volume compressibility;

Shearing Stage:

(xiii) rate of axial strain;

(xiv) deviator stress/axial strain plot;

(xv) principal effective stress ratio/axial strain plot;

(xvi) pore water pressure/axial strain plot;

(xvii) maximum deviator stress and corresponding axial strain;

(xviii) maximum principal effective stress ratio and corresponding axial strain;

8.26.17 Consolidated-undrained multi-stage triaxial tests “Consolidated-Undrained Multi-Stage Triaxial Tests” shall be carried out in 3 stages with pore-water pressure measurement in accordance with procedures defined in the Clause 8.26.16 relating to single-stage tests except that:-

(a) B values recorded during saturation by back-pressure shall be determined as described

in Clauses 8.26.10 or 8.26.11 and in addition by measuring the u/3 ratio as the cell pressure is increased between stages.

(b) If failure has not occurred in a particular stage, shearing for that stage shall be stopped

at the following cumulative strains, subject to the Project Manager’s agreement:

(i) initial loading 15%;

(ii) second loading 20%; and

(iii) third loading 25%.

8.26.18 Consolidated-drained single-stage triaxial tests

(a) “Consolidated-Drained Single-Stage Triaxial Tests” (Bishop and Henkel, pp. 124 and 204) shall be carried out as directed by the Project Manager. At the end of the consolidation stage the Contractor shall calculate a suitable rate of axial strain acceptable to the Project Manager. This rate shall be sufficiently low as to ensure at least 95 per cent dissipation of excess pore-pressure at failure.

(b) The report of each test shall include the requirements listed in Clause 8.26.16(b)

together with a volume change/axial strain plot.


8.26.19 Unconsolidated-undrained triaxial tests

(a) “Unconsolidated-Undrained Single-Stage Triaxial Tests” without the measurement of pore-water pressure shall be carried out using back-pressure for saturating the sample. The tests shall be carried out in accordance with Part 7 Method 8 of BS 1377.

(b) The report of each test shall include the following information:

(i) sample and specimen number;

(ii) location and depth of the sample;

(iii) description of the test specimen;

(iv) method of preparation and dimensions of the specimen;

(v) initial and final moisture content, volume and dry/bulk density;

(vi) specified effective cell pressure;

(vii) pore-pressure parameter B for each increment of back-pressure;

(viii) maximum pore-pressure parameter Bmax (being the maximum B value calculated for the 50 kPa increments in cell pressure);

(ix) final back-pressure;

(x) standard increment of cell pressure (50 kPa, unless otherwise specified by the

Project Manager); and

(xi) final value of pore-water pressure generated by the final undrained increment in cell pressure; and

(xii) Shearing Stage:

(xiii) rate of axial strain;

(xiv) deviator stress/axial strain plot; and

(xv) maximum deviator stress and corresponding axial strain.

8.26.20 Plotting of results

A Mohr stress circle diagram shall be prepared for results of a series of tests on the same sample or for results of one multi-stage test providing plastic failure has occurred in each specimen or planar failure has been on planes included at approximately (45 degrees +0/ '/2) to the horizontal. The apparent cohesion (c') and angle of shearing resistance (0/ ') with respect to changes in effective stress shall be determined by the "least-squares" fitting technique. For failure of specimens on planes not inclined at an angle of approximately (45 degrees +0/ '/2) to the horizontal, the Project Manager shall decide on the mode of presentation of the results.


8.26.21 Photographing of triaxial test specimens

(a) A colour photographic record shall be kept of triaxial test specimens after testing. The Contractor shall take all photographs required by the Project Manager.

(b) A reference label, scale and colour chart from the manufacturer applicable to the type

of film and paper used shall be placed together with the specimen in the camera's field of view and a photograph shall be taken at a magnification agreed with the Project Manager.

(c) The photographs shall be processed so as to ensure accurate reproduction of colours,

as shown by the colour chart. One print of each photograph, and a copy of the colour chart, shall be attached to each copy of the “Draft Final Report” and to each copy of the “Final Report”. The set of negatives shall be attached to the master copy of the “Final Report”.

8.26.22 Drained modulus tests

(a) “Drained Modulus Tests” shall be carried out in a triaxial testing machine. The test specimens shall be prepared, saturated and consolidated prior to the application of axial strain in accordance with procedures relating to “Consolidated-Drained Single Stage Triaxial Tests” (Clause 8.26.18). The specimen shall then be loaded to a deviator stress as instructed by the Project Manager before being unloaded. The rate of application of axial strain during loading/unloading shall be sufficiently low to ensure at least 95 per cent dissipation of excess pore-pressure. The above loading/unloading procedures shall be repeated for four other cycles to different deviator stresses instructed by the Project Manager.

(b) The report of each test shall include the requirements given in Clause 8.26.16(b)

except that items (xiii) to (xviii) shall be replaced by:

Loading/Unloading Stage:

(i) rate of axial strain;

(ii) deviator stress/axial strain plot;

(iii) volume change/axial strain plot; and

(iv) pore-water pressure/axial strain plot. 8.26.23 Consolidated-drained shear box tests on soil

(a) Consolidated-drained single-stage and multi-stage direct shear box tests shall be carried out on samples of soil containing relict joints or discontinuities in accordance with the requirements specified in this Clause. The Contractor shall submit to the Project Manager for review:

(i) the proposed testing equipment; and

(ii) the proposed method of specimen preparation.

(b) Samples shall be handled with great care at all times. The jointed specimens shall be

prepared in such a way that shearing occurs along a continuous joint surface.


(c) After applying the initial normal pressure (30 kPa), water shall be added to the carriage to a level such that the specimen is completely immersed. Then the normal pressure shall be increased to the required value for shearing and maintained for a minimum period of 12 hours for consolidation. Any settlement of swelling taking place during the process shall be measured by dial gauge at suitable time intervals. The specimen shall be maintained in a soaked condition throughout the test.

(d) The rate of testing shall be not greater than 0.1 mm/min, and the suitability of the rate

shall be checked from consolidation stage data. Shearing shall be continued for the full travel of the shear box.

(e) Colour photographs shall be taken of all specimens before and after testing. A

reference label, scale and colour chart from the manufacturer applicable to the type of film and paper used shall be placed together with the specimen in the camera's field of view and a photograph shall be taken at a magnification agreed with the Project Manager. The photographs shall be processed so as to ensure accurate reproduction of colours, as shown by the colour chart. One print of each photograph, and a copy of the colour chart, shall be attached to each copy of the “Draft Final Report” and to each copy of the “Final Report”. The set of negatives shall be attached to the master copy of the “Final Report”.

(f) Testing shall otherwise be carried out in accordance with the procedure given in

"Laboratory Testing in Soil Engineering" by T.N.W. Akroyd. (g) Preparation of specimens for testing shall be carried out in the presence of an

experienced geotechnical engineer. (h) The report on each test shall include the following information:-

(i) sample no.;

(ii) description of the test specimen including sketches, with special attention to features such as tightness, nature of joint surface, nature of infilling material, waviness, asperities etc.;

(iii) initial and final moisture content and bulk density;

(iv) shear force/horizontal displacement plot;

(v) shear force/vertical displacement plot;

(vi) maximum shear force for each shear stage;

(vii) horizontal displacement corresponding to maximum shear force; and

(viii) when instructed by the Project Manager, a shear force/effective normal load

diagram shall be prepared corresponding to maximum shear force determined on a number of test specimens or stages from one sample, and the cohesion (c') and angle of shearing resistance (0/ ') with respect to effective stresses shall be determined.


8.26.24 Permeability tests

Falling head permeability tests (Akroyd p. 147) and constant head permeability tests (Akroyd p. 154) shall be carried out on specimens of up to 110 mm in length and diameter. The report of each test shall include the following information:-

(a) sample no.; (b) location and depth of the sample; (c) description of the test specimen; (d) method of preparation of the specimen; (e) moisture content and bulk density; and (f) coefficient of permeability.

8.26.25 California bearing ratio tests

(a) “California Bearing Ratio” (CBR) Tests shall be carried out in accordance with the procedures described in BS 1377 Part 4 Method 7. The test shall be carried out on each sample over a range of moisture contents so that the relationship of CBR to moisture content can be determined. The test shall include at least 5 determinations with moisture contents chosen from the results of the “Soil Compaction Test” and including optimum moisture content and the values of moisture content corresponding to a dry density of 95 per cent of the maximum.

(b) The results shall be recorded on forms similar to Forms 4E to 4G, BS 1377 and

acceptable to the Project Manager. 8.26.26 Soil compaction tests

(a) Soil Compaction Tests shall be carried out in accordance with the procedures described in BS 1377 Part 4 Method 3.3 or 3.4 as appropriate (2.5 Kg rammer)(at least 5 determinations per test are required).

(b) In the case of density determinations carried out at moisture contents less than the

natural moisture content in a compaction test, the soil shall not be allowed to dry to a moisture content lower than the moisture content at which the density determination is to be made.

(c) The results shall be recorded on a form similar to Form 4A, BS 1377 and acceptable to

the Project Manager. 8.26.27 One dimensional consolidation tests

“One Dimensional Consolidation Tests” shall be carried out in accordance with the procedures described in BS 1377 Part 5 Method 3. The results shall be recorded on a form similar to Forms 5A to 5D, BS 1377 and acceptable to the Project Manager.

8.26.28 Rock Compression Tests Uniaxial rock compression tests shall be conducted according to ASTM D2938-86. Test results shall be presented according to relevant ASTM Standard, or according to an alternative reviewed without objection by the Project Manager.


8.26.29 Elastic Moduli and Poisson’s Ratio of Intact Rock Elastic moduli of intact rock core specimens shall be determined according to ASTM D3148-86. Test results shall be presented according to the relevant ASTM Standard, or according to an alternative reviewed without objection by the Project Manager. A plot of compressive stress versus axial diametral strain shall also be presented.

8.26.30 Point Load Tests (a) Point load tests shall be conducted and reported according to the “Suggested Method

of Determining Point Load Strength” by ISRM (1985). Test results shall be presented according to relevant ISRM figures, or according to an alternative reviewed without objection by the Project Manager.

(b) When testing core samples, each test specimen shall first be tested with the direction

of loading perpendicular to the axis of the core (i.e. the diametral test), and secondly with the direction of loading either along the axis of the core or perpendicular to observable planes of anisotropy (i.e. the axial test). When testing irregular specimens that show anisotropy, one-half of the test specimens shall be tested with the load perpendicular to the planes of anisotropy, and the remaining half of the test specimens shall be tested with the load parallel to the planes of anisotropy.

8.26.31 Rock Joint Shear Tests

Rock joint shear tests shall be conducted according to “Suggested Methods for Determining Shear Strength” by ISRM (1974), as modified by the following: (a) rock joint shear tests shall be conducted using either a Golder or Roberston Shear

Box. The choice of shear box shall be as directed by the Project Manager;

(b) except as otherwise instructed, multi-stage tests shall be used;

(c) the following items shall be included for rock joint shear tests, with test results presented according to relevant ISRM figures, or according to alternatives reviewed without objection by the Project Manager:

(i) the dimensions of the top and bottom shear surfaces shall be determined and

recorded;

(ii) the actual area of contact between the top and bottom shear surfaces shall be estimated: areas that have regular shapes shall be calculated: areas that have irregular shapes shall be estimated using graph paper;

(iii) the roughness profile shall be recorded, before and after shear, with the aid of a

profilometer. A description of the rock joint shall also be made, including colour, tightness and nature of joint infill materials, if any;

(iv) photographs of top and bottom joint surfaces, before and after shear, shall be

taken according to Clause 8.26.21; (v) the horizontal displacements, vertical displacements, shear loads and normal

loads shall be recorded during the tests; and

(vi) the specimen shall be soaked in water overnight before testing, unless otherwise instructed by the Project Manager.


(d) the following corrections shall be made when calculating stresses:

(i) hydraulic ram springs: when hydraulic ram springs have been used a correction shall be applied to gauge readings to account for the resistance provided by the ram return springs;

(ii) cross-sectional area: the reduction in cross-sectional area during the shearing

process shall be accounted for; and

(iii) contributions to normal load, such as the self-weight of the loading system and the weight of the upper box and sample shall be accounted for.

(e) the following plots shall be prepared according to the relevant ISRM, or according to

an alternative reviewed without objection by the Project Manager:

(i) shear stresses versus horizontal displacement;

(ii) shear stresses and vertical displacement shall use the same abscissa that represents the horizontal displacement; and

(iii) peak shear stresses versus normal stress, uncorrected and corrected for dilation; and

(f) the variations to the above procedure for testing tight joints shall be as reviewed

without objection by the Project Manager. 8.26.32 Velocity of Sound in Rock

The determination of the velocity of sound in rock shall be made according to “Suggested Methods of Determining Sound Velocity” Method 1 or 2 (for P-wave and S-wave), by ISRM in “Rock Characterisation Testing and Monitoring” by E.T. Brown (editor) (1981).

8.26.33 Porosity and Dry Density of Rock The determination of porosity and dry density of rock shall be made according to “Suggested Method for Porosity/Density Determination Using Saturation and Calliper Techniques” Method 2, or “Suggested Method for Porosity/Density Determination Using Saturation and Buoyancy Techniques” Method 3, by ISRM in “Rock Characterisation Testing and Monitoring” by E.T. Brown (editor)(1981).

8.27 INSPECTION, TESTING AND COMMISSIOINING – LABORATORY WORK 8.27.1 Presentation of test results

(a) The test results shall be presented in tabular and/or graphical form as appropriate and on forms acceptable to the Project Manager. Examples of suitable forms for presentation are given in BS 1377 and also in Manual of Soil Laboratory Testing by K H Head Published by Pentech Press Limited, Graham Lodge, Graham Road, London NW4 3DG, England.

(b) Four preliminary copies of the results of each test complete with test data and

photographs shall be submitted to the Project Manager within two days of completion of the test. The records shall be legible and intelligible and shall be stamped PRELIMINARY.


8.27.2 Progress reports

Whilst laboratory testing is in progress, the Contractor shall inform the Project Manager without delay of any unusual or irregular occurrences observed during any of the laboratory tests ordered.

8.27.3 Draft final report

Within three days of completion of the “Laboratory Work” the Contractor shall submit three copies of the “Draft Final Report”. The contents and standard of presentation shall be as proposed for the “Final Report”. The presentation shall be neat, clear and intelligible. Each page, and the cover, shall be stamped “DRAFT”. The Project Manager will return one copy of the “Draft Report” to the Contractor with his comments within three weeks of receipt of the report.

8.27.4 Final report

(a) The “Final Report” shall contain the information described in the following sub-clauses relevant to the Works. In preparing the “Final Report”, account shall be taken of comments made by the Project Manager after examining the “Draft Final Report”.

The information on the cover page shall include:

(i) names of Employer, Contractor, Project Manager;

(ii) title and number of Contract; and

(iii) date of report (month and year).

The introductory text shall include:

(iv) description of Site location;

(v) dates of investigation;

(vi) methods used in making holes, taking samples and carrying out in-situ tests;

(vii) methods used in carrying out laboratory tests;

(viii) details of any bench marks and/or survey beacons to which the “Field Work” is

referenced; and

(ix) any other relevant information.

(b) The location of holes and tests shall be shown on a plan or plans of the Site. (c) Final logs and any photographs specified shall be appended. The master copy of each

final log together with the negatives of all photographs specified shall be included with the master of the “Final Report”. Logs shall be ring bound to facilitate photocopying.


(d) The results of in-situ tests shall be presented on the logs of holes and/or in tabular and/or graphical form, as appropriate. The information given shall include that provided for by the relevant test procedure in accordance with Clause 8.6.1 together with other information necessary for a full understanding of the results.

(e) The results of laboratory tests on earthworks materials shall be presented in

accordance with Section 7. The information given shall include that provided for by the relevant test procedure and any other information necessary for a full understanding of the results.

(f) Page size shall be A4. (Tables and figures shall be A4 height but greater width,

folded in such a way that the essential titles can be read without opening).

(g) One master and ten bound copies of the “Final Report” shall be submitted. (h) The “Final Report” shall be submitted within 2 weeks of the return to the Contractor

of the “Draft Report” with the Project Manager’s comments.


APPENDIX A8.1

"GEO" PROBE TEST A8.1.1 Scope This method covers the determination of the penetration resistance of soil using the GEO

probe. A8.1.2 Apparatus The following apparatus is required: (1) GEO Probe as shown in Figure 36 of 'Geoguide 2 : Guide to Site Investigation,' Hong

Kong Government 1987. The anvils shall be rigidly fixed to the guide rod, the lower anvil shall also be rigidly fixed to the extension rods. The mass of the lower anvil shall be between 1.5 kg and 1.8 kg. The combined mass of the lower anvil, guide rod and upper anvil shall not exceed 5.0 kg.

(2) Extension rods with a length of 1000 mm ±10 mm. The rods shall be attached to bear

against each other by means of external couplers. A8.1.3 Procedure The procedure shall be as follows: (1) The lower end of the probe shall be rested against the ground at the test location, with

the first extension rod and guide rod in a vertical position. (2) The hammer shall be raised to bear against the upper anvil, and shall be allowed to

fall freely. It shall not be connected to objects which may influence its acceleration and deceleration, and shall be stationary when released in the upper position. The fall shall be 300 mm ± 5 mm.

(3) The hammer shall be used to drive the probe into the ground, with a rate of driving

between 20 and 60 blows per minute. (4) Additional extension rods shall be added as necessary. The rods shall be rotated

clockwise one full turn each time a rod is added to ensure that screw joints are tight. (5) The blow count for every 100 mm of penetration shall be recorded, or at refusal the

penetration distance for 50 blows of the hammer. Interruptions exceeding 5 minutes shall be recorded.

A8.1.4 Reporting of results The following shall be reported: (1) Blow count for every 100 mm penetration or at refusal the penetration distance for 50

blows of the hammer. (2) Interruptions exceeding 5 minutes. (3) GEO probe record as shown in Figure 37 of 'Geoguide 2 : Guide to Site Investigation,'

Hong Kong Government 1987. (4) That the test was carried out in accordance with this General Materials and



APPENDIX A8.2

DETERMINATION OF THE FLOW OF GROUT

A8.2.1 Scope This method covers the determination of the flow of grout by measuring the time of efflux

of a specified volume of grout from a standard flow cone. A8.2.2 Apparatus The following apparatus is required :- (1) A flow cone reviewed without objection by the Project Manager (2) A stop watch with a least reading of not more than 0.2s. (3) A thermometer. A8.2.3 Procedure : calibration The procedure for calibrating the flow cone shall be as follows :- (1) The flow cone shall be firmly mounted in such a manner that the top will be level and

the cone will be free from vibration. (2) The discharge tube shall be closed by placing the finger over the lower end. A

quantity of 1725 mL 1 mL of water shall be introduced to the cone. (3) The point gauge shall be adjusted to show the level of the water surface. A8.2.4 Procedure : flow test The procedure for determination of the flow of the grout shall be as follows : (1) Two specimens of grout shall be taken from the sample of grout. The size of each

specimen shall be 1725 mL 1 mL. (2) The inside surface of the flow cone shall be wetted by filling the cone with water and

allowing the water to drain from the cone 1 minute before the specimen of grout is introduced to the cone.

(3) The temperature of the grout shall be recorded. (4) The discharge tube shall be closed by placing the finger over the lower end. The

specimen shall be introduced to the cone until the surface of the grout is in contact with the point gauge.

(5) The stop watch shall be started and the finger removed from the discharge tube

simultaneously.


(6) The stop watch shall be stopped at the first break in the continuous flow of grout from the discharge tube. The time shall be recorded to the nearest 0.2s as the time of efflux.

(7) The cone shall be thoroughly cleaned and the procedure stated in Clauses A8.2.3 and

A8.2.4 (1) to (6) shall be repeated for the second specimen. A8.2.5 Calculation The average time of efflux of the 2 specimens shall be calculated. A8.2.6 Reporting of results The following shall be reported : (1) The times of efflux of each specimen to the nearest 0.2s. (2) The average time of efflux to the nearest 0.2s. (3) The temperature of the specimens. (4) The ambient temperature. (5) Composition of the sample.

(6) Description of physical characteristics of the sample. (7) That the test was carried out in accordance with this General Materials and



SECTION 9 CARRIAGEWAYS : SUB-BASE MATERIAL AND BITUMINOUS MATERIALS

9.1 DEFINITIONS AND ABBREVIATIONS 9.1.1 Nominal maximum aggregate size

Nominal maximum aggregate size is the smallest BS sieve size for which the upper limit of the percentage of the aggregate by mass passing is 100%.

9.2 DESIGN AND PERFORMANCE CRITERIA 9.2.1 Design procedure for sub-base material and bituminous materials

(a) Sub-base material and bituminous roadbase materials shall be recipe mixes. Laboratory design mixes other than those for sub-base material and bituminous roadbase materials shall be made and tested as part of the design procedure at a laboratory reviewed without objection by the Project Manager.

(b) Mix designs and associated tests shall be carried out by the Contractor in the presence

of the Project Manager. The Contractor shall notify the Project Manager at least 7 days before carrying out the mix designs.

9.2.2 Design of bituminous materials

(a) Bituminous materials shall consist of coarse and fine aggregates complying with Clause 9.3.2, filler complying with Clause 9.3.3 and bitumen complying with Clause 9.3.4. The different types of bituminous materials shall have particle size distribution and bitumen content within the limits stated in Table 9.4.

(b) The properties of the different types of bituminous materials shall be as stated in Table

9.1. (c) Bituminous materials of all aggregate sizes, other than bituminous roadbase material,

shall be designed in accordance with the “Marshall Method of Mix Design” stated in The Asphalt Institute Handbook 'MS-2 Mix Design Methods for Asphalt Concrete and other Hot-mix Types,' 1984. The compaction standard shall be 75 blows per side.

(d) Design procedures for bituminous friction course material shall be as stated in Clause

9.2.2(c) except that the mixing and compaction temperatures shall be consistent with bitumen viscosities of 900 ± 100 centistokes and 2000 ± 200 centistokes respectively.


Table 9.1: Properties of Designed Bituminous Materials

Type of bituminous material Base course Wearing course Friction course

Nominal maximum aggregate size (mm) Properties

37.5 28 20 10 10 Minimum Marshall Stability (kN)

10.0 10.0 -

Maximum flow value (mm)

4.0 4.0 -

Minimum voids in mineral aggregate as a percentage of total bulk volume

12.5 13.0 14.0 16.0 25.0

Air voids in mix as a percentage of total bulk volume

3.0 - 5.0 3.0 - 5.0 18.0 - 25.0

9.3 MATERIALS 9.3.1 Sub-base material

Sub-base material shall be crushed rock and shall have the properties stated in Table 9.2. Sub-base material passing the 425 m BS test sieve, when tested in accordance with Clause 9.6.10(c) shall be non-plastic.

Table 9.2: Properties of Sub-base Material

Properties BS test sieve Percentage by mass passing

Particle size distribution 75 mm 100 37.5 mm 85 - 100 20 mm 60 - 85 10 mm 40 - 70 5 mm 25 - 45 600 m 8 - 22 75 m 0 - 10

Ten percent fines value > 50 kN 9.3.2 Aggregates for bituminous materials

(a) Coarse aggregate for bituminous materials shall be crushed rock all retained on a 5 mm BS test sieve and shall have the properties stated in Table 9.3.

(b) Fine aggregate for bituminous materials shall be crushed rock, river sand or a mixture

of crushed rock and river sand all passing 5 mm BS test sieve. The water absorption of fine aggregate shall not exceed 2.0%.

(c) For the purpose of mix design, the combined grading of aggregates for bituminous

materials shall be such that the particle size distribution lies within the limits stated in Table 9.4 for the relevant bituminous material.


Table 9.3: Properties of Coarse Aggregate for Bituminous Materials

Nominal maximum aggregate size (mm)

Properties

37.5 28 20 10

Flakiness index

25.0% 26.0% 27.0% 30.0%

Ten percent fines value > 100 kN Water absorption 2.0%

Table 9.4: Design Limits for Particle Size Distribution and Bitumen Content for Bituminous Materials

Type of bituminous material

Properties Roadbase (recipe mix)

Base course Wearing course Friction course

Nominal maximum aggregate size (mm)

37.5 37.5 28 20 10 10

BS test sieve


50mm 100 100 - - - - 37.5mm 90-100 91-100 100 - - - 28mm 70 - 94 70 - 94 91-100 100 - - 20mm 62 - 84 62 - 84 85 - 95 91-100 - - 14mm - 55 - 76 72 - 87 78 - 90 100 100 10mm 49 - 67 49 - 67 55 - 75 68 - 84 87-100 85-100 5mm 37 - 55 37 - 55 35 - 53 54 - 72 62 - 80 20 - 40 2.36mm 27 - 43 27 - 43 25 - 40 42 - 58 42 - 58 5 - 15 1.18mm - 20 - 35 15 - 30 34 - 48 34 - 48 - 600m 13 - 28 13 - 28 12 - 24 24 - 38 24 - 38 - 300m 7 - 21 7 - 21 8 - 18 16 - 28 16 - 28 - 150m - 4 - 14 5 - 12 8 - 18 8 - 18 -

Particle size distribution

75m 2 - 8 2 - 8 3 - 6 4 - 8 4 - 8 2 - 6 min. 3.0 4.0 4.5 5.0 6.0 4.5 Bitumen

content as percentage of total mass including binder

max. 4.0 4.5 5.0 5.5 7.0 5.5

9.3.3 Filler for bituminous materials

(a) Filler for bituminous materials shall be crushed rock filler, OPC, PPFAC, PFA or hydrated lime. Filler shall be free-flowing and dry before addition to the bituminous mixture.


(b) Filler for bituminous friction course material shall contain hydrated lime; the amount of hydrated lime, expressed as a percentage by mass of the total aggregates, shall be at least 1.5%.

(c) OPC shall comply with BS 12. PPFAC shall comply with BS 6588. (d) PFA shall comply with BS 3892 : Part 1 except that the criterion for maximum water

requirement shall not apply. (e) Crushed rock filler and hydrated lime shall comply with ASTM D 242.

9.3.4 Bitumen

Bitumen for bituminous materials shall comply with ASTM D 946, Grade 60-70 and shall have a softening point exceeding 44C and less than 55C. Blending or mixing of bitumen shall be carried out at a refinery reviewed without objection by the Project Manager.

9.3.5 Bituminous emulsion

Bituminous emulsion shall be anionic bituminous emulsion complying with BS 434 : Part 1, Table 1, Class A1-40 or cationic bituminous emulsion complying with BS 434 : Part 1, Table 2, Class K1-40.

9.3.6 Bituminous priming material

Bituminous priming material shall be medium curing-grade cutback bitumen complying with ASTM D 2027, Table 1, Class MC-30.

9.3.7 Handling and storage of sub-base material and bituminous materials

(a) Cement and PFA shall be stored as stated in Clause 20.33. (b) Sub-base material and bituminous materials shall not be handled or stored in a manner

which will result in mixing of the different types and sizes or in segregation or contamination of the materials.

(c) Bituminous materials shall not be stored in heated surge bins for more than 12 hours or

in transport vehicles for more than 3 hours. (d) Bituminous friction course material shall not be stored in surge bins for more than 30

minutes.

9.3.8 Transport of sub-base material and bituminous materials

(a) Sub-base material and bituminous materials shall be protected by covers while being transported and before laying. Covers for bituminous materials shall be heavy canvas or a similar insulating material; the covers shall completely cover the material and shall be securely fixed to minimise loss of heat and to protect the materials from contamination by dust or other deleterious material.

(b) Sub-base material and bituminous materials shall be transported in clean vehicles with

smooth trays and sides.


(c) The trays of vehicles transporting bituminous materials may be lubricated with soap solution or light oil sprayed on the trays. Vehicles transporting bituminous friction course material shall not be lubricated with light oil.

9.4 SUBMISSIONS 9.4.1 Particulars of filler and bitumen for bituminous materials

(a) The following particulars of the proposed filler and bitumen for bituminous materials shall be submitted to the Project Manager for review:

(i) a certificate from the manufacturer for each type of filler showing the

manufacturer's name, the date and place of manufacture and showing that the filler complies with the Specification and including results of tests for particle size distribution; and

(ii) a certificate from the manufacturer for bitumen showing the manufacturer's

name, the date and place of manufacture and showing that the bitumen complies with the Specification, including a temperature-viscosity relationship for the bitumen, and including results of tests for:

- relative density; - softening point; - penetration; - ductility; - retained penetration after thin film oven test; - solubility; - viscosity; and - loss on heating.

(b) Further certificates showing that the materials comply with the Specification shall be

submitted at intervals reviewed without objection by the Project Manager. 9.4.2 Particulars of mixes for sub-base material and bituminous materials

(a) The following particulars of sub-base material and bituminous roadbase materials shall be submitted to the Project Manager for review:

(i) source and type of aggregates;

(ii) grading details in tabular and graphical form; and

(iii) details of each mixing plant proposed.

(b) The following particulars of bituminous materials shall be submitted to the Project

Manager for review:

(i) certified copies of work sheets for mix designs, which shall include the relative density of the mixed aggregates;

(ii) source of bitumen; and

(iii) past test records of the same mix produced in the same plant.


9.4.3 Particulars of supplier of sub-base material and bituminous materials

The name of the supplier and the location of each plant from which the Contractor proposes to obtain sub-base material and bituminous materials shall be submitted to the Project Manager for review, together with a certificate of origin and certificate of quality.

9.4.4 Particulars of methods of laying and compacting sub-bases and bituminous materials

(a) The following particulars of the proposed methods of laying and compacting sub-bases and bituminous materials shall be submitted to the Project Manager for review:

(i) details of Contractor's Equipment; and

(ii) programme and rate of working.

9.4.5 Representative samples of sub-base material, aggregate, filler and bitumen

One representative sample of each type of sub-base material, and one representative sample of each type of aggregate, filler and bitumen for bituminous material of each proposed suppliers shall be submitted to the Project Manager at the same time as particulars are submitted.

9.5 WORKMANSHIP 9.5.1 Mixing of sub-base material and bituminous materials

Mixing of sub-base material and mixing of bituminous materials shall be carried out before delivery to Site at mixing plants reviewed without objection by the Project Manager. The plants shall be designed and operated to produce uniform mixes which comply with the specified requirements.

9.5.2 Mixing plant for bituminous materials

(a) The mixing plant for bituminous materials shall have at least four separate cold feed bins for preliminary cold batching of the coarse and fine aggregates, and a rotary drum dryer which will continuously agitate the aggregates during the heating and drying processes. After passing through the dryer, the aggregates shall be screened into at least four hot storage bins before mixing.

(b) Bitumen heating and storage tanks shall be fitted with circulating pumps to ensure an

even temperature throughout the tanks. (c) The mixing plant shall be provided with sampling devices to enable samples of hot

aggregates, filler and bitumen to be taken before mixing. (d) Insulated surge bins, if fitted to the mixing plant, shall be designed and operated to

prevent segregation occurring in the mix. Heating devices fitted to surge bins shall be capable of maintaining the temperature of the mix to within the specified limits.

(e) Measuring and weighing equipment shall be maintained in a clean, serviceable

condition. The equipment shall be set to zero daily and calibrated before mixes for the Permanent Works are produced, and at regular intervals not exceeding 6 months.


9.5.3 Mixing bituminous materials

(a) Aggregates and filler for bituminous materials shall be measured to an accuracy of ±3.0% by mass. The aggregate moisture content after drying shall not exceed 0.4% by mass.

(b) Mixing of bituminous materials shall continue after the addition of all constituents for

such period as is necessary to ensure that the aggregates and filler are uniformly coated with bitumen.

(c) Bituminous materials shall comply with the temperature requirements as stated in

Table 9.5 during and after mixing.

Table 9.5: Temperature Requirements for Bituminous Materials

Type of bituminous material

Roadbase, base course

and wearing course

Friction course

Aggregate temperature at mixing ( C) Min. 130 115 Max. 175 135 Binder temperature at mixing ( C) Min. 135 115 Max. 165 165 Bituminous mixture temperature Min. 130 115 after mixing ( C) Max 165 135 Bituminous mixture temperature Min. - 110 at laying ( C) Max. - 135 Bituminous mixture temperature Min. - 85 at start of compaction ( C)

9.5.4 Installation of utilities

(a) Pipes, cables, manholes, chambers, gullies and other utilities below carriageways shall be completed and fill material shall be deposited and compacted in trenches before the carriageway is constructed. Openings to manholes, chambers and gullies shall be protected by temporary covers.

(b) Covers, frames and other hardware which will prevent continuous laying of

bituminous materials for roadbase and base course shall not be fixed in position until such work is complete.

(c) After the penultimate layer of bituminous material has been laid and compacted, the

layers of asphalt shall be cut out, temporary covers shall be removed and the permanent covers, frames and other hardware shall be installed.

(d) Finishing around covers, frames and other hardware shall be carried out using

bituminous material of the same type as that in the adjacent surface. The material shall be compacted in layers not exceeding 50 mm thick using handrammers or mechanical equipment up to the underside of the wearing course or friction course.


9.5.5 Laying and compaction of sub-base material

(a) Sub-base material shall be laid and compacted in a manner which will not result in segregation of the material and at a moisture content which allows the compaction stated in Clause 9.5.5(f) to be achieved. The moisture content shall not be less than 2%.

(b) Sub-base material shall be laid in layers and compacted. The thickness of each

compacted layer shall not exceed 225mm. The minimum thickness of each layer shall be 100mm and, if the layers are of unequal thickness, the lowest layer shall be the thickest.

(c) Each layer of sub-base material shall be evenly spread immediately after placing in

position and shall be compacted immediately after spreading. (d) The minimum compaction plant to be used for compaction of sub-base material shall

be of the type as stated in Clause 9.5.9(a). (e) The Project Manager shall be notified before the next layer is placed on each layer of

compacted sub-base material. (f) Sub-base material shall be compacted to obtain a relative compaction of at least 95%

maximum dry density throughout. (g) The surface of each layer of sub-base shall be maintained in a compacted condition

until the next layer of sub-base material or roadbase material is laid; the surface shall not be disturbed by Contractor's Equipment or other vehicles, and shall be free from ridges, cracks, loose material, pot-holes, ruts or other defects.

9.5.6 Laying and compaction of bituminous materials

(a) Bituminous materials shall not be laid during periods of wet weather or when ponded water is present on the underlying surface.

(b) Bituminous wearing course material shall not be laid when the ambient air temperature

is below 8C and bituminous friction course material shall not be laid when the ambient air temperature is below 10C. Temperatures shall be measured in the shade near to the surface on which laying is to be carried out.

(c) Surfaces on which bituminous materials are laid shall be clean and free from mud, grit

and other deleterious material. (d) A tack coat of bituminous emulsion shall be applied to surfaces on or against which

bituminous materials will be laid. The tack coat shall be evenly applied at a rate of between 0.4 L/m² and 0.6 L/m² using a spray machine complying with BS 434 : Part 2. Bituminous materials shall not be laid until the tack coat has cured. Contractor's Equipment and other vehicles shall only run on the tack coat as necessary to lay the bituminous materials.

(e) If permitted by the Project Manager, surfaces of existing carriageways may be

regulated before the overlying bituminous material is laid; bituminous regulating course material shall be a material reviewed without objection by the Project Manager complying with the requirements for the 10 mm nominal maximum aggregate size wearing course material as specified in Table 9.3. Regulating course material shall be laid by paving machines.


(f) Bituminous materials shall comply with the temperature requirements as stated in Table 9.5 during laying and compaction.

(g) Where paved hard shoulders are provided, friction course shall be left proud of the

immediate underlying layer and in line with the front edge of the gully gratings or drainage channel, provided the friction course extends more than 0.5 m beyond the lane edge.

9.5.7 Laying bituminous materials by paving machine

(a) Bituminous materials shall be placed and spread using a self-propelled paving machine with a screw auger and attached screed capable of spreading and laying the material to the full width required. The paving machine shall be capable of giving initial compaction to the material and finishing it to a level suitable for subsequent compaction.

(b) Paving machines may be fitted with cut-off shoes or extensions to limit or extend the

width of the screed; screed extensions shall not be used unless the screw auger is extended in accordance with the manufacturer's recommendations. The surface texture produced by paving machines shall be free from segregation and from pushing or dragging marks.

(c) Bituminous materials laid by paving machines shall be placed directly from the

vehicles transporting the material into the hopper of the paving machine. Delivery of materials to the paving machine and laying of the materials shall be at a uniform rate appropriate to the capacity of the paving machine and compaction plant.

(d) If any delay in laying operations occurs, the paving machine shall be removed, the

uncompacted cold material shall be removed and a transverse joint shall be formed as stated in Clause 9.5.10.

(e) Paving machines working in echelon shall be as close as practicable; the machines

shall be not more than 30 m apart unless a longitudinal joint is formed as stated in Clause 9.5.10.

(f) Manual placing of materials on freshly laid surfaces shall only be used for the purpose

of locally correcting levels as paving operations proceed, before compaction by rolling is commenced.

9.5.8 Laying bituminous materials by manual methods

Bituminous materials shall be laid by manual methods only if in the opinion of the Project Manager the use of a paving machine is impracticable. If permitted by the Project Manager, bituminous materials may be laid by manual methods:

(a) in courses of irregular shape and varying thickness;

(b) in confined locations;

(c) adjacent to expansion joints, covers, frames and other hardware; and

(d) in reinstatements to trenches.


9.5.9 Compaction of bituminous materials and sub-base material

(a) The minimum compaction plant to be used to compact bituminous roadbase, base course, regulating course, wearing course and sub-base material shall be:

(i) a smooth three-wheeled steel-wheeled roller with a mass of between 6 t and 12 t, or a vibratory tandem steel-wheeled roller with an effective mass of between 6 t and 12 t, and a smooth pneumatic tyred-roller with a mass of between 12 t and 25 t, and with not less than seven overlapping wheels which have tyres that are capable of having pressures varying between 300 MPa and 800 MPa, and suitable mechanical rammers and hand-tools; or

(ii) other types of rollers, vibrating plates and rammers reviewed without objection

by the Project Manager, or other similar plant reviewed without objection by the Project Manager, necessary to produce the required degree of compaction.

(b) Bituminous roadbase, base course, regulating course and wearing course materials

shall be initially rolled using a steel-wheeled roller operated in a longitudinal direction along the carriageway with the driving wheels nearest the paving machine.

(c) All roller marks shall be removed from the surface of bituminous roadbase, base

course and wearing course materials using either a smooth-wheeled dead-weight roller or a smooth-wheeled vibratory roller in non-vibrating mode.

(d) Bituminous friction course material shall be compacted using rollers as stated in

Clause 9.5.9(a)(i) without the application of vibration; rollers shall not have an excessive film of water over the front and rear wheels. Bituminous friction course material shall be compacted until all roller marks are removed and the required degree of compaction is achieved.

(e) Rollers shall not be parked on newly laid or compacted bituminous materials. (f) Bituminous materials immediately adjacent to kerbs, covers, frames and other

hardware where rollers cannot operate effectively shall be compacted using hand-operated mechanical compaction plant.

9.5.10 Joints in bituminous materials

(a) The screed of the paving machine shall overlap previously laid strips of bituminous material by at least 50 mm and shall be sufficiently high that compaction will produce a smooth dense flush joint. Bituminous materials overlapping the previously laid strip shall be pushed back to the edge of the previously laid strip and the excess material shall be removed.

(b) Longitudinal joints in friction course or wearing course shall be formed coincident

with the specified position of the lane-markings. (c) A prepared joint shall be formed between hot bituminous material and cold material or

existing bituminous material which is at a temperature below the minimum specified laying temperature.

(d) The distance between prepared longitudinal joints in different layers shall be at least

150 mm and the distance between prepared transverse joints in different layers shall be at least 500 mm.


(e) Prepared joints in base course and wearing course shall be formed by cutting back the face of the cold material or existing bituminous material for a minimum distance of twice the depth of the layer or 100 mm, whichever is greater; a vertical face shall be cut for the full depth of the layer. All loosened materials shall be removed and the face shall be coated with bituminous emulsion; the bituminous emulsion shall not be applied beyond the edges of the joint. The hot bituminous materials shall be laid and compacted against the coated face with a joint formed as stated in this sub-section.

(f) Friction course joints shall not be coated with bituminous emulsion.

9.5.11 Protection of surfaces of sub-base material and bituminous materials

(a) The surface of each layer of sub-base material and bituminous materials shall be kept clean and free from deleterious material. Bituminous priming coat shall be applied to the final surface of the sub-base layer at a rate of between 0.9 L/m² and 1.1 L/m².

(b) Layers of carriageways under construction shall not be used by Contractor's

Equipment or vehicles other than those which are essential to construct the work. (c) Bituminous courses shall not be used by Contractor's Equipment or other vehicles until

6 hours after the material has been laid and compacted. 9.5.12 Tolerances: alignment of carriageway

The line of the edges of carriageways shall be within 25 mm of the specified line, except at the edges of structures where it shall be within 6 mm.

9.5.13 Tolerances: level of carriageway

(a) The levels of the surface of each layer of sub-base, roadbase, base course, wearing course and friction course shall be determined on a grid at 10 m centres in the longitudinal direction and at 2 m centres in the transverse direction.

(b) The level of the surface of each layer of sub-base, roadbase, base course, wearing

course and friction course shall be within the tolerances stated in Table 9.6. (c) The difference in level of the surface of wearing course and friction course across

joints shall not exceed 3 mm. (d) The combination of permitted tolerances in levels shall not result in a reduction in the

thickness of the pavement, excluding the sub-base, of more than 15 mm from the specified thickness nor a reduction in the thickness of the bituminous wearing course or friction course of more than 5 mm from the specified thickness.

Table 9.6: Tolerances in Level

Type of surface Permitted tolerance in level (mm)

Sub-base + 10 - 20

Roadbase course + 8 - 15

Base course

Wearing course ± 6

Friction course


9.5.14 Tolerances: covers, frames and other hardware

The level of covers, frames and other hardware shall be not lower than, and shall not be more than 5 mm higher than the surface of the carriageway. The level of gully gratings shall not be higher than, and shall not be more than 5 mm lower than, the surface of the carriageway.

9.6 INSPECTION, TESTING AND COMMISSIONING 9.6.1 Trial areas

(a) The Contractor shall produce trial areas of each type and layer of bituminous materials to demonstrate that the proposed materials, mixes, methods of production and methods of construction are capable of producing a carriageway which complies with the specified requirements. Unless otherwise stated in the Contract, the trial areas shall be constructed as part of the Permanent Works at locations reviewed without objection by the Project Manager. The width of each trial area shall be at least one lane of carriageway, and the length shall be at least 60 m.

(b) Trial areas shall be constructed using the materials, mixes, methods of production and

methods of construction submitted to and reviewed without objection by the Project Manager. Materials shall be delivered in not less than two loads.

(c) The Contractor shall notify the Project Manager 48 hours before constructing trial

areas. (d) The Contractor shall notify the Project Manager before each layer of material is placed

in the trial area. (e) The Contractor shall not proceed placing materials of the same type in the permanent

carriageway until he obtains a notice of no objection from the Project Manager.

Table 9.7: Sampling and Testing Bituminous Materials

Type of material Properties Methods of sampling

Methods of testing

Bituminous base course and wearing course material

Particle size distribution Bitumen content Rice's specific gravity Void content

Clause 9.6.13(b) Clause 9.6.13(b) Clause 9.6.13(b) Clause 9.6.15(a)

Clause 9.6.13(c) Clause 9.6.13(c) Clause 9.6.13(c) Clause 9.6.15(b)

Bituminous friction course material

Particle size distribution Bitumen content Texture depth and permeability

Clause 9.6.14(b) Clause 9.6.14(b)

-

Clause 9.6.14(a) Clause 9.6.14(a) Clause 9.6.16(a)

9.6.2 Samples: trial areas

(a) One sample of bituminous materials, excluding bituminous roadbase materials, shall be provided from each mix used in trial areas. The method of sampling shall be as stated in Table 9.7

(b) Ten cores shall be cut from each layer of base course and wearing course in trial areas.

The method of taking cores shall be as stated in Clause 9.6.15 (a).


9.6.3 Testing: trial areas

(a) Each sample of bituminous material taken as stated in Clause 9.6.2, shall be tested to determine the properties stated in Table 9.5. The method of testing shall be as stated in Table 9.5.

(b) If the layer is to form part of the Permanent Works, each layer of bituminous material

in trial areas, excluding bituminous roadbase material, shall be tested as stated in Clause 9.5.13 to determine the level of the surface.

(c) The layer which is to be the final layer of the carriageway in each trial area shall be

tested as stated in Clauses 9.6.9 (a) and 9.6.9 (b) to determine the surface regularity, if the layer is to form part of the Permanent Works.

(d) The layer of friction course in each trial area shall be tested as stated in Clauses 9.6.16

(a) to 9.6.16 (c) to determine the texture depth and permeability. (e) Cores shall be tested as stated in Clauses 9.6.15 (a) to 9.6.15 (d) to determine the

compacted layer thickness and air void content. 9.6.4 Compliance criteria: trial areas

The properties of the materials, the levels of the surface, compaction, surface regularity, texture depth and permeability of bituminous materials laid in the trial areas shall comply with the specified requirements for the permanent carriageway.

9.6.5 Non-compliance: trial areas

(a) If the result of any test on trial areas does not comply with the specified requirements for trial areas, particulars of proposed changes to the materials, mixes, methods of production or methods of construction shall be submitted to the Project Manager for review and further trial areas shall be constructed until the result of every test on trial areas complies with the specified requirements for the trial areas.

(b) Trial areas, or parts of trial areas, which do not comply with the specified requirements

for the trial area shall be removed. 9.6.6 Acceptable mix for bituminous materials other than bituminous roadbase material

(a) A mix for bituminous materials other than bituminous roadbase material which complies with the specified requirements for designed mixes and for trial areas is defined as an "Acceptable Mix".

(b) The "Acceptable Gradation Envelope" for bituminous materials other than bituminous

roadbase material is defined as the gradation envelope found by applying the tolerances stated in Table 9.8 to the particle size distribution of the "Acceptable Mix".

(c) The "Acceptable Bitumen Content Range" for bituminous materials other than

bituminous roadbase material is defined as the bitumen content range formed by applying a tolerance of ±0.5% to the bitumen content of the "Acceptable Mix".


Table 9.8: Tolerances for Particle Size Distribution from Acceptable Mix

Tolerance of particle size distribution in percentage By mass of total mix passing BS test sieve

BS test sieve Nominal maximum aggregate size (mm) 37.5 28 20 10

50 mm 0 - - - 37.5 mm ± 4 0 - - 28 mm ± 7 ± 4 0 - 20 mm ± 7 ± 7 ± 4 - 14 mm ± 7 ± 7 ± 7 0 10 mm ± 7 ± 7 ± 7 ± 4 5 mm ± 7 ± 7 ± 7 ± 7 2.36 mm ± 7 ± 7 ± 7 ± 7 1.18 mm ± 7 ± 7 ± 7 ± 7 600 m ± 5 ± 5 ± 5 ± 5 300 m ± 5 ± 5 ± 5 ± 5 150 m ± 3 ± 3 ± 3 ± 3 75 m ± 2 ± 2 ± 2 ± 2

9.6.7 Commencement of placing bituminous materials

Bituminous material shall not be placed in the Permanent Works until the mix has been reviewed without objection by the Project Manager.

9.6.8 Changes in materials and methods of construction

The materials and methods of production used in producing the mixes and the methods of construction used in trial areas shall not be changed after having been reviewed without objection by the Project Manager.

9.6.9 Testing: surface regularity

(a) Testing method

The surface regularity of the final layer of the pavement shall be determined as stated in Clause 10.5.8(a).

(b) Compliance criteria: surface regularity

The results of tests for surface regularity shall comply with Clause 10.5.8(b)

9.6.10 Testing : Sub-Base Material

(a) Batch: sub-base material

A batch of sub-base material is a quantity not exceeding 250 m³ of sub-base material of the same type and same mix produced at the same mixing plant, and delivered to Site at any one time.

(b) Samples: sub-base material

(i) One sample of each type of sub-base material shall be provided from each batch

of sub-base material delivered to Site.


(ii) The size of each sample shall be at least 50 kg. The method of sampling shall be in accordance with BS 812 : Part 102.

(c) Testing: sub-base material

(i) Each sample of sub-base material shall be tested to determine the particle size

distribution, ten percent fines value, maximum dry density, optimum moisture content and plasticity index of the portion passing a 425m BS test sieve.

(ii) The method of testing for particle size distribution shall be in accordance with

BS 812:Part 103.1.

(iii) The method of testing for ten percent fines value shall be in accordance with BS 812:Part 111, except that the sample shall be soaked in water at room temperature for 24 hours and shall not be oven-dried before testing.

(iv) The method of testing for plasticity index shall be in accordance with GEO

Report No. 36, Tests 2.4.3 and 2.5.3, except that sample preparation shall be by wet sieving the material over a 425 m BS test sieve.

(v) The method of testing for maximum dry density and optimum moisture content

shall be in accordance with BS 1377 : 1975, Test 13, and Appendix 7.5 of this General Materials and Workmanship Specification.

9.6.11 Testing : Relative Compaction Of Sub-Base

(a) Testing methodology

(i) Each area of sub-base which contains sub-base material of the same type and same mix produced at the same mixing plant and which is laid and compacted in a single layer in one day shall be tested to determine the relative compaction. Tests shall be carried out after the sub-base material has been laid and compacted in the final position.

(ii) Two tests shall be carried out on each area of 1000 m² or part thereof laid and

compacted each day.

(iii) Tests shall be carried out at positions which are representative of the area of compacted sub-base as a whole.

(iv) The method of testing for relative compaction shall be as stated in Clause

7.6.17(d) Method 1 for fill material, except that the determination of maximum dry density shall be in accordance with Clause 9.6.10(c)(v), and the in-situ density in accordance with Clause 7.6.17(e).

(b) Compliance criteria: relative compaction of sub-base

The results of tests for relative compaction of sub-base shall comply with the requirements stated in Clause 9.5.5(f).

(c) Non-compliance: relative compaction of sub-base

If the result of any test for relative compaction of sub-base does not comply with the specified requirements for relative compaction of sub-base, the area shall be re-compacted and two additional tests for relative compaction of sub-base shall be carried out on the area.


9.6.12 Testing : Aggregates, Filler And Bitumen For Bituminous Materials

(a) Batch: aggregates, filler and bitumen for bituminous materials

A batch of aggregate, filler or bitumen for bituminous materials is any quantity of aggregate, filler or bitumen for bituminous materials of the same type, manufactured or produced in the same place and covered by the same certificates delivered to Site at any one time.

(b) Samples: aggregates, filler and bitumen for bituminous materials

(i) One sample of each type of aggregate, filler and bitumen for bituminous

materials shall be provided from each batch.

(ii) The size of each sample and the method of sampling shall be as stated in Table 9.9.

Table 9.9: Size of Samples and Method of Sampling for Aggregates, Filler and Bitumen

Material Minimum size

of sample Method of sampling

Aggregate, nominal maximum aggregate size exceeding 28 mm

50 kg

Aggregate, nominal maximum aggregate size 5 mm to 28 mm

25 kg

Aggregate, nominal maximum aggregate size less than 5 mm

10 kg

BS 812:Part 102

Filler 5 kg ASTM D 242

Bitumen 2 litres ASTM D 140

(c) Testing: aggregates, filler and bitumen for bituminous materials

Each sample of aggregate, filler and bitumen for bituminous materials shall be tested to determine the properties stated in Table 9.10. The method of testing shall be as stated in Table 9.10.

Table 9.10: Testing Aggregates, Filler and Bitumen for Bituminous Materials

Material Property Method of testing

Coarse aggregate Relative density

Water absorption

BS 812 : Part 2

Ten percent fines value BS 812 : Part 111

Particle size distribution BS 812 : Part 103.1

Flakiness index BS 812 : Part 105

Fine aggregate Relative density

Water absorption

BS 812 : Part 2

Particle size distribution GEO Report No. 36, test 2.9.2B


Material Property Method of testing

Filler Relative density BS 4550 : Part 3

Particle size distribution BS 812 : Part 103.1

Bitumen Relative density ASTM D 3289

Softening point BS 2000

Penetration ASTM D 5

Ductility ASTM D 113

Retained penetration after thin film oven test

ASTM D 1754

Solubility ASTM D 2042

Viscosity ASTM D 2171 or BS 2000

Loss on heating BS 2000

9.6.13 Testing : Bituminous Materials Other Than Bituminous Friction Course Material

(a) Batch: bituminous materials other than bituminous friction course material

A batch of bituminous materials other than bituminous friction coarse material is a quantity not exceeding the limits stated in Table 9.11 of bituminous materials of the same type and same mix produced at the same mixing plant in one day.

Table 9.11: Maximum Size of Batch for Bituminous Materials other than Bituminous

Friction Course Material

Material Maximum batch size (t)

Wearing course 100

Base course 150

Road base 200

(b) Samples: bituminous materials other than bituminous friction course material

(i) One sample of bituminous material other than bituminous friction course material shall be provided from each batch unless otherwise required by the Project Manager.

(ii) The size of each sample shall be as stated in Table 9.12.

(iii) Samples shall be taken at the mixing plant or at the location where the

bituminous material will be laid as directed by the Project Manager. Samples taken at the mixing plant shall be taken from the delivery vehicle immediately after loading from the plant or from the surge bin. Samples taken at the location where the bituminous materials will be laid shall be taken from the delivery vehicle.

(iv) The method of sampling shall be in accordance with ASTM D 979.


Table 9.12: Size of Samples for Bituminous Materials other than Bituminous Friction Course Material

Material Minimum size of sample (kg)

Wearing course

(10mm nominal maximum aggregate size)

10

Wearing course

(20mm nominal maximum aggregate size)

16

Base course 24

Roadbase 24

(c) Testing: bituminous materials other than bituminous friction course material

(i) Each sample of bituminous materials taken as stated in Clause 9.6.13(b) (i) shall

be tested to determine the particle size distribution, bitumen content and Rice's specific gravity.


Particle size distribution : ASTM C 136 with modifications and

ASTM C 117, Method B Bitumen content : ASTM D 2172, Method A Rice's specific gravity : ASTM D 2041, Weighting-in-water method Bulk specific gravity : ASTM D 2726

(iii) For particle size distribution tests in accordance with ASTM C 136, the

modifications are:

Sieves to BS410 instead of sieves to ASTM E11 shall be used. Each sample of bituminous materials taken as stated in Clause 9.6.13(b) shall be reduced to test specimen of suitable size as follows:

Nominal Maximum Minimum Sample Size (kg) Aggregate Size (mm)

37.5 2.5 28.0 2.0 20.0 1.5 10.0 1.0

(iv) The residual pressure manometer specified in ASTM D 2041 shall be replaced

by a vacuum gauge.


(d) Compliance criteria : bituminous materials other than bituminous friction course material The results of tests on bituminous materials other than bituminous friction course material shall comply with the following requirements:

(i) The particle size distribution shall be such that not more than two points on the

particle size distribution curve are outside the "Acceptable Gradation Envelopes" determined as stated in Clause 9.6.6(b). The percentage passing the 75 m BS test sieve shall not exceed the acceptable design value by more than 3%.

(ii) The bitumen content shall be within the "Acceptable Bitumen Content Range"

determined as stated in Clause 9.6.6(c). 9.6.14 Testing : Bituminous Friction Course Material

(a) Batch: bituminous friction course material

A batch of bituminous friction course material is a quantity not exceeding 100 t of bituminous friction course material of the same mix produced at the same mixing plant in one day.

(b) Samples: bituminous friction course material

(i) One sample of bituminous friction course material shall be provided from each

batch of bituminous friction course material.

(ii) The size of each sample shall be at least 15 kg.

(iii) Samples shall be taken at the mixing plant from the delivery vehicle immediately after loading from the plant or from the surge bin.

(iv) The method of sampling shall be in accordance with ASTM D 979.

(c) Testing: bituminous friction course material

(i) Each sample of bituminous friction course material shall be tested to determine

the particle size distribution and bitumen content.


Particle size distribution : ASTM C 136 with modifications and ASTM C 117, Method B Bitumen content : ASTM D 2172, Method A

(iii) For particle size distribution tests in accordance with ASTM C 136, the

modifications are:

Sieves to BS410 instead of sieves to ASTM E11 shall be used.


Each sample of bituminous materials taken as stated in Clause 9.6.14(b) shall be reduced to test specimen of suitable size as follows:

Nominal Maximum Minimum Sample Size (kg) Aggregate Size (mm)

37.5 2.5 28.0 2.0 20.0 1.5 10.0 1.0

(d) Compliance criteria: bituminous friction course material

The results of tests on bituminous friction course material shall comply with the following requirements:

(i) The particle size distribution shall be within the "Acceptable Gradation

Envelopes" as determined in Clause 9.6.6(b).

(ii) The bitumen content shall be within the "Acceptable Bitumen Content Range" as determined in Clause 9.6.6(c).

9.6.15 Testing : Bituminous Material Cores

(a) Samples: bituminous material cores

(i) Each area of roadbase, base course and wearing course which contains bituminous material of the same type and same mix produced at the same mixing plant and which is laid and compacted in a single layer in one day shall be tested to determine the compacted layer thickness.

(ii) Each area of bituminous material to be tested shall be divided into

approximately equal sub-areas as stated in Table 9.13. One core shall be taken at random from each sub-area.

(iii) Cores shall not be taken from within 300 mm of covers, frames and other

hardware, or construction joints in the bituminous material.

(iv) Cores shall be taken by a mechanically operated coring machine.

(v) Cores shall be 150 mm diameter for bituminous material with a designed layer thickness of 40 mm or greater and shall be 100 mm diameter for bituminous material with a designed layer thickness of less than 40 mm.

(vi) Cores shall be taken as soon as practicable but not later than 48 hours after

completion of the paving operation.

(vii) If permitted by the Project Manager, the sampling rate for roadbase may be applied to wearing course and base course.

(viii) Holes formed by taking cores shall be filled with compatible bituminous

material as soon as practicable after the core has been taken.


Table 9.13: Rate of Sampling for Bituminous Material Cores

No. of sub-areas/cores Area of bituminous material

laid and compacted in one day Roadbase Wearing course and Base course

< 5 000 m² 4 10

5 000 - 10 000 m² 10 15

> 10 000 m² 20 20

(b) Testing: bituminous material cores

(i) Each bituminous material core shall be measured to determine the compacted layer thickness of the bituminous material and tested to determine the air void content.

(ii) The method of testing for air void content shall be in accordance with ASTM D

3203.

(c) Compliance criteria: bituminous material cores

The results of tests on bituminous material cores shall comply with the following requirements:

(i) The average air void content of the cores taken from an area of bituminous base

course or wearing course material shall be not less than 3.0% and not greater than 6.0%.

(ii) The air void content of each core taken from an area of bituminous base course

or wearing course material shall be not less than 2.5% and not greater than 7.5%.

(iii) The air void content of each core taken from an area of bituminous roadbase

material shall be not less than 3.0% and not greater than 9.0%.

(iv) The compacted layer thickness as measured from each core shall comply with the thickness requirements stated in Clause 9.5.13(d) and shall be compatible with the level tolerances stated in Table 9.6.

(d) Non-compliance: bituminous material cores

(i) If the result of any test for air void content of cores does not comply with the

specified requirements for air void content, the following procedure shall apply: - Four additional cores, shall be taken from each sub-area for which the

original core did not comply with the specified requirements for air void content. The cores shall be taken at locations evenly spaced throughout the sub-area such that they are representative of the sub-area as a whole.

- Each additional core shall be tested to determine the air void content and the test results of the additional cores from the same sub-area shall be averaged.

- The average air void content of the sub-area thus obtained shall replace the original air void content of the respective sub-area. The new average air void content of the area of bituminous material tested shall then be calculated for compliance checking.


(ii) If the air void content of any of the four additional cores determined as stated in Clause 9.6.15(b)(ii) is less than 2.5% or greater than 7.5% for bituminous base course material and bituminous wearing course material, or less than 3.0% or greater than 9.0% for bituminous roadbase material, the sub-area from which the cores were taken shall be considered as not complying with the specified requirements.

(iii) The area of bituminous material tested shall be considered as not complying

with the specified requirements for average air void content if the average air void content of the cores taken from the area does not comply with the specified requirements for average air void content.

(iv) If the result of any test for compacted layer thickness of cores is not compatible

with the requirements of Table 9.6 or Clause 9.5.13(d), four additional cores shall be taken from the same sub-area and the results averaged to determine the average compacted layer thickness. The cores shall be taken at locations evenly spaced throughout the sub-area such that they are representative of the sub-area as a whole.

(v) If the average compacted layer thickness determined as stated in Clause

9.6.15(d)(iv) is not in accordance with the permitted compacted layer thickness stated in Clause 9.6.15(c)(iv), the sub-area from which the cores were taken shall be considered as not complying with the specified requirements.

9.6.16 Testing : Texture Depth And Permeability

(a) Testing: texture depth and permeability

(i) Each area of friction course to be tested shall be divided into approximately equal sub-areas as stated in Table 9.14. Tests for texture depth and permeability shall be carried out on each sub-area at positions which are representative of the sub-area of friction course as a whole. No measurement shall be taken within 300 mm of the longitudinal edge of the carriageway.

(ii) If permitted by the Project Manager the number of tests for texture depth and

permeability may be reduced to the minimum stated in Table 9.14.

(iii) Tests shall be carried out before the area of friction course is used by Contractor's Equipment or other vehicles.

(iv) Testing to determine the texture depth will be carried out by the Contractor in

the presence of the Project Manager. The method of testing shall be by the sand patch test in accordance with Appendix 10.1.

(v) Testing to determine the permeability will be carried out by the Contractor in

the presence of the Project Manager. The method of testing shall be in accordance with Appendix A9.1.

(b) Compliance criteria: texture depth

The results of tests for texture depth on an area of course shall comply with the following requirements:

(i) the average texture depth shall not be less than 1.5 mm; and

(ii) not more than one of the tests for texture depth shall give a result of less than

1.2 mm.


(c) Compliance criteria: permeability

The time for 150 mL of water to drain into the friction course in the permeability test stated in Clause 9.6.16(a)(v) shall not exceed 30 seconds.

Table 9.14: Rate of Testing for Texture Depth and Permeability

No. of sub-areas/tests

Area of bituminous material laid and compacted in one day

Normal Minimum < 5 000 m² 10 4 5 000 – 10 000 m² 15 10 > 10 000 m² 20 20


APPENDIX A9.1

DETERMINATION OF THE PERMEABILITY OF FRICTION COURSE MATERIAL

A9.1.1 Scope This method covers the determination of the permeability of friction course material by

measuring the time taken for 150 mL of water to drain into the material. A9.1.2 Apparatus The following apparatus is required:

(1) a non-porous ring with an opening of internal diameter of 150 mm ± 2 mm, and a minimum height of 20 mm;

(2) suitable sealant for sealing one end of the ring onto the friction course surface;

(3) a measuring cylinder for measuring 150 mL of water to an accuracy of 1 mL;

(4) two containers, each suitable for containing and pouring 150 mL of water; and

(5) a stop watch.

A9.1.3 Procedure


(1) carefully inspect the specified test location and record any unusual features;

(2) place one end of the ring on the friction course at the location to be tested, and seal the interface with sealant to prevent any leakage of water;

(3) prepare two volumes of water of 150 mL each using the measuring cylinder and the

two containers;

(4) pour one 150 mL measure of water into the ring quickly and steadily without spillage;

(5) as soon as all of the water has drained into the friction course, pour the second 150 mL of water into the ring quickly and steadily without spillage, and at the same time start the stop watch;

(6) record the time taken for the second 150 mL of water to drain into the friction course

surface. A9.1.4 Reporting of results


(1) the test location; and

(2) the time taken for the second 150 mL of water to drain into the friction course surface, to the nearest one second.


SECTION 10 CONCRETE CARRIAGEWAYS

10.1 GENERAL 10.1.1 General requirements

The Permanent Works and materials specified shall comply with the Sections stated, unless otherwise stated in this Section. (a) Formwork and finishes to concrete for concrete carriageways shall comply with

Section 18. (b) Steel reinforcement for concrete carriageways shall comply with Section 19. (c) Concrete for concrete carriageways shall comply with Section 20. (d) Curing compound for concrete carriageways shall comply with Section 20. (e) Earthworks for concrete carriageways shall comply with Section 7.

10.2 MATERIALS 10.2.1 Reinforcement

(a) Fabric reinforcement shall be steel fabric complying with BS 4483; the fabric shall be manufactured from steel wire which complies with BS 4482 and which has a type 2 bond classification.

(b) Dowel bars, tie bars, cradles and tie bars for cradles shall be Grade 250 plain round

steel bars complying with CS2. Dowel bars and tie bars shall be straight; both ends of dowel bars and one end of tie bars shall be sawn square with all burrs removed.

10.2.2 Cement mortar for cradles

Cement mortar for supporting cradles shall consist of 1 part of cement to 3 parts of fine aggregate together with the minimum amount of water necessary to achieve a consistency suitable for the required work. Fine aggregates shall be sand or crushed rock to BS 1200 and shall pass a 5 mm BS test sieve.

10.2.3 Fine aggregate

Fine aggregate for concrete shall be natural river-deposited sand consisting of at least 95% by mass of quartz grains.

10.2.4 Polyethylene sheeting



10.2.5 Joint filler

Joint filler shall be a proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler.

10.2.6 Joint sealant

(a) Joint sealant shall be of a grade suited to the climatic conditions of Hong Kong and shall perform effectively over a temperature range of 0C to 60C.

(b) Joint sealant shall be a cold poured two-part polymer-based sealant complying with

BS 5212, Type N. (c) Primers and caulking material for use with joint sealant shall be proprietary types

recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager.

10.2.7 Bond breaker tape

Bond breaker tape shall be a proprietary type recommended by the joint sealant manufacturer and reviewed without objection by the Project Manager. The tape shall be a polyethylene film with adhesive applied on one side and shall be the full width of the groove.

10.2.8 Groove forming strip

(a) Groove forming strip shall be a proprietary type reviewed without objection by the Project Manager. The strip shall be a firm compressible strip of either ethylene vinyl acetate foam with a density of at least 90 kg/m³ or synthetic rubber. The strip shall be 25 mm deep and 5 mm thick and shall be sufficiently rigid to remain in position during concreting without deforming or stretching.

(b) Adhesive for groove forming strip shall be a proprietary type recommended by the

groove forming strip manufacturer and reviewed without objection by the Project Manager.

10.2.9 Sleeves for dowel bars and tie bars

Sleeves for dowel bars and tie bars shall be PVC and shall have a nominal wall thickness not exceeding 1.5 mm; the sleeves shall fit tightly to the bars.

10.2.10 Epoxy resin grout

Epoxy resin grout shall be a proprietary type reviewed without objection by the Project Manager.

10.2.11 Concrete mix

Concrete for concrete carriageways shall comply with the following requirements:

(a) concrete shall be Grade 40/20 and shall be a designed mix; (b) the concrete mix shall contain either PPFAC or a minimum of 265 kg of OPC plus a

minimum of 85 kg of PFA per m³ of compacted concrete;


(c) the percentage by mass of fine aggregate to total aggregate shall be at least 30%; and (d) the workability in terms of designed slump value shall not exceed 25 mm.

10.2.12 Cementitious content of concrete

The minimum cementitious content of concrete for concrete carriageways shall be 350 kg/m³.

10.3 SUBMISSIONS 10.3.1 Particulars of materials for joints

(a) The following particulars of the proposed materials for joints in concrete carriageways shall be submitted to the Project Manager:

(i) manufacturer's literature and a certificate for joint filler showing the

manufacturer's name, the date and place of manufacture and stating that the joint filler complies with the Specification, including results of tests for: - disintegration and shrinkage; - recovery value and reduction in mass; and - extrusion;

(ii) manufacturer's literature for joint sealant, including details of the method and

time required for mixing the different components, and a certificate showing the manufacturer's name, the date and place of manufacture and stating that the sealant complies with the Specification, including results of tests for: - application life; - tack-free time; - resistance to flow; - recovery; - adhesion and cohesion in tension and compression; and - resistance to heat ageing;

(iii) manufacturer's literature and a certificate for groove forming strip showing the

manufacturer's name, the date and place of manufacture and stating that the groove forming strip complies with the Specification, including results of tests for density; and

(iv) particulars of primers and caulking material for joint sealant, adhesive for

groove forming strip, bond breaker tape and sleeves for dowel bars and tie bars.

(b) The particulars, including certificates, shall be submitted to the Project Manager at least 14 days before the first delivery of the material to Site. Certificates shall be submitted for each batch of the material delivered to Site.

10.3.2 Particulars of methods of construction

Particulars of proposed methods of construction for concrete carriageways shall be submitted to the Project Manager at least 21 days for review before the trial length is constructed.


10.3.3 Representative samples of materials

Representative samples of the following proposed materials shall be submitted to the Project Manager at the same time as particulars of the material are submitted:

(a) polyethylene sheeting; (b) joint filler; (c) bond breaker tape; (d) groove forming strip; and (e) sleeves for dowel bars, including compressible filler, and for tie bars.

10.4 WORKMANSHIP 10.4.1 Installation of utilities

(a) Pipes, cables, manholes, chambers, gullies and other utilities below concrete carriageways shall be completed and fill material shall be deposited and compacted in trenches before the carriageway is constructed. Openings to manholes, chambers and gullies shall be protected by temporary covers.

(b) Box-outs shall be formed in concrete carriageways for covers, frames and other

hardware; the covers, frames and other hardware shall be fixed in position after the main slab has been concreted and before the infill slab is concreted.

10.4.2 Preparation of formation and sub-base

Construction of concrete carriageways shall start as soon as practicable after the formation or sub-base has been completed. The formation shall be protected as stated in Clause 7.4.33 and the sub-base shall be protected as stated in Clause 9.5.11 until construction of the carriageway starts.

10.4.3 Laying polyethylene sheeting

Polyethylene sheeting below concrete carriageways shall be laid flat without creases. Laps shall be at least 300 mm and there shall be no gaps at the edges of bays.

10.4.4 Formwork

(a) Formwork for concrete carriageways shall be steel. The finish to concrete surfaces for transverse and longitudinal joints shall be Class F3; the finish to concrete surfaces for other edges of the carriageway shall be Class F2.

(b) Concrete shall not be placed against excavated surfaces or against kerbs. (c) Formwork shall not be loosened or removed until at least 7 hours after concreting has

been completed.


10.4.5 Forming joints

(a) Materials for joints in concrete carriageways shall be used in accordance with the manufacturers' recommendations or as otherwise specified in the Specification.

(b) Dowel bars, tie bars and their sleeves shall be securely fixed in position through holes

in the formwork before concreting. The bars shall be parallel to the top surface of the slab and to each other. Bars at transverse joints shall be parallel to the adjacent longitudinal joint or to the longitudinal axis of the carriageway if there is no longitudinal joint or to other lines directed by the Project Manager.

(c) Joint filler shall be cut to size before fixing and shall be securely fixed in position to

the existing concrete surface before concreting. There shall be no gaps between the joint filler and the formation. Holes in joint filler for dowel bars shall be cut to form a sliding fit to the sleeved bar.

(d) Joints shall be formed perpendicular to the top surface of the slab.

10.4.6 Transverse joints

(a) Transverse joints in concrete carriageways shall be straight and perpendicular to the longitudinal axis of the carriageway.

(b) Transverse expansion joints and transverse contraction joints shall be formed only at

the specified positions. The joints shall be continued across longitudinal joints and shall be in line and of the same type on both sides of the longitudinal joint. The joints shall be continued through kerbs, edgings and quadrants and their foundation and backing; the joint dimensions and materials shall be the same as the transverse joints with the omission of dowel bars. The location of additional contraction joints in accordance with Clause 11.5.15(c) shall be as directed by the Project Manager.

(c) The joint filler and groove for joint sealant at transverse expansion joints shall provide

complete separation of adjacent slabs. 10.4.7 Longitudinal joints

Longitudinal joints in concrete carriageways shall be formed only at the specified positions. 10.4.8 Isolation joints

Isolation joints shall be formed in concrete carriageways at manholes and chambers. 10.4.9 Forming grooves

(a) Grooves in concrete carriageways for joint sealant shall be straight, shall have parallel sides and shall be perpendicular to the top surface of the slab. The bottom of the groove shall be flat and shall be parallel to the top surface of the slab.

(b) Grooves at transverse expansion joints and at isolation joints at manholes and

chambers shall be formed by sawing the groove to the specified width and depth not less than 7 days after concreting. The grooves shall be located over the joint filler such that the upper surface of the joint filler is entirely contained in the groove.


(c) Grooves at transverse contraction joints shall be formed using one of the following methods:

(i) Method 1 :

An initial groove shall be sawn as soon as practicable after concreting without causing spalling of the edges. The width of the initial groove shall be less than the specified width of the final groove and the depth of the initial groove shall be between 1/4 and 1/3 of the thickness of the slab. The final groove shall be sawn to the specified width and depth not less than 7 days after concreting; or

(ii) Method 2 :

The final groove shall be sawn to the specified width and depth as soon as practicable after concreting without causing spalling of the edges. The centre lines of the initial and final grooves shall coincide.

(d) Grooves at transverse construction joints shall be formed by fixing groove forming

strip with adhesive to the concrete already placed before concreting the adjacent slab. 10.4.10 Protection of grooves

Before permanent sealing, grooves in concrete carriageways for joint sealant shall be protected from contamination by a temporary sealing strip.

10.4.11 Sealing joints

(a) The permanent sealing of joints in concrete carriageways shall be carried out at least 7 days after concreting.

(b) Immediately before permanent sealing, groove forming strips, temporary seals, dirt

and loose material shall be removed from the groove and the sides of the groove shall be cleaned and roughened by water jetting or sand blasting.

(c) Caulking material shall be firmly packed in the bottom of the groove if the joint

sealant is not required to extend to the bottom of the groove. (d) Bond breaker tape shall be fixed continuously and evenly along the bottom of the

groove for the full width and length of the groove. (e) Primer for the joint sealant shall be applied to the sides of the groove in accordance

with the manufacturer's recommendations. (f) Joint sealant shall be applied between the minimum and maximum drying times of the

primer recommended by the manufacturer. The components of the sealant shall be thoroughly mixed in accordance with the manufacturer's recommendations using a power operated paddle mixer for sufficient time to produce a homogeneous mass without entrapped air. The sealant shall be dispensed into the groove as soon as practicable after mixing and within the time recommended by the manufacturer.

(g) The groove shall be clean and dry at the time of applying the primer and joint sealant. (h) Excess joint sealant shall be removed by using a purpose made finishing tool such

that the finished surface of the sealant is between 4 mm and 6 mm below the surface of the slab.


10.4.12 Placing and compacting concrete

(a) Concrete shall be placed continuously between the joints in concrete carriageways. (b) Concrete shall be compacted by internal vibrators to produce a dense homogenous

mass. The number and types of vibrators shall be sufficient to ensure full compaction of the concrete at the rate at which it is placed. Sufficient vibrators in serviceable condition shall be kept on Site so that spare equipment is always available in the event of breakdowns.

(c) Concrete in unreinforced slabs shall be placed and compacted to the full thickness of

the slab in one operation. (d) Unless otherwise permitted by the Project Manager, concrete in reinforced slabs shall

be placed and compacted to the specified level of the fabric reinforcement; the fabric reinforcement shall be placed in position and concrete shall be placed and compacted to the remaining thickness of the slab. The time between compaction of the first layer and placing of the remaining layer shall not exceed 30 minutes unless in the opinion of the Project Manager the concrete already placed is sufficiently workable and the permission of the Project Manager has been obtained. Otherwise a construction joint shall be formed as stated in Clause 20.7.14; concrete shall not be placed against the concrete already placed for at least 24 hours.

(e) Concrete in infill slabs at covers, frames and other hardware shall be placed and

compacted after the covers, frames and hardware have been fixed in position and shall not be placed at the same time as the concrete in the main slab.

10.4.13 Construction joints

(a) Construction joints shall be formed in concrete carriageways only where permitted by the Project Manager or in cases of emergency if concreting is interrupted by adverse weather, plant breakdown or similar circumstances. Construction joints shall not be formed within 2.5 m of an existing or planned expansion or contraction joint.

(b) Transverse construction joints shall be formed by either:

(i) using formwork and cast-in tie bars; or

(ii) breaking back from an unformed edge and fixing the tie bars and sleeves with

epoxy resin grout in drilled holes. 10.4.14 Surface regulation

(a) Unless combined double beam compactor-levellers are used, after compaction the concrete in concrete carriageways shall be struck off to slightly above the levels of the formwork and the surface shall be regulated by a regulating machine or a vibrating beam.

(b) Regulating machines shall be purpose made and shall span the full width of the slab

either transversely or obliquely. The machine shall be equipped with at least two oscillating-type transverse screeds and shall be supported on a carriage.

(c) Vibrating beams shall have a steel or aluminium surface and shall be mounted on a

separate carriage. The beam shall be driven by a motor to provide a vibration frequency of at least 3500 cycles per minute.


(d) After regulation by the regulating machine or vibrating beam, the surface of the carriageway shall be regulated by at least two passes of a scraping straight-edge with a blade length of at least 1.8 m. Scraping straight-edges which operate in conjunction with regulating machines shall pass across the surface at right angles to the longitudinal axis of the carriageway. If the surface is torn by the straight-edge, the surface shall be regulated again by the regulating machine or vibrating beam and by the scraping straight-edge.

(e) Wooden floats shall not be used to tamp and regulate small areas of the carriageway

unless permitted by the Project Manager; steel floats or trowels shall not be used. 10.4.15 Surface texturing

(a) After the surface of the concrete carriageway has been regulated and before the curing compound is applied, the surface, other than the surface of channels and edges of slabs which do not require to be textured, shall be textured by brushing with a wire broom.

(b) The wire broom shall be at least 450 mm wide and shall have two rows of tufts. The

rows shall be 20 mm apart and the tufts in each row shall be at 10 mm centres and in line with the centre of the gaps between the tufts in the other row. The tufts shall contain an average of 14 wires, each of 32 gauge and initially 100 mm long. The broom shall be replaced if any tuft wears down to a length of 90 mm.

(c) The surface texture shall be produced by brushing evenly across the slab in one

direction at right angles to the longitudinal axis of the carriageway. Brushing shall be carried out after the moisture film has disappeared from the concrete surface and before the initial set is complete.

10.4.16 Curing concrete

The surface and edges of concrete carriageways shall be protected by one of the methods stated in Clause 20.7.15 except that covering with hessian, sacking, canvas or other absorbent material as stated in Method 2 shall not be used. If Method 1 is used, the curing compound shall be applied to the surface immediately after the surface has been textured and shall be applied to the edges immediately after the formwork has been removed.

10.4.17 Protection of concrete carriageway

(a) Immediately after the curing system has been applied, the concrete carriageway shall be fenced off from pedestrian traffic and covered with protective sheeting for at least 24 hours. The sheeting shall be lapped and securely held in position in such a manner that the surface of the carriageway will not be damaged.

(b) Loads from materials not forming part of the Permanent Works or from Contractor's

Equipment or other vehicles shall not be applied to the concrete carriageway until at least 7 days after concreting has been completed and until all grooves at joints have been temporarily or permanently sealed or protected.

(c) When Contractor's Equipment or other vehicles will turn on the concrete carriageway

the Contractor shall lay a 100 mm thick protection layer of mesh reinforced 30/20 concrete over the turning area. The protection concrete shall be separated from the concrete carriageway by two layers of polythene and it shall be removed by the Contractor without damage to the concrete carriageway when construction traffic ceases.


10.4.18 Tolerances: sub-base

(a) The level of the formation below concrete carriageways shall not be more than 10 mm higher, and shall not be more than 40 mm lower, than the specified level.

(b) The level of the sub-base below concrete carriageways shall not be more than 10 mm

higher, and shall not be more than 20 mm lower, than the specified level. 10.4.19 Tolerances: formwork

(a) The line of formwork for concrete carriageways shall be within 10 mm of the specified line of the concrete carriageway.

(b) The level of the top of the formwork shall be within 3 mm of the specified level of the

concrete carriageway. (c) Abrupt irregularities in the line of the formwork and in the level of the top of

formwork shall not exceed 3 mm. 10.4.20 Tolerances: reinforcement

The cover to fabric reinforcement in concrete carriageways shall be within 10 mm of the specified cover.

10.4.21 Tolerances: dowel bars and tie bars

(a) Dowel bars at joints in concrete carriageways shall be within 20 mm of the mid-depth of the slab.

(b) Dowel bars shall be parallel to within 3 mm in half the length of the bar to:

(i) the longitudinal joint, or the longitudinal axis of the concrete carriageway if

there is no longitudinal joint;

(ii) the top surface of the slab; and

(iii) adjacent dowel bars. 10.4.22 Tolerances: grooves

The depth of grooves for joint sealant in concrete carriageways shall be within 3 mm of the specified depth.

10.4.23 Tolerances: covers, frames and other hardware

The level of covers, frames and other hardware shall not be higher than, and shall not be more than 3 mm lower than, the surface of the adjacent carriageway.

10.4.24 Tolerances: alignment of concrete carriageway

(a) The best fit straight line of straight joints and of straight edges of concrete carriageways shall be within 25 mm of the specified line. The line of straight joints and of straight edges of concrete carriageways shall be within 10 mm of the best fit straight line.


(b) The best fit curved line of curved joints and of curved edges of concrete carriageways shall be within 25 mm of the specified line. The line of curved joints and of curved edges of concrete carriageways shall be within 10 mm of the best fit curved line.

(c) Joints in concrete carriageways shall be continuous across intersections of joints to

within 5 mm of the best fit straight lines or best fit curved lines of each joint.

10.4.25 Tolerances: level of concrete carriageway

(a) The levels of the surface of concrete carriageways shall be determined 200 mm from the edges of each bay at 10 m centres in the longitudinal direction and at 2 m centres in the transverse direction.

(b) The level of the surface of concrete carriageways shall be within 6 mm of the

specified level. In low lying and flat areas the Contractor shall pay special attention to level control to ensure that falls on the surface of the carriageway are in the specified direction.

(c) The difference in level of the surface of concrete carriageways across joints shall not

exceed 3 mm. (d) The thickness of concrete carriageway slabs shall not be less than the specified

thickness minus 10 mm. 10.4.26 Rectification

(a) Where any tolerance is exceeded, the Project Manager will determine the full extent of the area which is out of tolerance and the Contractor shall make good the surface of the concrete carriageway as detailed in Clause 10.4.26(c).

(b) Where any joint tolerance is exceeded or joint construction does not meet

requirements stipulated elsewhere, the Project Manager will determine the full extent of the area to be made good and rectification shall comprise a minimum depth of 50 mm from the carriageway surface and a minimum distance of 50 mm from the area determined as requiring repair. Cut lines shall either be parallel to transverse joints or parallel to longitudinal joints and shall be sawn the full depth of the 50 mm. The remaining area shall be broken out by a method, reviewed without objection by the Project Manager and the repair shall be undertaken using thin bonded concrete.

(c) High areas shall be ground or milled down to within tolerance or regularity and the

surface texture to comply with Section 11. Low areas shall be rectified by cutting out the surface to a depth not less than 25 mm and replacing it with concrete of a mix and method of placement reviewed without objection by the Project Manager. Surface texture shall be restored to comply with Section 11.

10.5 INSPECTION, TESTING AND COMMISSIONING 10.5.1 Compliance criteria: trial mix concrete

The results of the tests on trial mix concrete for concrete carriageways shall comply with the following requirements: none of the six slump values shall not exceed 35 mm, and the average of the six slump values shall not exceed 30 mm.


10.5.2 Trial length

(a) A trial length of concrete carriageway shall be constructed to demonstrate that the proposed materials, mix design, methods of production and methods of construction will produce a concrete carriageway which complies with the Specification.

(b) The trial length shall be constructed using the materials, mix design, methods of

production and methods of construction submitted to and reviewed without objection by the Project Manager.

(c) Unless otherwise stated that the trial length shall be constructed in a location separate

from the permanent carriageway, the trial length shall comprise the first 30 m of the permanent carriageway. The trial length shall be constructed over a width of two bays and shall include at least one expansion joint, one contraction joint and the longitudinal joint between the bays.

(d) The Contractor shall notify the Project Manager at least 48 hours before constructing

the trial length. (e) The trial length shall be completed in sufficient time before the permanent

carriageway is constructed to allow the Project Manager a period of at least 7 days to determine if the specified requirements have been complied with in the trial length.

10.5.3 Testing: trial length

(a) The trial length shall be tested to determine the accuracy of the alignment and level, the surface regularity and the texture depth. The method of testing the surface regularity shall be as stated in Clause 10.5.8. The method of testing the texture depth shall be as stated in Clause 10.5.9.

(b) Concrete cores shall be cut from the trial length to determine the thickness of the slab,

the position of the reinforcement and joint components, the amount of segregation of the constituents and the presence of voids. The method of taking, preparing, inspecting and testing concrete cores shall be as stated in Clauses 10.5.11.

10.5.4 Compliance criteria: trial length

The results of tests on trial lengths shall comply with the following requirements:

(a) The alignment, levels and thickness of the carriageway shall comply with Clauses 10.4.24 and 10.4.25.

(b) The surface regularity shall comply with Clause 10.5.8(b). (c) The texture depth shall comply with Clause 10.5.9(b). (d) The positions of the reinforcement and joint components shall comply with Clauses

10.4.20, 10.4.21, 10.4.22 and 10.4.24. (e) The amount of segregation of the constituents and the presence of voids shall comply

with Clause 10.5.11(c).


10.5.5 Non-compliance: trial length

(a) If the result of any test on the trial length does not comply with the specified requirements for the trial length, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review; further trial lengths shall be constructed until the result of every test on the trial length complies with the specified requirements for the trial length.

(b) Trial lengths, or parts of trial lengths, which do not comply with the specified

requirements for the trial length shall be removed. 10.5.6 Commencement of concreting

(a) Concrete shall not be placed in the permanent carriageway other than in a trial length until the result of every test on the trial length complies with the specified requirements for the trial length.

(b) Concrete shall not be placed in the permanent carriageway before the results of tests

for compressive strength of the trial mix are available unless the result of every other test on the trial mix and trial length complies with the specified requirements for trial mix concrete and for the trial length.

10.5.7 Changes in materials and methods of construction

Unless permitted by the Project Manager, the materials, mix design, methods of production and methods of construction used to produce a trial length which complies with the specified requirements shall not be changed.

10.5.8 Testing: surface regularity

(a) Testing methodology: surface regularity

(i) Surface regularity of concrete carriageways shall be determined by measuring the number of irregularities in the surface. An irregularity means that the gap between the surface of the carriageway, and a 3 m straight-edge placed on the surface of the carriageway, exceeds the specified amount. Irregularities shall be measured in millimetres perpendicular to the straight-edge.

(ii) The longitudinal surface regularity of carriageways with a total length of 75 m

or more shall be measured using a rolling straight-edge of the type designed by the UK Transport and Road Research Laboratory. The longitudinal surface regularity of carriageways with a total length of less than 75 m and the transverse surface regularity of carriageways shall be measured using a 3 m straight-edge.

(iii) The longitudinal surface regularity shall be measured along lines parallel to the

longitudinal axis of the carriageway at approximately 0.75 m and 2.25 m from the nearside edge of each carriageway lane. The transverse surface regularity shall be measured along lines at right angles to the longitudinal axis of the carriageway at 10 m intervals along the length of the carriageway.

(iv) Testing to determine the surface regularity shall be carried out by the

Contractor in the presence of the Project Manager.


(b) Compliance criteria: surface regularity

The results of tests for surface regularity of carriageways shall comply with the following requirements:

(i) the size and number of irregularities in the longitudinal direction shall not

exceed the size and permitted number of irregularities stated in Table 10.1; and

(ii) there shall be no irregularity exceeding 4 mm in a 3 m length in the transverse direction for Category A roads and there shall be no irregularity exceeding 7 mm in a 3 m length in the transverse direction for Category B roads.

Table 10.1: Permitted Irregularities in the Longitudinal Direction

Total length of

carriageway

Size of irregularity

Permitted number of irregularities

(Category A road)

Permitted number of irregularities

(Category B road)

> 4 mm (9 x total length)/75 (18 x total length)/75 < 75 m

> 7 mm 1 2

> 4 mm 9 in any 75 m length 18 in any 75 m length 75 m - 300 m

> 7 mm 1 in any 75 m length 2 in any 75 m length

20 in any 300 m length 40 in any 300 m length > 4 mm

9 in any 75 m length 18 in any 75 m length

2 in any 300 m length 4 in any 300 m length > 300 m

> 7 mm 1 in any 75 m length 2 in any 75 m length

Category A roads are roads with a legal speed limit greater than 70 km/hour; all other roads are Category B roads.

Irregularities greater than 7 mm shall also be counted as greater than 4 mm. No irregularity greater than 10 mm shall be permitted.

10.5.9 Testing : Texture Depth

(a) Testing: texture depth

(i) The texture depth of concrete carriageways shall be determined by the sand patch test. Tests shall be carried out at least 2 days after the surface texturing has been carried out and before the area is used by Contractor's Equipment or other vehicles.

(ii) Each carriageway lane shall be divided into sections of equal length not

exceeding 150 m. Tests shall be carried out at ten locations on each section at approximately equal spacings as directed by the Project Manager. No measurement shall be taken within 300 mm of the longitudinal edges of the sections.

(iii) Testing to determine the texture depth shall be carried out by the Contractor in

the presence of the Project Manager. The method of testing shall be in accordance with Appendix A10.1.


(b) Compliance criteria: texture depth

The results of tests for texture depth for each section of concrete carriageway lane shall comply with the following requirements:

(i) the average texture depth shall not be less than 0.7mm; and

(ii) not more than one out of the ten measured texture depths shall be less than 0.6

mm. 10.5.10 Testing : Concrete

(a) Testing: workability and compressive strength of concrete

Testing to determine the workability and compressive strength of concrete in concrete carriageways shall be as stated in Clauses 20.8.5 to 20.8.15 except as stated in Clauses 10.5.10 (b) and (c).

(b) Compliance criteria: workability of concrete

The average slump value of the two specimens taken from one sample of concrete shall not exceed the specified slump value by more than 10 mm.

(c) Samples: compressive strength of concrete

One sample of concrete shall be provided from each 25 m³ or 25 batches of concrete or from the amount of concrete produced each day, whichever is less.

10.5.11 Testing : Concrete Cores From Trial Lengths

(a) Samples: concrete cores from trial lengths

(i) Two concrete cores shall be provided from each bay, and one core shall be provided from each joint, of concrete carriageway in the trial length. The positions from which the cores are taken shall be as directed by the Project Manager.

(ii) Concrete cores shall be 150 mm diameter and shall be the full depth of the slab. Cores shall be taken as soon as the concrete has hardened sufficiently for the core to be taken.

(iii) The method of taking concrete cores shall be in accordance with CS 1.

(iv) Holes formed by taking concrete cores from trial lengths which form part of the

permanent carriageway shall be reinstated using the concrete mix previously reviewed without objection by the Project Manager; joints shall be repaired in accordance with the method submitted to and reviewed without objection by the Project Manager.

(b) Testing: concrete cores from trial lengths

(i) Each concrete core from trial lengths in concrete carriageways shall be

inspected to determine the thickness of the slab and the positions of the reinforcement and joint components. Each core shall be inspected for evidence of segregation of the constituents and for the presence of voids.

(ii) The method of preparing and inspecting concrete cores shall be in accordance

with CS 1.


(c) Compliance criteria: concrete cores from trial lengths

Concrete cores from trial lengths in concrete carriageways shall not show evidence

of segregation. The extent of voids in the core shall be "few" in accordance with Table 4 of CS 1 and there shall be no honeycombing.

10.5.12 Testing : Materials For Joints

(a) Batch: joint filler, joint sealant

A batch of joint filler or joint sealant shall comply with Clause 20.8.24.

(b) Samples: joint filler, joint sealant

Samples of joint filler or joint sealant shall comply with Clause 20.8.25.

(c) Testing: joint filler, joint sealant

Testing of joint filler and joint sealant for joints in concrete carriageways shall be as stated in Clauses 20.8.26 and 20.8.27 except as stated in Clause 10.5.12 (d).

(d) Testing: joint sealant

Each sample of joint sealant shall be tested to determine the application life, tack-free

time, resistance to flow, recovery, adhesion and cohesion in tension and compression and resistance to heat ageing. The method of testing shall be in accordance with BS 5212.


APPENDIX A10.1

DETERMINATION OF THE TEXTURE DEPTH OF CARRIAGEWAYS A10.1.1 Scope This method covers the determination of the texture depth of carriageways by the sand patch

test. A10.1.2 Materials The following material is required: dry natural sand, with a rounded particle shape, which has been washed and then screened

such that it meets the grading stated in table 10.1.1.

Table 10A.1.1 : Grading of Sand

BS test

Sieve

Percentage by

mass passing

600 m 100

300 m 95 - 100

150 m 0 - 6

A10.1.3 Apparatus The following apparatus is required: (1) a soft brush; (2) a robust measuring cylinder having an internal diameter of 20 mm ± 2 mm and a flat

top surface such that its internal volume is 25 mL ± 0.1 mL; (3) a flat wooden disc of 65 mm diameter with a 1.5 mm thick hard rubber disc attached

to one face and a handle fixed to the other face; (4) a steel rule calibrated to 1 mm; (5) a suitable wind shield; (6) a funnel with an outlet tube at least 100 mm long with a bore of between 4 mm and 6

mm, and capable of accepting a volume of at least 200 mL; (7) a steel straight edge for screeding off the measuring cylinder; and (8) a steel-wire brush.


A10.1.4 Procedure The procedure shall be as follows:

(1) the test location shall be at least 300 mm square. It shall be vigorously brushed ten times in two directions at right angles using the steel wire brush, and then dried and swept clean with the soft brush;

(2) sand shall be poured into the measuring cylinder to fill it to overflowing, and any

excess sand shall be screeded off using the straight edge. All sand on the outside of the cylinder shall be removed, taking care not to drop any sand onto the test location. Alternatively, this step in the procedure shall be carried out in a laboratory, and the sand transferred to a suitable container ready for pouring;

(3) the measured volume of sand shall be poured onto the centre of the test location

through the funnel to form a heap. The wind shield shall be used to protect the test location if required;

(4) the sand shall be spread outwards with a circular motion over the test location, using

the rubber-faced disc with its face parallel to the surface of the carriageway. This shall be continued until the patch of sand is approximately circular and will spread outwards no more;

(5) the size of the circular patch of sand shall be measured to the nearest 1 mm along

three diameters which are aligned at approximately 120 degrees to each other; (6) if the difference between the maximum and minimum of the three measurements

exceeds 20% of the average of the three measurements, then all the measurements shall be discarded and the test repeated at an adjacent location; and

(7) the test shall be repeated for all the ten test locations for each section of carriageway

lane. A10.1.5 Calculation

(1) The texture depth (T) for each test shall be calculated from the equation: T = 31000 / D2 mm where: D is the average of the three diameter measurements of the sand patch calculated to

the nearest 1 mm. (2) The average texture depth for the ten tests shall be calculated.

A10.1.6 Reporting of results The following shall be reported: (1) test location; (2) average diameter of the sand patch for each test to the nearest 1 mm;

(3) texture depth for each test to the nearest 0.1 mm; and

(4) average texture depth to the nearest 0.1 mm.


SECTION 11 MISCELLANEOUS ROADWORKS



(a) Earthworks shall comply with Section 7. (b) Sub-base material and bituminous materials shall comply with Section 9. (c) Joints in concrete shall comply with Section 10. (d) Formwork and finishes to concrete shall comply with Section 18. (e) Steel reinforcement shall comply with Section 19. (f) Concrete shall comply with Section 20. (g) Steelwork shall comply with Section 22.

11.1.2 Unit

Unit is a term used to describe a precast concrete paving slab or an interlocking block. 11.2 DESIGN AND PERFORMANCE CRITERIA 11.2.1 Design of pedestrian guard-railing

Pedestrian guard-railing which is proposed by the Contractor as an alternative to that stated in the Contract or which is erected as Temporary Works shall be designed in accordance with BS 3049, Table 1, Class C.

11.3 MATERIALS 11.3.1 Cement mortar

Cement mortar shall consist of one part of cement to three parts of fine aggregate by volume together with the minimum amount of water necessary to achieve a consistency suitable for the required work. Fine aggregates shall be sand or crushed rock to BS 1200 and shall pass a 5 mm BS test sieve.



11.3.3 Concrete mix : profile barriers

Concrete for concrete profile barriers shall be Grade 30/20.


11.3.4 Steel: pedestrian guard railing

Steel for pedestrian guard-railing shall comply with the following:

Hot finished seamless tubes : BS 6323:Part 3 Steel tubes and tubulars suitable for screwing to BS 21 pipe threads : BS 1387 Hot rolled sections : BS 4:Part 1 Hot rolled structural steel sections - equal and unequal angles : BS 4848:Part 4 Weldable structural steels : BS 4360.

11.3.5 Stainless steel: pedestrian guard railing

Stainless steel for pedestrian guard-railing shall be Grade 316 S 31 and shall comply with the following:

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels : BS 970:Part 1 Stainless steel tubes suitable for threading in accordance with BS 21 : BS 6362.

11.3.6 Aluminium: pedestrian guard railing

(a) Aluminium for pedestrian guard-railing shall be H 30 TF and shall comply with the following:

Wrought aluminium and aluminium alloys for general engineering purposes - plate, sheet and strip : BS 1470 - drawn tube : BS 1471 - bars, extruded round tubes and sections : BS 1474. (b) Aluminium shall be anodised to Grade AA 25 in accordance with BS 1615.

11.3.7 Bolts, nuts, screws, washers and rivets

(a) Bolts, nuts, screws, washers and rivets for pedestrian guard-railing shall comply with the following:

ISO metric black hexagon bolts, screws and nuts : BS 4190 ISO metric black cup and countersunk head bolts and screws with hexagon nuts : BS 4933 Metal washers for general engineering purposes : BS 4320 Rivets for general engineering purposes : BS 4620 Wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock : BS 1473.


(b) The length of bolts shall be such that the threaded portion of each bolt projects through the nut by at least one thread and by not more than four threads.

(c) Rag and indented bolts shall comply with BS1494 : Part 2. Expansion bolts and resin

bonded bolts shall be proprietary types reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

(d) Galvanized bolts, nuts, screws, washers and rivets shall be used with galvanized

pedestrian guard-railing unless shown otherwise in the Contract. Non-ferrous or stainless steel components shall be insulated from ferrous materials by a non-conductive insulator of a type reviewed without objection by the Project Manager.

11.3.8 Mesh infill Mesh infill for pedestrian guard-railing shall comply with BS 4483. The mesh infill shall be

free from surface defects, surface irregularities and mesh misalignment. 11.3.9 Storage of pedestrian guard-railing Pedestrian guard-railing shall be stored off the ground on level supports and in a manner

which will not result in damage or deformation to the guard-railing or in contamination of the guard-railing. Pedestrian guard-railing shall be protected from damage and damaged guard-railing shall not be used in the Permanent Works.

11.3.10 Beams for untensioned beam barriers

(a) Beams for untensioned beam barriers shall be formed from steel plates complying with BS 1449 : Part 1, type BHR, grade 43/25.

(b) The beams shall be capable of withstanding a tensile force of at least 300 kN and shall

not deflect by more than 40 mm when loaded centrally with a point load of 1 tonne over a simply supported span of 3 m.

(c) Beams shall comply with the following requirements:

(i) the base metal thickness shall be within 0.2 mm of the specified thickness;

(ii) the strip width shall be within + 2.5 mm and - 0 mm of the specified width;

(iii) the camber of the strip length shall be within 8 mm of the specified camber;

(iv) the beam shall be straight to within 1.5 mm in a 1.5 m length; and

(v) angles at bends shall be within 2 of the specified angle.

(d) Bolt slots in beams for connection to posts shall be prepared in the workshop by cold saw-cutting. The spacing of the slots shall be such that posts will be spaced at either 4 m or 2 m.

(e) Beams shall be hot-dip galvanized in accordance with BS 729 to a coating thickness

of at least 460 g/m². (f) Welds for end beam sections shall be full-penetration butt welds.


(g) Beams shall be shaped so as to present no sharp edges to traffic and except where shown on the Employer’s Drawings shall be straight and of uniform cross-section within manufacturing tolerances.

(h) The beams shall be separated from the posts by blocking-out pieces which are

fabricated from materials of the same quality as the posts. (i) Posts and blocking-out pieces shall be drilled to take the specified post bolts for

affixing the beams. 11.3.11 Posts for untensioned beam barriers

(a) Posts for untensioned beam barriers shall be formed from Grade 43A steel complying

with BS 4360. (b) Posts and blocking-out pieces shall be hot-dip galvanized in accordance with BS 729

to a coating thickness of at least 610 g/m². (c) Posts fabricated from hollow sections shall be sealed by welding mild steel sealing

plates over the open ends; the plates shall be at least 3 mm thick. (d) Posts shall be within the tolerances stated in BS 4.

11.3.12 Anchorages for untensioned beam barriers

(a) End beam sections shall be cut and welded with full-strength butt welds. (b) Anchor blocks shall be constructed of concrete which shall be cast directly against the

sides of the excavation. 11.3.13 Cleats and struts for untensioned beam barriers

(a) Cleats and struts for untensioned beam barriers shall be fabricated from angle sections complying with BS 4 and shall be weldable structural steel complying with BS 4360, Grade 43A.

(b) Cleats and struts shall be hot-dip galvanized in accordance with BS 729 to a coating

thickness of at least 610 g/m². (c) The dimensional tolerances of steel angles for cleats and struts shall comply with

BS 4. 11.3.14 Bolts and nuts for untensioned beam barriers

(a) Bolts for untensioned beam barriers shall be M 16 size and strength grade 4.6 complying with BS 4190. Bolts for beam splicing, bolts for connecting beams to posts and bolts for connecting beams to cleats shall be round or button-headed with oval shoulders; other bolts shall be ISO metric black hexagon type.

(b) Nuts for untensioned beam barriers shall be of strength grade 4 or 5 complying with

BS 4190. (c) Bolts and nuts shall be hot-dip galvanized in accordance with BS 729 to a coating

thickness of at least 375 g/m².


(d) Nuts shall be tapped 0.4 mm oversize to accommodate the galvanized coating. (e) The length of bolts shall be such that the threaded portion of each bolt projects

through the nut by at least one thread and by not more than four threads. (f) Rag and indented bolts shall comply with BS1494 : Part 2. Expansion bolts and resin

bonded bolts shall be proprietary types reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

11.3.15 Washers

(a) Washers for untensioned beam barriers shall be black mild steel and shall comply with BS 4320, Form E, F or G; washers shall be manufactured from steel complying with BS 1449 : Part 1, grade 250.

(b) Plain washers shall be 2 mm thick and shall be of dimensions suitable for use with

M 16 bolts and nuts. (c) Plain washers shall be hot-dip galvanized in accordance with BS 729 to a coating

thickness of at least 375 g/m². (d) Shaped washers shall have a thickness of at least 5 mm and shall be cast iron

complying with BS 3468; the washers shall be shaped to fit the curvature of circular hollow sections used as posts.

11.3.16 Storage of beams and posts Beams and posts for untensioned beam barriers shall be stored off the ground on level

supports and in a manner which will not result in damage or deformation to the beams and posts or in contamination of the beams and posts. Beams and posts shall be protected from damage and damaged beams and posts shall not be used in the Permanent Works.

11.3.17 Concrete kerbs, edgings and quadrants

(a) Concrete for kerbs, edgings and quadrants shall be Grade 30/20. Concrete for foundations and backings to kerbs, edgings and quadrants shall be Grade 20/20.

(b) Precast concrete kerbs, edgings and quadrants shall comply with BS 7263 : Part 1

except that the requirement for testing of water absorption shall not be applied. The nominal length of kerbs shall be 1 m and the nominal length of edgings shall be 750 mm.

11.3.18 Supply of precast concrete kerbs type K1 and K2

(a) Except as otherwise provided in paragraph (e) below precast concrete kerbs types K1 and K2 shall be obtained from the Correctional Services Department, Tai Lam Chung.

(b) The Contractor shall, within 6 weeks from the date for commencement of Works,

submit a programme prepared to such detail as the Project Manager may require showing a month by month batch forecast of the total kerb requirements. The Project Manager will forward this programme to the Superintendent of the Tai Lam Correctional Institute who will advise whether he will be able to fulfil the order to the programme required.


(c) The Contractor shall update this programme from time to time and shall provide the Project Manager with 3 months notice of his requirements for any particular batch. The Project Manager will forward a copy of this notice to the Superintendent who will confirm within 1 month of the date of the notice whether or not he will be able to supply the particular batch.

(d) Having regard to the progress of the Works and upon receipt of confirmation from the

Correctional Services Department that a particular batch or part thereof can be supplied the Project Manager will issue a copy of the Requisition Order to the Contractor who shall thereafter be responsible for agreeing with the Superintendent of Tai Lam Correctional Institute a suitable date and time for collection of the kerbs.

(e) If the Superintendent is unable to confirm within 1 month, as stated in paragraph (c),

that he will be able to supply any batch or part thereof or if the Project Manager so instructs the Contractor shall provide kerbs from his own source. Appropriate items are included in the Bill of Quantities for this eventuality.

11.3.19 Granite kerbs, edgings and quadrants

(a) Granite kerbs, edgings and quadrants shall be worked straight or circular. Corners shall be square and the top front and back edges shall be parallel. The length of granite kerbs and edgings shall be at least 600 mm.

(b) The ends of the kerbs, edgings and quadrants shall be chisel-dressed square to form a

close butt-joint with adjacent kerbs. Kerbs shall be chisel-dressed to a depth of at least 140 mm on the front face, at least 75 mm on the back face and for the full width of the top face.

11.3.20 Concrete for footways, cycletracks and paved areas

Concrete for footways, cycletracks and paved areas shall be Grade 30/20. 11.3.21 Cobble stone paving

Cobble-stone paving shall consist of stones placed in a 100 mm thick grade 30/20 concrete bed. The stones shall be roughly elliptical and have a maximum dimension not exceeding 150mm and a minimum dimension not less than 100mm.

11.3.22 Rubble stone facing and paving Rubble stone facing and paving shall consist of random stone whose maximum dimension

on the exposed face shall not be less than 300 mm, whose minimum dimension on the exposed face shall not be less than 200 mm and whose thickness shall not be less than 200 mm.

11.3.23 Paving slabs and interlocking blocks

(a) Concrete for precast concrete paving slabs shall be Grade 30. (b) Concrete for precast concrete interlocking blocks in footways and cycletracks shall be

Grade 30; concrete for precast concrete interlocking blocks in carriageways or areas to which vehicles will have access shall be Grade 45.

(c) The nominal maximum aggregate size of aggregate for concrete in precast units shall

be 10 mm.


(d) The dimensions of the precast units shall be within 3 mm of the specified dimensions; chamfers shall not exceed 8 mm.

(e) Paving slabs shall be square or rectangular and interlocking blocks shall be

rectangular unless otherwise selected in the Contract. (f) The colour of precast units shall be consistent over the area to be paved.

11.3.24 Sand for precast paving and blocking

(a) Sand for bedding precast units shall have the particle size distribution stated in Table 11.1. The sand shall have a moisture content exceeding 4% and not exceeding 8% at the time of laying.

(b) Sand for filling joints between precast units shall have the particle size distribution

stated in Table 11.2. The sand shall have a moisture content of less than 0.5% at the time of filling joints.

Table 11.1: Particle Size Distribution of Sand for Bedding Precast Units

BS test sieve size


10 mm 100

5 mm 85 - 100

2.36 mm 65 - 100

1.18 mm 40 - 98

600 m 25 - 72

300 m 10 - 35

150 m 0 - 15

75 m 0 - 10

Table 11.2 : Particle Size Distribution of Sand for Filling Joint between Precast Units

BS test sieve size Percentage by mass passing

2.36 mm 100

1.18 mm 90 - 100

600 m 60 - 90

300 m 30 - 60

150 m 15 - 30

75 m 5 – 10

11.3.25 Handling and storage of units Units shall be handled and stored on pallets to avoid damage to corners and chamfer edges.

Pallets shall be stored on a level base and in a manner which will not result in damage to the units or in contamination of the units. The units shall be protected from damage and damaged units shall not be used.


11.3.26 Storage of sand Sand for filling joints between units shall be stored in waterproof bags and shall be kept

under cover until used. 11.4 SUBMISSIONS 11.4.1 Particulars of concrete profile barriers

(a) The following particulars of the proposed methods of construction for concrete profile barriers shall be submitted to the Project Manager for review:

(i) particulars of formwork as stated in Clause 18.5.1 for in-situ construction using

fixed forms;

(ii) details of slip-form machine for in-situ construction between sliding forms; and

(iii) methods of manufacture, handling, transport, storage and fixing in position of precast units.

11.4.2 Particulars of pedestrian guard-railing

(a) The following particulars of the proposed pedestrian guard-railing shall be submitted to the Project Manager for review:

(i) a certificate from the manufacturer showing the manufacturer's name, the date

and place of manufacture and showing that the materials comply with the requirements stated in the Contract; and

(ii) details of alternative designs proposed by the Contractor, including drawings,

showing the proposals and that the pedestrian guard-railing has been designed in accordance with Clause 11.2.1.

11.4.3 Representative samples of materials Representative samples of the following proposed materials shall be submitted to the Project

Manager for review of the source and type of each material at the same time as particulars of the pedestrian guard-railing are submitted:

(a) each type of pedestrian guard-railing; (b) mesh infill; and (c) each type of bolt, nut, and washer.

11.4.4 Particulars of untensioned beam barriers

(a) The following particulars of the proposed materials and methods of construction for untensioned beam barriers shall be submitted to the Project Manager for review:

(i) a certificate from the manufacturer for beams in the format stated in BS 4360

showing the manufacturer's name, the date and place of manufacture and showing that the beams comply with the requirements stated in the Contract and including carbon equivalent values; and

(ii) details of installation method.


11.4.5 Representative samples of materials for untensioned beam barriers Representative samples of the following proposed materials shall be submitted to the Project

Manager for review of the source and type of each material at the same time as particulars of the material are submitted:

(a) Beams; (b) posts, cleats and struts; and (c) bolts, nuts and washers.

11.4.6 Particulars of units

(a) The following particulars of the proposed materials and methods of construction for paving slabs and interlocking blocks shall be submitted to the Project Manager for review:

(i) name and address of manufacturer;

(ii) a certificate from the manufacturer showing the manufacturer's name and the

date and place of manufacture and including results of tests for: compressive strength of concrete cubes at 28 days; and compressive strength of interlocking blocks; and

(iii) Contractor’s Drawings showing the layout of the units within the paved area.

11.4.7 Representative samples of materials Representative samples of each type of unit shall be submitted to the Project Manager for

review of the source and type of each unit at the same time as particulars of the unit are submitted.

11.5 WORKMANSHIP 11.5.1 Formwork: Concrete profile barriers

(a) Formwork for concrete profile barriers shall be steel. The Contractor shall take measures, reviewed without objection by the Project Manager, to avoid retention of air bubbles on the inside face of the formwork.

(b) Formwork shall not be loosened or removed until at least 7 hours after concreting has

been completed. 11.5.2 Finishes to concrete: Concrete profile barriers

(a) The finish to unformed concrete surfaces of concrete profile barriers shall be Class U5.

(b) The finish to concrete surfaces for transverse joints shall be Class F3 and the finish to

exposed concrete surfaces shall be Class F5.


11.5.3 Joints in concrete profile barriers

(a) Joints shall be formed in concrete profile barriers at locations which coincide with expansion or construction joints in the adjoining structure or carriageway or at intervals not exceeding 12 m, whichever is less.

(b) Joints in concrete profile barriers shall comply with Section 20.

11.5.4 Construction of concrete profile barriers

(a) Construction by slip-form machine

Construction of concrete profile barriers by slip-form machine between sliding forms shall be carried out in accordance with BS 5931. Slip-form machines shall comply with BS 5931, Appendix A.

(b) Construction using precast units

Precast concrete profile barriers shall be laid on a cement mortar regulating layer of between 10 mm and 40 mm thick.

11.5.5 Protection of concrete profile barriers Immediately after the formwork has been removed or the curing compound has been

applied, concrete profile barriers shall be protected by polyethylene sheeting for at least 24 hours from exposure to conditions which may affect the concrete. The sheeting shall be lapped and securely held in position in such a manner that the surface of the concrete will not be damaged.

11.5.6 Tolerances: concrete profile barriers

Concrete profile barriers shall comply with the following requirements:

(a) The horizontal dimensions of cross-sections shall be within 5 mm of the specified dimensions.

(b) The vertical dimensions of cross-sections shall be within 10 mm of the specified

dimensions. (c) The horizontal alignment along the centreline shall be within 10 mm of the specified

centreline. (d) The level of the formation shall be within 10 mm of the specified level. (e) The level of the top of the barriers shall be within 10 mm of the specified level. (f) The barriers shall form a smooth alignment.


11.5.7 Galvanizing to steel

(a) Steel components forming pedestrian guard-railing shall be hot-dip galvanized in accordance with BS 729 to a coating thickness of at least:

(i) 500g/m2 for railing other than on highway structures (ii) 600 g/m2 for highway structures

(b) Galvanizing to steel shall be applied after welding, drilling and cutting are complete. 11.5.8 Welding steel

(a) Welding for fabrication of pedestrian guard-railing shall be fillet welds. Welded surfaces shall be full depth clean and flush before application of the protective coating.

(b) Steel shall not be welded after galvanizing unless permitted by the Project Manager; if

permitted, the welded areas shall be free from scale and slag and shall be treated with a zinc-coating system reviewed without objection by the Project Manager.

11.5.9 Installation of pedestrian guard-railing

(a) Pedestrian guard-railing shall be installed to a smooth alignment to within 10 mm of the specified position and height or as directed by the Project Manager.

(b) Pedestrian guard-railing which is to be installed to a radius of less than 45 m shall be

curved in the workshop and shall not be made up of a series of straight lengths. (c) Pedestrian guard-railing shall be fixed to concrete using rag, indented, expansion or

resin bonded bolts and shall be bolted to metalwork. Bolts for fixing to concrete shall be fitted into pockets filled with cement mortar or resin grout.

11.5.10 Installation of untensioned beam barriers

(a) Untensioned beam barriers shall be ready for assembly when delivered to Site. Beams and posts shall be free from blisters, flux, uncoated spots and other defects.

(b) The horizontal alignment of fences shall not depart from the road alignment by more

than (+ or -) 30mm nor deviate from the straight by more than 12mm in any two section lengths. The horizontal centre line of the beam shall be 600mm above the edge of the adjacent carriageway or above the datum level shown on the Employer’s Drawings, within a tolerance of (+ or -) 30mm. In addition the deviation from the straight shall not exceed (+ or -) 6mm in any two section lengths.

(c) Beams which are to be installed to a radius of less than 45 m shall be curved in the

workshop. (d) Adjacent beams shall not connected by lap joints made in the direction of the adjacent

traffic movement to avoid vehicles striking beam ends. Bolts are to be so located that they present no projection to traffic.

(e) Untensioned beam barriers shall be fixed to concrete using rag, indented, expansion

or resin bonded bolts and shall be bolted to metalwork. Bolts for fixing to concrete shall be fitted into pockets filled with cement mortar or resin grout.


11.5.11 Compacted earth footings

(a) Sub-base material shall be deposited and compacted in the bottom 250 mm of pits for foundations of untensioned beam barriers with compacted earth footings. Fine fill material shall be deposited and compacted to the remainder of the pit. The sub-base material and fill material shall be compacted to obtain a relative compaction of at least 95% throughout.

(b) Posts for untensioned beam barriers shall be securely fixed in position during deposition and compaction of fill material.

11.5.12 Concrete footings

(a) Concrete for concrete footings shall be Grade 20/20. (b) The top surface of concrete footings shall be finished level with the adjoining ground

unless otherwise shown on the Employer's Drawings; the finish to the concrete surface shall be Class U5.

(c) Posts shall be surrounded with polyethylene sheeting before concrete is placed and

shall be securely fixed in position during concreting. 11.5.13 Anchor blocks

(a) Concrete for anchor blocks shall be Grade 20/20. (b) The finish to concrete surfaces of anchor blocks shall be Class F5 for formed finishes

and Class U5 for unformed finishes. 11.5.14 Construction of precast concrete and granite kerbs, edgings and quadrants

(a) Precast concrete and granite kerbs, edgings and quadrants shall be laid and bedded on a regulating layer of cement mortar; the thickness of the layer shall be at least 10 mm and shall not exceed 40 mm.

(b) Except as stated in this Clause, joints between each kerb, edging and quadrant shall

not exceed 10 mm in width and shall be filled and flush pointed with cement mortar. Joints in kerbs, edgings and quadrants at expansion joints on bridge decks shall be as stated in the Contract. Transverse expansion and contraction joints in kerbs, edgings and quadrants laid on or adjacent to concrete carriageways shall be in accordance with Clause 10.4.6(b).

(c) Radius kerbs shall be used for curves less than 10 m external radius.

11.5.15 Construction of in-situ kerbs, edgings and quadrants

(a) In-situ concrete kerbs, edgings and quadrants shall be constructed in accordance with BS 5931 and shall be laid by an automatic extrusion machine of a type reviewed without objection by the Project Manager.

(b) In-situ concrete kerbs, quadrants and edgings shall have regular sides, edges, arrises

and chamfers; the finish to the concrete surface shall be Class U5. Kerbs, edges and quadrants shall not be finished or dressed with cement mortar.


(c) Contraction joints shall be formed at intervals not greater than approximately 4 m. Transverse expansion and contraction joints in kerbs, edgings and quadrants which are laid on or adjacent to concrete carriageways shall be in accordance with Clause 10.4.6(b). Joints shall be flush pointed with cement mortar.

11.5.16 Tolerances: kerbs, edgings and quadrants

(a) The line of kerbs, edgings and quadrants shall be within 3 mm of the specified line. (b) The level of the top of kerbs, edgings and quadrants shall be within 3 mm of the

specified level.

11.5.17 In-situ concrete footways, cycletracks and paved areas

(a) In-situ concrete for footways, cycletracks and paved areas shall be laid in areas not exceeding 20 m². The finish to the concrete surface shall be Class U4.

(b) Expansion joints shall be formed in concrete footways and cycle tracks at a spacing of

not more than 8 metres. 11.5.18 Flexible surfacing to footways, cycletracks and paved areas

(a) Bituminous materials for footways, cycletracks and paved areas shall be laid and compacted with steel-wheeled and pneumatic-tyred rollers. Compaction shall start before the temperature of the newly laid material falls below 100C and shall continue until all roller marks have been removed. For locations where rollers cannot operate effectively, the bituminous material can be compacted by hand-operated mechanical compaction plant reviewed without objection by the Project Manager.

(b) Cores shall be taken in accordance with Clause 9.6.15(a) for the checking of air void

content and compacted layer thickness of the bituminous material for works with area of not less than 200 m2. For works with area smaller than 200 m2 but greater than 50 m2, at least 2 cores shall be taken from each layer of bituminous material laid. For works with area less than 50 m2, no coring is required unless otherwise instructed by the Project Manager.

(c) The cores taken in accordance with Clause 11.5.18(b) shall be tested to determine the

air void content. The average air void content of the cores shall be not less than 3% nor greater than 9%. If the test result does not comply with the specified requirement, 2 additional cores shall be taken at locations agreed by the Project Manager and the average air void content determined from these 2 cores shall replace the original value for compliance checking. Notwithstanding this, no cores shall have an air void content of less than 2.5% nor greater than 10%.

(d) Each core taken from the final surfacing layer shall also be measured to determine the

compacted layer thickness that shall not deviate by more than 5 mm from the specified thickness. If the measured thickness does not comply with the requirement, 2 additional cores shall be taken at locations agreed by the Project Manager and the average thickness determined from these 2 cores shall replace the original measured value for compliance checking.

(e) If no bulk sample is taken for determination of the Rice’s specific gravity, the

corresponding value obtained from the mix design shall be used in determining the air void content of the core unless other value is suggested by the Contractor and agreed by the Project Manager.


11.5.19 Protection of footways, cycletracks and paved areas Footways, cycletracks and paved areas shall not be used by Contractor's Equipment or

vehicles other than those which are essential to construct the subsequent work. 11.5.20 Cobble stone paving construction

The stones shall be placed on the concrete bed to such a depth that the nominal line of the horizontal diameter of the stones is about 10 mm below the finished concrete level. The clearance between each stone shall be 75 mm maximum and 40 mm minimum. Cement wash shall not coat the exposed surface of the stones. Before the Contractor places any cobble-stone paving in the Permanent Works he shall prepare, for review by the Project Manager, a 2 m square trial panel of finished cobble-stone paving.

11.5.21 Rubble stone facing and paving construction

Stones shall be carefully shaped to obtain as close a fit as possible at beds and joints. When placed on the ground the stones shall be placed on material trimmed and compacted to make a firm bed.

Rubble stone paving stones shall be bedded on 100 mm of concrete Grade 20/40 and sufficient space shall be left between stones to allow the joints to be filled completely with concrete or mortar. The stones shall be bedded on the concrete while it is still fresh, or alternatively the concrete shall be left with a rough finish and the stones shall be bedded on a thin layer of mortar after the concrete has set. No cavities shall be left under or between the stones.

11.5.22 Laying paving slabs and interlocking blocks

(a) Laying units

(i) Paving slabs and interlocking blocks shall not be laid until the layout of the units within the paved area has been reviewed without objection by the Project Manager.

(ii) Kerbs and edgings shall be completed before the units are laid; the compressive

strength of the concrete used for in-situ concrete kerbs and edgings shall be at least 20 MPa before units are laid.

(iii) Measures shall be taken to prevent water draining across or through the area

during laying, bedding and compaction of the units.

(iv) Laying of units shall start as soon as practicable after the formation has been completed. The formation shall be protected as stated in Clause 7.4.33 until laying starts.

(v) Interlocking blocks for carriageways and paved areas to which vehicles will

have access shall be laid in a herring-bone pattern unless otherwise stated in the Contract.


(vi) Units shall be cut to size where required using mechanical cutting devices. The cut edge shall be similar to that of an uncut unit and shall be true to line and free from chips and cracks.

(vii) On circular work where the radius is 12 m or less all flags shall be radially cut

on both edges to the required line.

(b) Laying sand

(i) A layer of sand shall be laid and shall be screeded and tamped to a uniform depth over the complete width of the area to be paved. The quantity of sand shall be sufficient to permit screeding to waste and to achieve a tamped thickness which exceeds 20 mm and does not exceed 30 mm.

(ii) The sand layer shall not be disturbed by additional compaction, foot-marks or

other damage after the layer has been screeded and tamped to the required level and before the units are laid.

(iii) Sand shall not be screeded and tamped more than 1 m in advance of the units

which have been laid.

(c) Bedding paving slabs

(i) Paving slabs shall be laid on the prepared sand layer immediately after screeding and tamping in such a manner that the sand is not disturbed.

(ii) Paving slabs shall be adjusted to form uniform joints between 2 mm and 3 mm

wide and shall be bedded into the final position using a wooden mallet or a plate vibrator fitted with a rubber base-pad.

(iii) Paving slabs shall not be bedded closer than 1 m behind the laying edge other

than on completion of the paved area against a kerb or edging.

(iv) Final levelling of the slabs shall be carried out as soon as practicable after bedding and before changes in the moisture content of the prepared sand layer occur.

(v) Damaged paving slabs shall be immediately removed and replaced.

(d) Bedding interlocking blocks

(i) Interlocking blocks shall be laid on the prepared sand layer immediately after

screeding and tamping in such a manner that the sand is not disturbed. Interlocking blocks shall be individually laid on the prepared sand layer by manual methods or in clusters by mechanical methods.

(ii) Interlocking blocks shall be laid in such a manner that the blocks are not in

direct contact with each other and that uniform joints of between 2 mm and 3 mm wide are formed. Interlocking blocks shall be bedded flush by at least two passes of a heavy-duty plate compactor fitted with a rubber base-pad.

(iii) Interlocking blocks shall not be bedded closer than 1 m behind the laying edge

other than on completion of the paved area against a kerb or edging.


(iv) Final levelling of the blocks shall be carried out as soon as practicable after bedding and before changes in the moisture content of the prepared sand layer occur.

(v) Damaged interlocking blocks shall be immediately removed and replaced.

(e) Filling joints and compaction of units

(i) After the units have been bedded, sand for filling the joints shall be spread over

the surface of the units and brushed into the joints in such a manner that all joints are completely filled.

(ii) Joints shall be filled as soon as practicable after bedding and on the day the

units are laid and bedded.

(iii) Paved areas shall be further compacted by at least two passes of a plate compactor fitted with a rubber base-pad after filling the joints to ensure that the joints are completely filled. Sand shall be added as required and compacted into the joints.

(iv) Carriageways and paved areas to which vehicles will have access shall be

compacted by at least ten evenly-spaced passes of a pneumatic tyred roller having a gross weight of between 10 t and 12 t. Sand shall be added as required and brushed and compacted into the joints.

(v) Excess sand shall be removed after completion of compaction.

(vi) Damaged units shall be immediately removed and replaced.

(f) Mortar and concrete seal

Pigmented mortar or concrete shall be placed to the full depth of the unit to form a

seal between units and adjacent kerbs, edgings, quadrants, covers, frames and other hardware. The pigment shall match the colour of the adjacent units.

(g) Reinstatement of units

(i) If excavation is to be carried out in paved areas constructed using paving slabs

or interlocking blocks, the units shall be extracted by manual methods for a distance of at least 300 mm beyond the limit of the excavation.

(ii) Unbroken units shall be thoroughly cleaned to remove all sand and deleterious

material. The units shall be stacked on pallets for re-use.

(iii) Units to be re-used shall be re-laid in accordance with Clauses 11.5.22(a) to 11.5.22(f).

(h) Tolerances: paving slabs and interlocking blocks

The level of paved areas constructed using paving slabs or interlocking blocks shall

be within 3 mm of the specified level. The difference in level of adjacent slabs shall not exceed 2 mm.


11.6 INSPECTION, TESTING AND COMMISSIONING 11.6.1 Trials : Concrete profile barriers

(a) Trial length concrete profile barriers

(i) A trial length of concrete profile barrier shall be constructed to demonstrate that the proposed materials, mix design, methods of production and methods of construction will produce a concrete profile barrier which complies with the specified requirements. If it is not stated in the Contract that the trial length is to be constructed in a location separate from the permanent concrete profile barrier, the trial length shall be the first 25 m of the permanent barrier.

(ii) The trial length shall be constructed in sufficient time before the permanent

barrier is constructed to allow the Project Manager a period of at least 7 days to determine if the specified requirements have been produced in the trial length.

(iii) The Contractor shall notify the Project Manager at least 24 hours before

constructing the trial length.

(iv) The trial length shall be constructed using the materials, mix design, methods of production and methods of construction submitted to and reviewed without objection by the Project Manager.

(v) The trial length shall be used as a means of comparison against which the

Project Manager shall determine the compliance or otherwise of the permanent concrete profile barrier. The trial length shall be protected from damage and shall be left in position unless the Project Manager directs its removal. A trial length which forms part of the permanent barrier and which complies with the specified requirements shall not be removed.

(b) Testing: trial length

(i) The trial length shall be tested to determine the accuracy of the alignment and

level and the finish of the concrete surface.

(ii) Concrete cores shall be cut from the trial length to determine the amount of segregation of the constituents and the presence of voids. The method of taking, preparing, inspecting and testing concrete cores shall be as stated in Clause 11.6.2.

(c) Compliance criteria : trial length

The results of tests on trial lengths shall comply with the following requirements:

(i) The alignment and levels of the barrier shall comply with Clause 11.5.6.

(ii) The finish of concrete surfaces shall comply with Clause 18.44.

(iii) The amount of segregation of the constituents and the presence of voids shall

comply with Clause 10.5.11 for concrete carriageways.


(d) Non-compliance: trial length

(i) If the result of any test on the trial length does not comply with the specified requirements for the trial length, particulars of proposed changes to the materials, mix design, methods of production or methods of construction shall be submitted to the Project Manager for review; further trial lengths shall be constructed until the result of every test on the trial length complies with the specified requirements for the trial length. Further trial mixes shall be made unless non-compliance of the trial length was not due to the concrete mix.

(ii) Trial lengths, or parts of trial lengths, which do not comply with the specified

requirements for the trial length shall be removed.

(e) Commencement of concreting

(i) Except as stated in Clause 11.6.1(e)(ii) concrete shall not be placed in the permanent barriers until the result of every test on the trial length complies with the specified requirements for the trial length.

(ii) Concrete may be placed in the permanent barriers before the results of tests for

compressive strength of the trial mix are available provided that the result of every other test on the trial mix and trial length complies with the specified requirements for trial mix concrete and for the trial length.

(f) Changes in materials and methods of construction

The materials, mix design, methods of production and methods of construction used

to produce a trial length which complies with the specified requirements shall not be changed. Further trial lengths shall be constructed to demonstrate any proposed changes.

11.6.2 Testing concrete profile barriers: concrete cores from trial lengths

(a) Two concrete cores shall be provided from each trial length of concrete profile barriers. The positions from which the cores are taken shall be as directed by the Project Manager.

(b) Samples, testing and compliance criteria for concrete cores from trial lengths shall be

as stated in Clauses 10.5.11(a)(ii) to (iv), 10.5.11(b) & (c) for concrete carriageways. 11.6.3 Testing : Characteristic compressive strength of interlocking blocks

(a) Batch: interlocking blocks

A batch of interlocking blocks is any quantity of interlocking blocks of the same type and size, of the same concrete grade, manufactured in the same place, covered by the same certificates and delivered to the Site at any one time.

(b) Samples: interlocking blocks

(i) One sample of each type of interlocking blocks shall be provided from every

1000 interlocking blocks or part thereof.

(ii) The number of interlocking blocks in each sample shall be five.


(c) Testing: interlocking blocks

(i) Each sample of interlocking blocks shall be tested to determine the characteristic compressive strength at 28 days.

(ii) The method of testing shall be as stated in Appendix 11.1.

(d) Compliance criteria : interlocking blocks

The characteristic compressive strength of a sample of interlocking blocks shall be:

(i) 30 MPa for blocks in footways and cycletracks; and

(ii) 45 MPa for blocks in carriageways and paved areas to which vehicles will have access.

11.6.4 Testing: Grading of bedding and filling sand

(a) Batch: bedding sand

A batch of bedding sand is any stockpiled quantity of sand not exceeding a maximum batch size of 25t . Each batch shall be of the same type produced at the same time, and delivered to Site at any one time.

(b) Batch: filling sand

A batch of filling sand is any quantity of bags of filling sand of the same source, covered by the same certificate and delivered to Site at any one time.

(c) Sample: bedding or filling sand

(i) One sample of bedding or filling sand shall be provided from each batch. The method of sampling shall comply with BS 812 Part 102.

(ii) The size of each sample shall be 10 kg.

(d) Testing

(i) Each sample shall be tested to confirm compliance with the grading requirements of Table 11.1.

(ii) The method of testing shall be in accordance with BS 812 Part 103.


APPENDIX A11.1

DETERMINATION OF CHARACTERISTIC COMPRESSIVE STRENGTH OF INTERLOCKING BLOCKS

A11.1.1 Scope

This method covers the determination of the characteristic compressive strength at 28 days of interlocking blocks by means of a load test.

A11.1.2 Apparatus


(1) A compression test machine complying with CS 1. Bearing faces of the platens on the test machine shall be at least as large as the interlocking blocks and shall have a flatness tolerance of 0.05 mm.

(2) If a test machine with platens smaller than the interlocking blocks is used, auxiliary

plates of adequate size shall be placed centrally between the platens and the interlocking block to be tested. The flatness tolerance of the bearing faces of the auxiliary platens measured in accordance with CS1 shall not be more than 0.05 mm and the thickness of the plates shall be at least 25 mm.

(3) Two pieces of packing, each with a thickness of between 5 mm and 6 mm and

dimensions exceeding the interlocking block by between 15 mm and 25 mm. The packing shall be plywood, chipboard or medium density hardboard.

A11.1.3 Procedure


(1) The interlocking block shall be capped on the running surface and underside with a suitable capping material in accordance with Clause 15.5.2 of CS 1 and immersed in water for at least 24 hours before compression.

(2) The interlocking block shall be placed symmetrically on the lower platen of the test

machine, between the two pieces of packing with the running surface facing upwards. (3) Load shall be applied without shock and shall be steadily increased at a constant rate

within a stress range of between 150 kPa/s and 700 kPa/s. (4) The load at which the interlocking block fractures shall be recorded as the breaking

load. (5) The test shall be repeated for the other four blocks.


A11.1.4 Calculation

(1) The compressive strength (C) of each interlocking block shall be calculated from the equation: W 2.5

C = __ x _______ MPa

A 1.5 + L

H where:

W is the breaking load (N) A is the nominal gross plan area based on the manufacturing dimensions of the

interlocking blocks or the area of the tested portion if the interlocking block size is reduced for testing (mm²)

L is the lesser of the two plan dimensions (mm) H is the thickness of the block (mm)

(2) The unbiased standard deviation (s) shall be calculated from the following equation:

_____________

C2 - 5(Cm)2

s = _______________ Mpa 4

where:

C² is the sum of the compressive strengths of the five interlocking blocks (MPa) Cm is the average of the compressive strengths of the five interlocking blocks

(3) The characteristic strength (Cc) of the batch shall be calculated from the following equation: Cc = Cm - 1.65s MPa where: Cm is the average of the compressive strengths of the five interlocking blocks as

stated in Clause A11.1.4(2) s is the unbiased standard deviation as stated in Clause A11.1.4(2)

A11.1.5 Reporting of results The following shall be reported:

(1) Source, name of manufacturer and type of blocks. (2) Identification marks of blocks.


(3) Date of manufacture of blocks.

(4) Nominal gross plan area of each block to the nearest 100 mm². (5) Nominal height of each block to the nearest mm. (6) Breaking load of each block to the nearest kN. (7) Compressive strength of each block to the nearest MPa. (8) Average of the five compressive strengths to the nearest MPa. (9) Unbiased standard deviation to the nearest MPa. (10) Characteristic compressive strength to the nearest MPa. (11) That the test method used was in accordance with this General Materials and



SECTION 12 TRAFFIC SIGNS, ROAD MARKINGS AND ROAD STUDS


(a) The works and materials specified shall comply with the Sections stated, unless otherwise stated in this Section.

(i) Steelwork shall comply with Section 22.

(b) Traffic signs shall be externally illuminated, internally illuminated, retroreflective,

non-retroreflective or a combination of these types as stated in the Contract. 12.2 DEFINITIONS AND ABBREVIATIONS 12.2.1 Road Markings

Road markings are white or yellow continuous or intermittent lines, letters, characters, figures, arrows or symbols marked on the carriageway to guide road users and pedestrians.

12.3 RELEVANT CODES AND STANDARDS 12.3.1 Traffic signs

(a) Traffic signs shall comply with the Road Traffic Ordinance, Cap 374 and its subsidiary legislation. Traffic signs for road tunnels shall comply with the Road Tunnels (Government) Ordinance, Cap 368 and its subsidiary legislation.

(b) The design of traffic signs, including letters, characters, numbers, symbols and

borders, shall be in accordance with conditions and restrictions imposed by the Commissioner for Transport.

(c) Unless otherwise stated in the Contract, traffic signs shall comply with the

following:

Internally illuminated signs and external lighting luminaires : BS 873 : Part 5

Retroreflective and non-retroreflective signs : BS 873 : Part 6

Posts and fittings : BS 873 : Part 7

except that the requirements for marking signs shall not apply.


12.4 MATERIALS 12.4.1 Steel

Steel for traffic signs shall comply with the following:

Hot finished seamless tubes : BS 6323 :Part 3

Hot rolled sections : BS 4 : Part 1

Hot rolled structural steel sections - equal and unequal angles : BS 4848 : Part 4

Weldable structural steels : BS 4360

12.4.2 Stainless steel

Stainless steel for traffic signs shall be Grade 316 S 31 and shall comply with the following:

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels

: BS 970 : Part 1

Stainless steel tubes suitable for threading in accordance with BS 21 : BS 6362

12.4.3 Aluminium

(a) Aluminium for traffic signs shall be H 30 TF and shall comply with the following:

Wrought aluminium and aluminium alloys for general engineering purposes - plate, sheet and strip - drawn tube - bars, extruded round tubes and sections

: : :

BS 1470 BS 1471 BS 1474

(b) Aluminium shall be anodised to Grade AA 25 in accordance with BS 1615. (c) Aluminium sheet shall be free from twisting, warping and buckling and the surfaces

shall be free from blemishes and other defects.


12.4.4 Bolts, nuts, screws, washers and rivets

(a) Bolts, nuts, screws, washers and rivets for traffic signs shall comply with the following:

ISO metric black hexagon bolts, screws and nuts : BS 4190

ISO metric black cup and countersunk head bolts and screws with hexagon nuts

: BS 4933

Metal washers for general engineering purposes : BS 4320

Rivets for general engineering purposes : BS 4620

Wrought aluminium and aluminium alloys for general engineering purposes - rivet, bolt and screw stock

: BS 1473

General inspection and testing procedures and specific requirements for carbon, carbon manganese and stainless steels

: BS 970 : Part 1

(b) The length of bolts shall be such that after assembly the threaded portion of each bolt

projects through the nut by at least one thread and by not more than four threads. (c) Rag and indented bolts shall comply with BS 1494 : Part 2. Expansion bolts and resin

bonded bolts shall be a proprietary type reviewed without objection by the Project Manager and shall be capable of withstanding the design loading.

(d) Galvanised bolts, nuts, screws, washers and rivets shall be used with traffic signs

secured to galvanised pedestrian guard-railing. Aluminium materials shall be insulated from ferrous materials including any coated ferrous materials by a non-conductive insulator at least 2 mm thick of a type reviewed without objection by the Project Manager.

12.4.5 Materials for faces of traffic signs

(a) Retroreflective sheeting shall be Class 1 material complying with BS 873 : Part 6, Tables 1 and 2.

(b) Non-retroreflective sheeting shall comply with BS 873 : Part 6. (c) Plastic sheeting shall be a proprietary type reviewed without objection by the Project

Manager. (d) All materials and finishes shall be mutually compatible.

12.4.6 Hot applied thermoplastic material

(a) Hot applied thermoplastic material shall comply with BS 3262 : Part 1 except that:

(i) the softening point measured in accordance with BS 3262 : Part 1, Appendix E, shall not be less than 85C; and

(ii) the flow resistance shall be such that a cone made and tested in accordance with

BS 3262 : Part 1 shall not slump by more than 25% after 48 hours at 40C ±2C.


(b) Solid glass beads shall be included in the supplied mixture of hot applied

thermoplastic material.

(c) Binder for thermoplastic material shall be synthetic hydrocarbon resin or natural resin based as stated in the Contract.

12.4.7 Cold applied preformed material

(a) Cold applied preformed material for road markings shall be a proprietary type reviewed without objection by the Project Manager

(b) Solid glass beads shall be applied to cold applied preformed material at the place of

manufacture.

12.4.8 Paint for road markings

Paint for road markings shall comply with BS 6044. 12.4.9 Solid glass beads

Solid glass beads shall comply with BS 6088, Class B. 12.4.10 Delivery and storage of thermoplastic material

Hot applied thermoplastic material shall be delivered and stored in accordance with BS 3262: Part 1, Clauses 9 and 10 and the manufacturer's recommendations.

12.4.11 Road studs

(a) Road studs shall comply with the Road Traffic Ordinance, Cap 374 and its subsidiary legislation.

(b) Road studs shall be a proprietary type reviewed without objection by the Project

Manager. (c) Permanent reflecting road studs to be used as lane line markers on dual carriageway

trunk roads and primary distributor roads shall be a type to which traffic cylinders of a type reviewed without objection by the Project Manager can be attached. The method of attachment shall be such that the traffic cylinder can be easily detached from the road stud.

(d) Temporary reflecting road studs to be used as markers for temporary traffic routes

shall be yellow. 12.4.12 Bitumen grout

(a) Bitumen grout for road studs shall consist of bitumen and filler. The bitumen content shall be 25% to 30% of the total mass.

(b) Bitumen shall be tropical grade filled bitumen, oxidised grade R 85/25. (c) Filler shall be hydrated lime; the percentage by mass of hydrated lime passing a 75

m BS test sieve shall be at least 85%.


(d) The properties of bitumen grout for road studs shall comply with the following requirements:

(i) the penetration at 25C shall be 12±4;

(ii) the softening point shall be 105C ± 5C; and

(iii) the specific gravity shall not exceed 1.80.

12.5 SUBMISSIONS 12.5.1 Particulars of traffic signs

(a) The following particulars of the proposed traffic signs shall be submitted to the Project Manager for review:

(i) name of manufacturer; and

(ii) details of materials and finishes to be used in the manufacture of the signs.

12.5.2 Particulars of road markings

The following particulars of the proposed materials for road markings shall be submitted to the Project Manager for review:-

(a) certificates for thermoplastic material, paint and solid glass beads showing the

manufacturer's name, the date and place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests for softening point and flow resistance of thermoplastic material.

12.6 WORKMANSHIP 12.6.1 Posts for traffic signs

(a) Posts for beacons at zebra crossings shall be painted with alternate black and white stripes. Other posts shall be painted grey in accordance with BS 5252F, Code 18B19 or shall be galvanized in accordance with BS 729.

(b) Galvanised areas affected by cutting and drilling shall be treated using a method

reviewed without objection by the Project Manager. (c) Posts other than posts supporting an external luminaire shall not protrude above the

top of signs. The length of posts supporting external luminaries protruding above the top of signs shall be as short as practicable.

12.6.2 Backing plates for traffic signs

(a) Backing plates for traffic signs shall be fabricated from 3 mm aluminium sheet. Backing plates for traffic signs not exceeding 1200 mm high x 2400 mm wide shall be fabricated from a single sheet. If more than one sheet is used, the number of sheets shall be kept to a minimum; the separate sheets shall be rectangular and shall be approximately the same size.


(b) Holes in backing plates shall be drilled before the plate is painted and before retroreflective or non-retroreflective sheeting is applied.

12.6.3 Spill screens for traffic signs

(a) Top and bottom light spill screens shall be fabricated from the same material as the backing plate. The spill screens shall extend for the complete width of the backing plate and the corners shall be cut to the same radius as the corners of the backing plate.

(b) Spill screens shall be considered as part of the backing plate and stiffeners and

mountings shall be designed to accommodate the combined size. 12.6.4 Faces for traffic signs

(a) Faces for traffic signs shall be formed using retroreflective or non-retroreflective plastic sheeting. Unless otherwise permitted by the Project Manager, a single piece of sheeting shall be used. If more than one sheet is used, the number of sheets shall be kept to a minimum. Sheeting shall be fixed in accordance with the manufacturer's recommendations.

(b) Materials for faces of traffic signs, including the background, letters, characters,

numerals, symbols and borders, shall be matched for colour in accordance with the sheeting manufacturer's recommendations at the time of fabrication to provide a uniform appearance by day and by night.

(c) Letters, characters, numerals, symbols and borders shall be clear cut and sharp-edged

and shall have no cracks. (d) Sheeting material, including letters, characters, numerals, symbols and borders shall

be fully fixed using adhesive; there shall be no air bubbles, creases, cracks or other blemishes.

12.6.5 Lacquer coatings

Lacquer coatings to faces for traffic signs shall be uniform and continuous and shall be applied at the time of manufacture of the face.

12.6.6 Painting to faces for traffic signs

(a) Faces of traffic signs to which a painted or stoved finish is to be applied shall be thoroughly cleaned and pre-treated before painting and stoving.

(b) Pre-treatment shall be by anodising or by using an etching primer. (c) At least one undercoat and at least one finishing coat of paint shall be applied and

stoved to a thickness of between 0.0315 mm and 0.0375 mm of enamel over a minimum thickness of 0.025 mm of primer. If light colours are to be applied over dark colours, at least two coats of the light colour shall be applied. The final surface shall have a uniform thickness and an egg-shell flat finish and shall be smooth and free from defects.


(d) The colours of the finished coating shall be uniform. The colours, including white, shall comply with the chromaticity co-ordinates of BS 873 : Part 6, Table 4 and, for comparative purposes, shall comply with the following gloss paint colours in accordance with BS 381C:

- red : No. 537 - signal red; - orange : No. 557 - light orange; - yellow : No. 355 - lemon yellow; - blue : No. 109 - middle blue; and - green : No. 225 - light brunswick green.

(e) Parts of faces coloured black shall be non-retroreflective and shall have a luminance

factor not exceeding 0.05 as measured in accordance with BS 873 : Part 6. 12.6.7 Construction and assembly of traffic signs

(a) Fittings for traffic signs shall be non-corrodible material reviewed without objection

by the Project Manager. (b) Joints for framework and stiffeners which are not an integral part of the backing plate

shall be welded or joined using brackets, nuts, bolts and washers. (c) Materials for rivets and other fixings for joining backing plates to framework and

stiffeners shall be compatible with the materials to be joined. The spacing of rivets and other fixings shall be uniform; the spacing shall not exceed 150 mm around the outside edge of sheets and shall not exceed 300 mm on cross braces.

(d) An additional washer of neoprene or nylon shall be used to protect the faces of traffic

signs from metal nuts, bolts, washers and screws. (e) Backing plates shall be connected to posts by a method reviewed without objection by

the Project Manager. Banding systems shall be stainless steel. Drilling of holes in ferrous components shall be completed before finishes are applied.

(f) A lacquer coating shall be applied to the edges of holes drilled in plates with plastic

sheeting immediately before rivets and bolts are inserted. The surfaces of rivets and bolts on the faces of traffic signs shall be covered with a material coloured to match the part of the face with which it is in contact.

(g) Fixings for traffic signs erected on road lighting columns shall be compatible with the

column cross section. Columns shall not be drilled. 12.6.8 Covering of traffic signs

(a) Traffic signs which are to be blanked out shall be covered by the following methods:

(i) Plate signs shall be covered using a 1.5 mm thick sheet which is compatible with the material in the sign.

(ii) Plate signs which are to be blanked out for a period not exceeding one year

shall alternatively be covered using a self-adhesive plastic film.

(iii) Other signs shall be covered using a loose cover sheet of material reviewed without objection by the Project Manager.


(b) Cover sheets shall be fixed using 5 mm diameter stainless steel bolts, washers and nuts or non-ferrous rivets at spacings not exceeding 600 mm. Bolts shall pass through 5 mm x 12 mm diameter plastic distance pieces between the face of the sign and the cover plate. Holes which remain on the finished face of the sign shall be filled using blocked rivets; the face of the rivets shall be coloured by a method reviewed without objection by the Project Manager.

(c) Self-adhesive plastic film shall be compatible with the material in the face of the sign

and shall be fixed and removed in accordance with the manufacturer's recommendations.

(d) Loose covers shall be securely fastened to the back of the sign. Tape or other

adhesive material shall not be applied to the faces of signs. (e) Coverings to traffic signs shall be sufficiently opaque to prevent reflection from the

covered sign and shall not be removed until the Project Manager so directs. (f) The faces of traffic signs which have been erected and which do not relate either

wholly or in part to the traffic situation which applies at that time shall be blanked out as stated in this Clause.

12.6.9 Preparation of surfaces for Road markings

(a) Road markings shall not be laid over loose detritus, mud or similar extraneous matter. Oil and grease shall be removed from the surface of carriageways on which road markings will be laid.

(b) Curing compound shall be removed from the surface of new concrete carriageways on

which road markings will be laid, by wire brushing or by other methods reviewed without objection by the Project Manager.

(c) Existing road markings which are to be replaced by a different type of material shall

be removed by high pressure water jetting, shot blasting or rotary grinding; the existing markings shall not be masked using black paint or similar methods.

(d) Existing road markings which are to be renewed using a similar type of material shall

be roughened by a method reviewed without objection by the Project Manager until the thickness of the existing material is reduced by approximately 50%.

(e) A tack coat shall be applied to the surface of concrete carriageways before hot

thermoplastic material is laid. The tack coat shall be compatible with the road marking material and shall be applied in accordance with the manufacturer's recommendations.

(f) Rotary grinding machines shall not be used to remove or roughen existing road

markings within 100 mm of longitudinal or transverse joints on concrete carriageways.

12.6.10 Laying hot applied thermoplastic material

(a) Hot applied thermoplastic material shall be prepared and laid in accordance with BS 3262 : Part 3, Clauses 4 and 5. The material shall not be laid when the surface of the carriageway is wet, or the air ambient temperature in the shade is less than 10C.


(b) Hot applied thermoplastic material shall be laid by machine or by screeding methods. The machine or apparatus shall be capable of producing a marking to a uniform thickness and width; the marking shall have clean edges and shall be free from streaks and blisters.

(c) The thickness of road markings, not including surface applied solid glass beads, shall

comply with the following:

(i) screed markings : 4 mm;

(ii) sprayed lines other than yellow edge lines : 1.5 mm; and

(iii) sprayed yellow edge lines : 0.8 mm.

The thickness shall be measured in accordance with BS 3262 : Part 3, Appendix B.

(d) Traffic shall not be permitted to run over road markings until they are dry and set. 12.6.11 Laying cold applied preformed material

(a) Cold applied preformed material shall be laid in accordance with the manufacturer's recommendations. The material shall not be laid when the surface of the carriageway is wet.

(b) The thickness of road markings shall be at least 1.5 mm. (c) Traffic shall not be permitted to run over road markings until they are dry and set.

12.6.12 Use of road marking paint

Road marking paint shall not be used other than for temporary road markings. 12.6.13 Reflectorisation

Solid glass beads shall be applied to the surface of hot applied thermoplastic material and road marking paint immediately after the material or paint has been applied, to enhance the reflectivity of the surface. The solid glass beads shall be uniformly applied by a mechanical method at a rate of between 400 g/m² and 500 g/m².

12.6.14 Temporary road markings

(a) Temporary road markings shall be used at locations directed by the Project Manager. Cold applied preformed material shall be used for temporary road markings which are to be removed.

(b) Temporary road markings shall be disposed of by the Contractor after removal. All

traces of tape shall be removed from the surface of the carriageway and existing permanent road markings shall be made good such that it is safe to allow traffic to use the road.

12.6.15 Skid resistance level

The skid resistance level of road markings measured in accordance with BS 3262 : Part 1 shall be at least 45.


12.6.16 Tolerances: road markings

The lengths, thicknesses and widths of hot applied thermoplastic material road markings shall comply with the following requirements:

(a) The thickness of screed markings shall be within 1 mm of the specified thickness. (b) The length and width of screed markings and sprayed lines shall be within +10%, -5%

of the specified dimension. 12.6.17 Installation of road studs

(a) Road studs shall be installed in accordance with the manufacturer's recommendations. (b) Depressible road studs shall be installed using bitumen grout. (c) Road studs shall not be installed on concrete carriageways until the concrete has

reached the specified grade strength. (d) Surfaces to which bonded road studs are to be fixed shall be clean and all dust, grease

and other deleterious material shall be removed immediately before the studs are installed.

12.7 INSPECTION, TESTING AND COMMISSIONING 12.7.1 Testing : traffic signs

(a) The number of traffic signs to be tested shall be as stated in the Contract or as directed by the Project Manager.

(b) The number and type of tests to be carried out on the traffic signs shall be as stated in

the Contract or as directed by the Project Manager. (c) Testing shall be carried out in such a manner that the traffic sign will not be damaged. (d) Testing shall be carried out by the Contractor at a laboratory reviewed without

objection by the Project Manager. 12.7.2 Compliance criteria : traffic signs

The compliance criteria for testing traffic signs shall be in accordance with BS 873:Part 1.


SECTION 13 WORK FOR ELECTRICAL AND MECHANICAL INSTALLATIONS

13.1 GENERAL

13.1.1 General requirements

(a) The works and materials specified in the following sub-clauses shall comply with the Sections stated, unless otherwise stated in this Section.

(i) Earthworks shall comply with Section 7.

(ii) Structural steelwork shall comply with Section 22.

(b) For the purposes of this Section 13 of the General Materials and Workmanship

Specification, the term electrical and mechanical work shall consist of all mechanical and electrical services, systems and equipment including but not limited to the following :

(i) heating, ventilation and air-conditioning systems; (ii) refrigeration systems;

(iii) gas systems;

(iv) electrically powered systems;

(v) high and low voltage electrical distribution systems;

(vi) lighting systems;

(vii) lightning protection systems;

(viii) earthing systems;

(ix) fire services systems;

(x) hydraulic, plumbing and drainage systems;

(xi) video, data and voice communication systems;

(xii) control, supervisory and monitoring systems; (xiii) baggage handling systems;

(xiv) utility services;

(xv) lifts, escalators and moving walkway systems; and

(xvi) automatic people movement systems.

13.1.2 Concealed electrical conduit system

Concealed electrical conduit system is an electrical conduit system, including all bends, couplers, bushes, saddles, boxes, covers, plugs, draw wires and other conduit fittings, which is cast into concrete or fixed in chases in brickwork with a minimum cover of 20 mm or which is laid directly in the ground.


13.1.3 Requirements for electrical and mechanical installations

(a) The principle requirements for electrical and mechanical installations will be as shown on the Employer's Drawings. Confirmation of these provisions and identification of any other requirements, including holes, sleeves and recesses, shall be carried out in accordance with the requirements of the Section 11 of the General Specification.

(b) Where holes, sleeves and recesses are to be provided in concrete structures they shall

be formed prior to placing of concrete and shall not be cut through hardened concrete. (c) Where pipework, cables, cable trunking or trays, ducts or fire dampers or other

elements of electrical and mechanical system pass through structural or non-structural elements, the requirements of Sections 44-60 of the General Materials and Workmanship Specification shall apply.

(d) Holes, sleeves and recesses in internal floors, stairways and platforms shall be

protected with temporary covers until the electrical and mechanical installation starts. Holes, sleeves and recesses in roofs, external walls and external floors shall be sealed with watertight temporary covers reviewed without objection by the Project Manager until the electrical and mechanical installation starts.

13.2 MATERIALS 13.2.1 Electrical conduits and fittings

(a) Electrical conduits and fittings shall comply with BS 4568 : Parts 1 and 2 and shall have Class 4 heavy protection inside and outside. Conduits shall be heavy gauge with screw-end construction in steel and shall have an external diameter of at least 20 mm; conduits shall be longitudinally welded.

(b) Metal boxes for enclosing electrical accessories shall comply with BS 4662 and shall

have heavy protection inside and outside; the boxes shall be of preferred sizes and shall be 35 mm or 47 mm deep as appropriate. Circular ceiling boxes of deep pattern shall comply with BS 4568 : Part 2 and shall have Class 4 heavy protection inside and outside; the boxes shall be at least 60 mm deep internally.

(c) Circular boxes, dome covers and hook covers shall be cast iron. Bushes and plugs

shall be brass. 13.2.2 Cable ducts and fittings

(a) UPVC cable ducts for installation above ground or for casting into concrete shall be Class 0 UPVC pipes complying with BS 3506. Cable ducts for installation below ground shall be Class B UPVC pipes complying with BS 3506.

(b) Joints and fittings for use with UPVC cable ducts shall comply with BS 4346 : Part 1

and BS 4346 : Part 2. Solvent cement for UPVC pipes and fittings shall comply with BS 4346 : Part 3.

(c) Steel cable ducts shall be steel tubes complying with BS 1387, medium series,

screwed and socketed tubes and shall have screwed sockets suitable for screwing to BS 21, Table 2 pipe threads. The tubes, sockets, clamps and saddles for ducts shall be galvanized in accordance with BS 729.


13.2.3 Paint for conduit and duct systems

(a) Bituminous paint for steel conduits and steel cable ducts shall comply with BS 3416, type 1.

(b) Anti-rust paint for concealed electrical conduit systems shall be a proprietary type

reviewed without objection by the Project Manager. (c) Zinc chromate primer for cable duct systems shall comply with BS 4652. (d) Galvanizing paint for cable duct systems shall be a proprietary type reviewed without

objection by the Project Manager. 13.2.4 Fire barriers

Internal fire barriers shall be a type offering adequate fire resistance for the application. The material shall be reviewed without objection by the Project Manager in compliance with Fire Services Department requirements and shall be resistant to fire, smoke, gas and water.

13.2.5 Cement grout for electrical and mechanical installations

(a) Materials for grout shall comply with Section 20. (b) The different types of cement grout for electrical and mechanical installations shall

consist of ordinary Portland cement, sand and PFA in the proportions by mass stated in Table 13.1 together with the minimum amount of water necessary to achieve a consistency suitable for completely filling the voids. The mix shall contain a non-shrink admixture.

Table 13.1: Mix Proportions of Cement Gout

Type Mix proportions by mass

Cement Sand PFA

G1 1 - -

G2 1 3 -

G3 1 10 -

G4 1 - 7

13.2.6 Cables

(a) PVC insulated cables shall be single core of copper conductors, 450/750V grade and flame retardant PVC insulation to BS 6004.

(b) The current carrying capacity shall be in accordance with IEE Wiring Regulations.

Minimum size of cables shall be as follows unless other specified:

Lighting 2.5 sq mm Control 1.5 sq mm


(c) All wiring shall be carried out on the loop-in system and the wires shall be drawn into the conduits after the whole of this installation has been completed. No joints or connectors will be allowed in any such cable, except that connectors may be used in accessible positions with lighting fittings.

(d) All PVC insulated cables shall be installed in galvanized conduit. (e) All PVC/SWA/PVC cables shall be installed as shown on the Employer’s Drawings

and terminated in brass glands fitted with amour clamps. 13.3 WORKMANSHIP 13.3.1 Construction of conduit systems

(a) Concealed electrical conduit systems which are shown diagrammatically in the Contract shall be constructed as stated in Clause 13.3.1(b) to (g).

(b) Concealed electrical conduit systems shall be mechanically continuous and where

metallic conduits are used they shall also be electrically continuous and effectively earthed.

(c) Principal conduit runs shall be either vertical or horizontal. Tee pieces and elbows,

including those with provision for inspection, shall not be used.

(d) Joints shall be made using coupler units into which the ends of the conduits shall be inserted and tightened. Running couplings shall not be used unless permitted by the Project Manager; if permitted, the couplings shall be made by screwing each of the conduits half way into the coupler with a hexagonal lock nut against each end of the coupler.

(e) Adaptable boxes shall be provided at:

(i) every second bend;

(ii) after a bend and a straight run of 10 m or less; and

(iii) every 15 m in straight runs.

(f) Adaptable boxes for conduits installed in floor screeds shall have the lids set flush

with the adjacent floor; the boxes shall be covered with the same material as the remainder of the floor and shall remain accessible at all times.

(g) The clearance between conduits entering adaptable boxes and between adjacent or

parallel conduits shall be at least the nominal maximum coarse aggregate size of the concrete plus 5 mm.

13.3.2 Installation of conduit systems

(a) Concealed electrical conduit systems shall be arranged and installed in accordance with best trade practice and in such a manner that all cables can be drawn with ease and without damage.

(b) All conduit systems shall be installed fully in accordance with the requirements of the

current IEE Wiring Regulation.


(c) Bends in concealed electrical conduit systems shall be formed by using proprietary bending equipment of a type reviewed without objection by the Project Manager; connections and other work shall be carried out using purpose made equipment.

(d) Conduits shall not be bent by more than 90 and the internal radius at bends shall be

at least 2.5 times the external diameter of the conduit. Conduits shall not be flattened at bends.

(e) Burrs and sharp edges shall be removed from the ends of conduits before installation. (f) Concealed electrical conduit systems which are to be cast into concrete shall be

fastened to the reinforcement with tying wire of the same type used for the reinforcement. The conduit systems shall not be positioned between the reinforcement and the outside face of the concrete.

(g) Conduit boxes shall be of a compatible size and shall have a single extension ring of

the required depth if the plaster finish exceeds 13 mm thick; multiple extension rings shall not be used.

13.3.3 Terminations of conduit systems

Screw fitting couplers shall be provided at each end of conduits which terminate in distribution boards, busbar chambers, motor starters, cable ducts, boxes or similar termination points. The item at which the conduit terminates shall be drilled with an unthreaded clearance hole to receive a brass male bush; the bush shall be screwed into the coupler from the inside of the item in such a manner that the surface of the item is gripped between the coupler and the bush. The threads shall be at least half the length of the coupler.

13.3.4 Protection of conduit systems

(a) Concealed electrical conduit systems shall have special arrangements designed by the Contractor to permit movement of conduits to take place on each side of movement joints in structures. A separate circuit protective conductor shall be installed to maintain effective electrical continuity across the joint. The protective conductor shall have a cross-sectional area rated to suit the largest live conductor to be drawn into the conduit.

(b) Steel conduit systems laid in contact with or adjacent to other metal work shall have

efficient and permanent metallic connection made between the conduit and the metal work.

(c) Underground steel conduits and conduits in contact with soil shall be painted with two

coats of bituminous paint before installation. (d) Exposed threads and damage to protective coatings of conduit systems shall be

painted with two coats of anti-rust paint. (e) Conduits shall be laid in such a manner that accumulation of condensed moisture in

the conduit system is prevented; measures shall be taken to prevent water from entering the system.

(f) Water, moisture and deleterious material shall be prevented from entering permanent

and temporary terminations in concealed electrical conduit systems, including conduit boxes, by using conduit stopping plugs of a type reviewed without objection by the Project Manager; paper or rags shall not be used.


13.3.5 Cleaning of conduit systems

After installation, concealed electrical conduit systems shall be swabbed out with draw-in tapes and absorbent cloth of a type reviewed without objection by the Project Manager; all obstructions shall be removed and draw wires shall be installed. After cleaning, exposed conduit ends shall be sealed as stated in Clause 13.3.4(f).

13.3.6 Installation of cable duct systems

(a) Changes in direction in cable duct systems shall be constructed in such a manner that the cables in the duct will have radii of curvature of at least 800 mm. Ducts entering draw-in pits shall be on the same horizontal plane as the draw-in pit.

(b) UPVC cable ducts shall be jointed in accordance with the manufacturer's

recommendations. (c) Steel cable ducts shall be jointed using screwed galvanized sockets and spun yarn

such that the jointed pipes abut; the threads shall be painted with two coats of bituminous paint. Internal rags and burrs shall be removed to provide a smooth bore through joints in the cable duct system.

(d) Surface mounted cable ducts shall be secured by galvanised steel clamps or saddles at

spacings not exceeding 3 m. (e) Ducts laid in the ground shall be kept at least 150 mm clear of gas and water mains

and all other utility services. In the case of any type of electricity supply the following minimum separating distance shall be provided:-

(i) High Voltage single core cables (exceeding 650 Volts) ......................... 450 mm

(ii) High Voltage multi-core cables (exceeding 650 Volts) .......................... 300 mm

In cases where it is not possible to provide the required clearance, a layer of concrete not less than 50 mm thick shall be provided between the duct and the electricity supply cable.

(iii) Low and Medium Voltage cables (not exceeding 650 Volts) ................. 150 mm

where the duct and electricity supply cable cross with minimum separation a layer of concrete 50 mm thick shall be provided.

(f) To ensure the correct alignment of ducts, a wooden mandrel shall be drawn forward

as the ducts are laid. 13.3.7 Protection of cable duct systems

(a) After jointing, exposed bare metal in cable duct systems shall be cleaned and painted with two coats of zinc chromate primer and two coats of galvanizing paint.

(b) Surface mounted galvanized steel cable ducts shall be cleaned and painted after

fittings and jointing have been completed.


13.3.8 Cleaning of cable duct systems

After jointing, cable duct systems shall be cleaned internally by scrubbing with a cylindrical brush of a type reviewed without objection by the Project Manager. The ends of ducts, including ends of ducts in draw-in pits and spare ducts, shall be fitted with tapered hardwood plugs to prevent water, moisture and deleterious material from entering the system and a 6 mm diameter nylon draw line shall be installed. The plugs shall be centrally drilled for the draw line and the draw line shall be secured by a knot tied on the outer face of the plug to leave at least 1500 mm of surplus line at each plug.

13.3.9 Electrical earthing systems

(a) Pits and trenches for electrical earthing systems shall be excavated at positions and at

the times directed by the Project Manager. (b) After the electrical earthing systems have been installed fill material shall be

deposited and compacted in the pits and trenches to a depth of 300 mm above the electrical earthing system. Fill material shall be sand or fine fill material which has been selected from the excavated material, and which is free from stones retained on a 20 mm BS test sieve. Fill material shall be compacted by handrammers in a manner reviewed without objection by the Project Manager.

(c) The Contractor shall supply and install 1 no. 16mm diameter copper earth rod, with

sufficient length for the pillar box, to ensure earth continuity complete with concrete lined pits with removable lids to enable access to the connection between the earthing electrode and earth lead to be obtained. The earth pits shall be at ground level sited as close as possible to the pillar box and the earth lead shall be 25 x 3mm copper tape.

13.3.10 Grouting for electrical and mechanical installations

(a) Grouting to structural steelwork, machine bases, crane rails, electrical and mechanical equipment and other electrical and mechanical installations shall comply with the requirements stated in Clause 13.3.10(b) to (g).

(b) The Contractor shall notify the Project Manager before items or equipment are

grouted. (c) Concrete surfaces shall be scabbled to remove laitance and loose material and to

expose the aggregate before the item or equipment is installed in position. (d) The voids to be grouted shall be cleaned and thoroughly wetted immediately before

grouting. Excess water shall be removed by using a compressed air jet. (e) Grout shall be mixed and placed by methods reviewed without objection by the

Project Manager. (f) If grouting is to be carried out in two operations, holding down bolts shall be grouted

into preformed pockets and sufficient time shall be allowed for the grout to cure and for the bolts to be tensioned before the remaining voids are grouted.


(g) Exposed grout surfaces shall have a uniform, dense and smooth surface free from trowel marks and which is produced by steel trowelling the surface under firm pressure. The exposed surfaces shall be cured by either:

(i) using a liquid curing compound applied to the surface by a low-pressure spray

until a continuous visible covering is achieved; or

(ii) covering the surface with hessian or sacking; the hessian or sacking shall be lapped and securely held in position and shall be kept damp for at least 4 days.

13.3.11 Completion of work for electrical and mechanical installations

(a) Unless otherwise stated in the Contract work shall be completed to the conditions stated in Clause 13.3.11(b) to (g) inclusive before structures are made available to Other Contractors for electrical and mechanical installations.

(b) Structures shall be clean, dry and free from dust. Work which will produce large

quantities of dust shall be complete. (c) Holes and recesses, concealed electrical conduit systems and cable duct systems

required for the installation shall be complete. Concrete surfaces on which items and equipment are to be installed shall be scabbled.

(d) Plinths, trenches, louvres, openings and similar work shall be complete and shall have

hardened sufficiently to allow the installation to proceed. (e) Floors and slabs shall be complete to the specified finishes except that floor tiles shall

not be laid until after the installation is complete. (f) Plant rooms shall be complete, including fixtures and fittings, to a secure and

weatherproof condition. Two sets of door keys for each plant room shall be provided for the Project Manager.

(g) Paintwork and similar finishes in plant rooms shall be complete to undercoat level;

final coats shall not be applied until after the installation is complete. 13.3.12 Protection of work for electrical and mechanical installations

(a) Structures in which electrical and mechanical installations are being carried out shall be maintained in a clean, dry condition, free from dust, during the installation.

(b) The dust level in plant rooms shall be kept to a minimum by using industrial dust

extractors of a type reviewed without objection by the Project Manager during and after the installation. Temporary screens shall be installed to separate dust-affected areas from the installations or temporary covers shall be installed around the installation.

13.4 INSPECTION, TESTING AND COMMISSIONING 13.4.1 Inspection of work for electrical and mechanical installations

(a) The Contractor shall allow the Project Manager to inspect the following work for electrical and mechanical installations:


(i) completed concealed electrical conduit systems, cable duct systems, electrical earthing systems and items and equipment which are to be grouted or covered up;

(ii) items and equipment which are to be tested; and

(iii) structures which are to be made available for electrical and mechanical

installations.

(b) The Contractor shall notify the Project Manager three days, before work is covered up, tested or made available.

13.4.2 Testing: earthing continuity

(a) Concealed electrical conduit systems shall be tested to determine the earthing continuity. The system shall be tested:

(i) before the system is cast in concrete or covered up;

(ii) after the system is cast in concrete or covered up; and

(iii) after electrical wiring which is installed by the Contractor is complete.

(b) The method of testing shall be in accordance with the 16th Edition of IEE Wiring

Regulations issued by the Institution of Electrical Engineers. (c) The results of tests for earthing continuity shall comply with the 16th Edition of IEE

Wiring Regulations issued by the Institution of Electrical Engineers. 13.4.3 Testing: load tests on beams and joists

(a) Load tests shall be carried out on lifting beams, rolled steel joists, lifting hooks, eyes and anchorage points which are installed by the Contractor for electrical and mechanical work or other Permanent Works.

(b) Testing shall be carried out by an independent testing authority reviewed without

objection by the Project Manager and by using methods reviewed without objection by the Project Manager.

(c) A certificate showing the results of the load tests and signed by the testing authority

shall be submitted to the Project Manager for review within 7 days of the test. (d) The results of tests on lifting beams, rolled steel joists, lifting hooks, eyes and

anchorage points shall comply with the Factories and Industrial Undertakings (Lifting Appliances and Lifting Gear) Regulations, 1978 issued by the Labour Department.


SECTION 14 WATER SUPPLY PIPEWORKS 14.1 GENERAL 14.1.1 General requirements

The Permanent Works and materials specified below shall comply with the Sections stated, unless otherwise stated in this Section.

(a) Drainage works shall comply with Section 6. (b) Earthworks shall comply with Section 7. (c) Formwork and finishes to concrete shall comply with Section 18. (d) Concrete shall comply with Section 20.

14.2 DEFINITIONS AND ABBREVIATIONS 14.2.1 Fitting

Fitting is a component fitted to a pipe for jointing or connecting or for changing the direction or bore of a pipe.

14.2.2 Flexible joint

Flexible joint is a connection between pipes and fittings which provides angular deflection or axial movement or a combination of both in service without impairing the efficiency of the connection.

14.2.3 Mechanical joint

Mechanical joint is a flexible joint in which an elastomeric joint ring is located in the socket and the joint sealed by applying pressure to the joint ring by means of a gland bolted to the socket.

14.2.4 Nominal size

Nominal size is a numerical designation of size which is common to all components in a pipework system. The nominal size is stated as a convenient round number in millimetres and is related to, but not normally the same as, the actual internal diameter of the pipework; dn designates the nominal size of tees and tapers which are less than DN.

14.2.5 Push-in joint

Push-in joint is a flexible joint in which an elastomeric joint ring is located in the socket and the joint is effected by entering the spigot through the joint ring into the socket.

14.2.6 Special fitting

Special fitting is a fitting which is made from a manipulated or fabricated pipe.


14.2.7 Thin walled pipe

Thin walled pipe is a pipe, including pipes of DN 1200 or greater, which has a ratio of nominal size to wall thickness, excluding linings and coatings, exceeding 125.

14.2.8 Nominal outside diameter of a polyethylene pipe

Nominal outside diameter of a polyethylene pipe shall mean the minimum mean outside diameter of the pipe as described in Clause 3.1 of ISO 161-1.

14.2.9 Nominal wall thickness of a polyethylene pipe

Nominal wall thickness of a polyethylene pipe shall mean the minimum wall thickness of the pipe as described in Clause 3.4.5 of BS ISO 11922-1.

14.2.10 Standard Dimension Ratio

The Standard Dimension Ratio (SDR) of a polyethylene pipe shall mean the ratio of its nominal outside diameter to its nominal wall thickness as described in Clause 3.8 of ISO 161-1.

14.2.11 WIS

WIS shall mean the Water Industry Specification produced and published by WRC. 14.3 MATERIALS 14.3.1 Materials for water supply pipeworks

Materials for water supply pipeworks for potable water shall be non-toxic, shall not promote microbial growth and shall not impart a taste, odour, cloudiness or discolouration to the water after disinfection and washing out of the pipelines as stated in Clause 14.6.8. Water supply pipework shall be either ductile iron or polyethylene unless otherwise reviewed without objection by the Project Manager.

14.3.2 DI pipes and fittings

(a) DI pipes and fittings shall comply with BS 4772. Pipes and fittings other than collars, caps and blank flanges shall be lined internally with cement mortar in accordance with BS 4772, Clause 3.2. Linings shall be made with sulphate-resisting Portland cement complying with BS 4027.

(b) Pipes shall be externally coated with metallic zinc in accordance with BS 4772,

Clause 3.1. Fittings shall be externally coated with zinc rich paint in accordance with BS 4772, Clause 3.1.5(b). After zinc coating pipes and fittings shall be externally coated with a finishing coat of one of the following materials as stated in BS 4772, Clause 3.3:

(i) bitumen based hot applied coating material complying with Clause 23.22 and

BS 4147 : Type I, Grade C; or

(ii) bitumen based cold applied coating material complying with Clause 23.22 and BS 3416 : Type II.


14.3.3 Flanges

(a) DI flanges shall be cast-on or welded-on standard flanges complying with BS 4772. 14.3.4 Bolts and nuts

(a) Bolts and nuts for flanged joints shall comply with BS 4504 : Section 3.1, Section 6. (b) Bolts and nuts shall be compatible with the type of joint and shall be obtained from

the same manufacturer as the joint.

(c) Bolts shall be sufficiently long and shall be suitably threaded for jointing the relevant flanges.

14.3.5 Elastomeric joint rings

Elastomeric joint rings for DI pipes and fittings shall comply with BS 4772, Clause 2.3.4. The dimensions of rings for use with flanged joints shall comply with BS 4865 : Part 1. The rings shall be compatible with the type of joint and shall be obtained from the same manufacturer as the joint.

14.3.6 Polyethylene Pipes

(a) Polyethylene pipes shall be either PE80 or PE100 grade pipes in accordance with Clauses 14.3.6 (b) to (h)

(b) PE80 pipes with nominal outside diameter from 20mm to 63mm inclusive and PE100

pipes with nominal outside diameter from 90mm to 180mm inclusive shall conform to ISO 4427.

(c) PE80 and PE100 pipes shall have a SDR of 11 and have nominal pressure rating as

follows:

(i) PE80 – 12.5 bar (PN12.5); and (ii) PE100 – 16 bar (PN16).

(d) The colour for polyethylene pipes shall be blue within the range below:

Nominal Outside Diameter Colour Range

20mm – 63mm 18E51 to 18E53 of BS 4901

90mm – 180mm 20D44 to 20D45 or 20E53 to 20E56 of BS 5252

(e) The tolerance on the nominal outside diameter of polyethylene pipes shall be in

accordance with Grade B of BS ISO 11922-1. (f) The end of the pipe shall be cut cleanly and square to the axis of the pipe to within the

tolerances given below:

Nominal Outside Diameter Maximum Tolerance (mm)

90mm and below 2

125mm 3

180mm 4


(g) Standard length of polyethylene pipes supplied shall be 6 m. For pipes of nominal outside diameter from 20 mm to 63 mm, 50 m coils may be specified. No reduction in the specified length shall be allowed unless reviewed without objection by the Project Manager.

(h) Melt flow rate of PE80 and PE100 pipes tested at a temperature of 190°C under a

nominal load of 5 kg shall be within the range of 0.2 g/10 min to 1.3 g/10 min.

14.3.7 Fittings for Polyethylene pipes

(a) All fittings for polyethylene pipes shall have a pressure rating the same as or higher than the nominal pressure rating of the pipes. The fittings shall be supplied with complete set of accessories including insert, liners, joint rings, flange gaskets, studs, bolts and nuts, etc. whatever appropriate.

(b) The flanges of all fittings shall be constructed in such a way that they may be attached

to flanges designated PN16 whose dimensions conform to Table 9 of BS EN 1092-2. One complete set of bolts and nuts and one gasket shall be supplied with each flange of flanged fittings. The strength of bolts shall be Grade 4.8 and the strength of nuts shall be Grade 4 complying with BS 4190. The bolts and nuts shall be hot dip galvanized or have other protective coatings reviewed without objection by the Project Manager.

14.3.8 Polyethylene Electrofusion Fittings

(a) Polyethylene electrofusion fittings including couplers, reducers, socket ends tees, caps

and elbows, self tapping tee saddles and other electrofusion fittings shall comply with WIS 4-32-14. Polyethylene spigot fittings for electrofusion jointing including the spigot stub flange assembly shall comply with WIS 4-32-15. Stub flanges shall comply with WIS 4-24-01.

(b) Melt flow rate of PE80 and PE100 electrofusion fittings tested at a temperature of

190°C under a nominal load of 5kg shall be within the range of 0.2 g/19 min to 1.3 g/10 min.

(c) Notwithstanding Clause 5.1.6 of WIS 4-32-14, the fittings shall be capable of being

fused in the tropics. (d) The design for fitting terminals and shrouds shall be similar to that stated in Clause

5.2.3 of WIS 4-32-14. Other designs of terminals will only be considered if the Contractor can demonstrate that appropriate lead adaptor is readily available such that electrofusion of their fittings can be conducted using common electrofusion control units available in the market.

(e) Unless otherwise reviewed without objection by the Project Manager, all

electrofusion fittings shall be blue in colour within the range as specified in Clause 14.3.6(d).

14.3.9 Compression Fittings for Polyethylene Pipes

(a) Compression fittings for polyethylene pipes in a range of nominal outside diameter 20 mm to 63 mm inclusive, shall be Class 1 end-load bearing fittings conforming to ISO 14236.


(b) Compression fittings with external and/or internal threads shall be compatible with pipes and fittings threaded to BS 21.

14.3.10 Mechanical Fittings for Polyethylene Pipes

(a) Mechanical fittings for polyethylene pipes of nominal outside diameter 90 mm and

above shall be Type 1 fittings conforming to WIS 4-24-01. (b) Mechanical fittings shall be coated with a minimum thickness of 250 microns of

epoxy or plastic based coating complying with the performance requirement of WIS 4-52-01.

14.3.11 Markings on Polyethylene Pipes and Fittings

(a) Markings on the polyethylene pipes and fittings shall be in accordance with the

relevant Clauses in the ISO or WIS appropriate to the pipes and fittings supplied. (b) Notwithstanding Clause 8 of ISO 4427, the pipes series in SDR shall be marked on

the pipes. (c) Notwithstanding Clause 10 of ISO 14236, the designation of the material (PE80 or

PE100) and the number “ISO 14236” shall also be marked on the compression fittings.

14.3.12 Anticorrosion tape

(a) Anticorrosion tape shall be a propriety type reviewed without objection by the Project Manager. The tape shall either be a petrolatum tape with fabric reinforcement or a bituminous tape with PVC backing. Petrolatum tape shall be used for valves, flanged joints, slip-on type couplings and flange adaptors of all sizes. Bituminous tape shall be used in buried or non-exposed condition for welded joints of steel pipe, repair of steel pipe sheathing and other applications as specified on the Employer’s Drawings.

(b) Anticorrosion tapes shall have a high resistance to cathodic disbondment, acids and alkalis. Colour of bituminous tape shall be black. Anticorrosion tapes shall have as a minimum the properties stated in Table 14.1.

(c) Primer and mastic filler for use with anticorrosion tape shall be compatible with the tape and shall be a type recommended by the manufacturer of the tape and reviewed without objection by the Project Manager.

(d) Bituminous tapes shall be stored in a cool dry place away from the sun’s rays. The

tape shall be free of dirt or grit immediately prior to application.


Table 14.1: Properties of Anticorrosion Tape

Properties Petrolatum Tape Bituminous Tape

Thickness of PVC backing (mm) - 0.75

Total thickness (mm) 1.1 1.65

Mass (kg/m2) 1.4 2.0

Tensile strength (N/mm) 4 10

Adhesion strength

(180 peel)

Self

Steel

0.5

0.5

2.5

2.5

Dielectric strength (2 layers) (kV) 15 30

Elongation (at break) (%) - 260

Temperature range

(C)

Wrapping

Service

-5 to +45

-5 to +45

+5 to +50

-20 to +75

14.3.13 Bituminous coatings

(a) Bituminous coatings shall comply with the following:

Bitumen based hot applied coating material for protecting iron and steel including suitable primers where required : BS 4147, Type I, Grade C Black bitumen coating solutions for cold application : BS 3416, Type II.

(b) Bituminous coatings used for repairing joints and coatings shall be compatible with

the adjacent coating. (c) Bituminous coatings shall be made from petroleum or asphaltic bitumen.

14.3.14 Zinc-based paint

(a) Zinc-based paint shall be a proprietary type reviewed without objection by the Project Manager.

(b) Primers for zinc-based paint shall comply with BS 4652. (c) Rust inhibitor shall be a chemical agent which is capable of converting rust into iron

phosphate. 14.3.15 Joint filler and compressible padding

(a) Joint filler for joints in concrete bed, haunch and surround shall be a proprietary type reviewed without objection by the Project Manager and shall be a firm, compressible, single thickness, non-rotting filler. The thickness of the filler shall be as stated in Table 14.2.

(b) Compressible padding between pipes and supports shall be bitumen damp-proof

sheeting complying with BS 743.


Table 14.2: Joint Filler for Concrete Bed, Haunch and Surround

Nominal diameter of Pipe Thickness of joint filler (mm)

less than 450 mm 18

450 mm – 1200 mm 36

exceeding 1200 mm 54



14.3.17 Extension keys

Extension keys and clamps for valves shall be Grade 43A steel complying with BS 4360 and shall be hot-dip galvanised in accordance with BS 729 after fabrication.

14.3.18 Transport, handling and storage of pipes, joints and fittings

(a) Pipes, joints and fittings for water supply pipeworks shall be transported, handled and stored in accordance with the manufacturers' recommendations and in a manner which will not result in damage or deformation to the pipes, joints and fittings or in contamination of the pipes, joints and fittings.

(b) Pipes, joints and fittings shall be protected from damage and damaged pipes, joints

and fittings shall not be used in the Permanent Works. Pipes, joints and fittings shall be securely packed and supported to prevent movement when being transported.

(c) Bolts and nuts shall be packed in sealed metal containers. (d) Elastomeric joint rings shall be packed in bags and lubricant for joints shall be stored

in sealed containers marked to identify the contents. The rings and lubricant shall be protected from exposure to conditions which may affect the material.

(e) Boxed or crated materials or those in sealed containers shall remain in their original

boxes, crates or containers. 14.3.19 Handling of pipes and fittings

(a) Pipes and fittings other than thin walled pipes shall be handled by manual methods or by using lifting appliances or chains, wire rope or canvas slings of a type recommended by the pipe manufacturer and reviewed without objection by the Project Manager. Hooks shall not be used.

(b) Slings shall be placed around the pipes and fittings and padding shall be provided at

points of contact between pipes and fittings and metal lifting appliances or slings. Pipes and fittings shall not be handled by means of metal slings passed through the pipes.

(c) Pipes and fittings shall not be subjected to rough handling, shock loading or dropping.


14.3.20 Storage of pipes

(a) Pipes other than thin walled pipes shall be stored horizontally at least 75 mm above the ground on wedged timber bearers. The pipes shall be securely wedged to prevent sideways movement.

(b) Socket and spigot pipes shall be stored with the sockets alternating and in such a

manner that loads are not applied to the sockets. (c) The height of stacks of pipes other than thin walled pipes shall not exceed the

maximum height recommended by the pipe manufacturer. (d) Pipes shall not be strung out along the route of the pipeline.

14.3.21 Transport of thin walled pipes

When being transported, thin walled pipes shall be supported on three rubber covered saddles shaped such that the pipes are supported over at least one-quarter of the circumference. The pipes shall be securely fixed in position at each saddle by straps tightened by turnbuckles. One saddle shall be placed at the mid-point of the length of the pipe and the other two saddles shall be placed at distances of one-fifth of the length of the pipe from each end of the pipe.

14.3.22 Handling and storage of thin walled pipes

(a) When being handled and stored, thin walled pipes shall be protected from deformation by means of at least two screw jack cruciform struts with rubber padded ends shaped to fit the circumference of the pipes. The struts shall be fitted inside the pipes; any temporary struts fixed by the manufacturer shall be left in position until the cruciform struts have been fixed.

(b) Thin walled pipes shall be handled by using two reinforced canvas slings at least

300 mm wide. The slings shall be suspended from a lifting beam and shall be placed at a distance of one-fifth of the length of the pipe from each end of the pipe.

(c) Thin walled pipes shall not be rolled. (d) Thin walled pipes shall be stored on timber bearers padded with hessian or straw to

provide continuous support over at least one-third of the circumference of the pipe. The pipes shall be securely fixed in position with wedges placed at a distance of one-fifth of the length of the pipe from each end of the pipe.

(e) Thin walled pipes shall not be stacked on top of each other.

14.4 SUBMISSIONS 14.4.1 Particulars of independent inspection authority

Particulars of the proposed independent inspection authority for pipes, joints, fittings and valves for water supply pipeworks, including name and address, previous experience, and names of inspectors, shall be submitted to the Project Manager for review.


14.4.2 Particulars of pipes, joints and fittings

(a) The following particulars of the proposed pipes, joints and fittings for water supply pipeworks shall be submitted to the Project Manager for review:

(i) manufacturer's literature, including details of:

- manufacturing process; - pressure and temperature ratings; - permissible values of straight draws and angular deflection of flexible

joints; - re-commendations for handling, storage, laying, jointing and repair; and - drilling and tapping equipment for connections to pipes;

(ii) a certificate for each material showing the manufacturer's name, the date and

place of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests required in accordance with the relevant British Standard;

(iii) three copies of Contractor’s Drawings showing details of the pipes, joints and

fittings, including the materials used and the mass of each item; and

(iv) a certificate of inspection of the manufacture and testing signed by the independent inspection authority reviewed without objection by the Project Manager.

14.4.3 Particulars of pressure tests

(a) The following particulars of the proposed procedures for pressure tests on pipelines for water supply pipeworks shall be submitted to the Project Manager for review:

(i) test equipment and method of setting up the equipment;

(ii) calibration certificates for pressure gauges;

(iii) procedure for carrying out the test; and

(iv) programme for testing.

14.4.4 Particulars of Anticorrosion tape

The following particulars of the proposed anticorrosion tape for water supply pipeworks shall be submitted to the Project Manager:

(a) manufacturer’s literature for anticorrosion tape; and (b) certificate for anticorrosion tape showing the manufacturer’s name, the date and place

of manufacture and showing that the material complies with the requirements stated in the Contract and including results of tests in accordance with the Contract.


14.5 WORKMANSHIP 14.5.1 Access to pipelines

(a) Rubber wheeled trolleys shall be provided to obtain access inside pipelines exceeding DN 500 for water supply pipeworks in order to joint pipes, repair joints, coatings and linings and inspect the pipeline. Persons entering pipelines shall wear clean soft-soled footwear.

(b) Mechanical fans shall be provided to ensure that an adequate air supply is available to

those entering pipelines for inspection. Engine driven fans shall be fitted with a flexible exhaust or other methods of keeping exhaust fumes clear of the fresh air intake.

14.5.2 Laying pipes

(a) The Contractor shall notify the Project Manager before pipelaying starts in any part of the Permanent Works.

(b) The Contractor shall inspect pipes, joints, fittings and valves, including internal and

external coatings, immediately before and after pipelaying; valves shall be inspected to ensure that they are in working order and are capable of being fully opened and closed. Deleterious material shall be removed and damage shall be repaired immediately before and after pipelaying; potable water shall be used for washing.

(c) The inside of pipelines shall be kept clean and free from water, dirt, stones, debris and

deleterious material. Except when pipes are being jointed, the open ends of pipelines shall be sealed with a wooden plug or stopper.

(d) Measures shall be taken to prevent flotation of pipes.

(e) Pipelaying shall follow closely on excavation of the trench. Lengths of trench which

in the opinion of the Project Manager are excessive shall not be left open. (f) Pipelines with a gradient steeper than 1 in 20 shall be laid in an uphill direction with

sockets facing uphill. (g) Pipes shall be laid in such a manner that water will not pond in locations with either

zero or shallow gradients, and the line and level of pipes shall comply with the specified tolerances.

14.5.3 Laying pipes with flexible joints

The degree of the curve of pipes for water supply pipeworks with flexible joints which are to be laid to a curve shall be equally distributed over all joints within the curved section. The deflection at a completed joint shall not exceed 3° or three-quarters of the maximum deflection recommended by the manufacturer whichever is less.

14.5.4 Installation of valves

(a) Operating gear and associated fittings shall be installed and fixed at the same time as valves, for water supply pipework, are installed. After installation, valves shall be cleaned inside and outside and left in a closed position.


(b) Extension keys and clamps shall be fixed to valves in valve chambers if the vertical distance between the top of the valve spindle and the finished ground level exceeds 600 mm. The length of extension keys shall be such that the top of the extension key is not more than 300 mm below the finished ground level.

14.5.5 Bedding pipes

(a) Surfaces on which pipes for water supply pipeworks will be laid shall be cleaned and objects which may damage the pipes shall be removed before pipes are laid.

(b) The bottom of trenches on which pipes will be laid directly shall be shaped to support

the pipes uniformly along the length of the barrel; holes shall be dug to prevent pipes resting on the sockets and to allow the pipes to be jointed.

14.5.6 Cutting pipes

(a) Pipes for water supply pipeworks shall be cut and the ends shall be prepared in accordance with the manufacturer's recommendations. Pipes shall be cut using purpose made equipment recommended by the manufacturer and reviewed without objection by the Project Manager.

(b) Cut ends of pipes shall be square and even, without damage to the pipe or coating.

Cut ends, including cut ends of the piece not immediately required, shall be trimmed and chamfered to suit the type of joint and in such a manner that elastomeric joint rings will not be damaged by the cut end.

(c) Pipes requiring to be cut to form closing lengths shall not be cut until adjacent pipes

have been laid and jointed and the length to be cut can be accurately measured. 14.5.7 Drilling pipes

(a) Pipes for water supply pipeworks shall be drilled for small diameter connections using purpose made drilling and tapping equipment.

(b) The threads of screw joints shall be painted before assembly with two coats of

bituminous paint and shall be wrapped with three turns of spun yarn. 14.5.8 Jointing pipes

(a) Pipes for water supply pipeworks shall be jointed in accordance with the manufacturer's recommendations and using jointing equipment and jointing materials recommended by the manufacturer and reviewed without objection by the Project Manager.

(b) The Contractor shall inspect pipes, joints, fittings and valves, including internal and

external coatings, immediately before and after jointing. Deleterious material shall be removed and damage shall be repaired immediately before and after jointing; potable water shall be used for washing. Surfaces which are to be jointed and jointing materials shall be cleaned immediately before jointing.

(c) All joints in pipelines shall be watertight. (d) The widths of gaps at joints shall be in accordance with the manufacturer's

recommendations and shall be achieved by marking the outside of the pipe or by using metal feelers. The position of elastomeric joint rings shall be checked by using metal feelers after jointing.


(e) Gaps at joints in pipes shall be protected after jointing by methods reviewed without

objection by the Project Manager to prevent dirt, stones or other material entering the joint.

(f) Bolt holes in flanged joints and joints incorporating bolted components shall be

correctly orientated before the bolts are tightened. The correct size of bolts and nuts shall be used. Bolt threads shall be lubricated and bolts shall be tightened using the correct size of spanner. Bolts shall be tightened in diametrically opposite pairs working around the bolt circle until all bolts are tightened to the torque recommended by the manufacturer.

(g) Bolt holes in flanged joints shall be orientated symmetrically about the vertical

diameter with no bolt holes on the vertical diameter. Elastomeric joint rings shall be the correct size and shall not protrude into the bore of the pipe. The rings may be temporarily fixed to the face of the flange using a minimum amount of adhesive of a type recommended by the manufacturer; jointing compound or paste shall not be used.

14.5.9 DI pipes with push-in joints

DI pipes with push-in joints for water supply pipeworks shall be jointed by smearing the spigot end of the pipe with lubricant and placing the elastomeric joint ring in position inside the groove of the socket end of the laid pipe. The spigot end of the pipe shall be placed in the socket end of the laid pipe and pushed home.

14.5.10 DI pipes with mechanical joints

(a) DI pipes with mechanical joints for water supply pipeworks shall be jointed as stated in Clauses 14.5.10(b) to (d).

(b) The elastomeric joint ring and the ends of the pipe shall be smeared with lubricant

over a distance recommended by the manufacturer. (c) The gland and the elastomeric joint ring shall be placed in position on the spigot end

of the pipe. (d) The spigot end of the pipe shall be placed in the socket end of the laid pipe before the

bolts are tightened. 14.5.11 Repairs to joints, coatings and linings

(a) Joints and damage to coatings and linings of pipes, joints and fittings for water supply pipeworks shall be repaired as stated in Clauses 14.5.11 to 14.5.13.

(b) Repairs to joints, coatings and linings shall be carried out using materials of the same

type and grade as in the pipe, joint or fitting. (c) External repairs shall be completed before internal repairs are carried out. (d) Internal repairs and adjacent areas shall be washed with potable water after the repair

is complete.


14.5.12 Repairs to DI pipes with bitumen coatings

Internal and external repairs to joints and coatings of DI pipes with bitumen coatings shall be carried out using bituminous paint. The area to be repaired shall be cleaned to bare metal and dried. The area to be repaired shall be painted with bituminous paint to the same thickness as the adjacent coating; the paint shall be finished to a smooth uniform surface.

14.5.13 Internal repairs to DI pipes with cement mortar lining

(a) Internal repairs to joints and linings of DI pipes with cement mortar linings shall be carried out as stated in Clause 14.5.13(b) to (d).

(b) The area to be repaired shall be cut back to leave clean, bright metal. The area

surrounding the area to be repaired shall be wetted. (c) The cement mortar shall be worked into the area to be repaired and compacted to the

same thickness as the adjacent lining; the cement mortar shall be finished to a smooth uniform surface. The repaired area shall be cured with curing compound as stated in Clause 20.5.6.

(d) The inside of pipe sockets and the faces of flanges shall be kept free from cement

mortar.

14.5.14 Thrust and anchor blocks

(a) The bearing face, and other faces stated in the Contract, of concrete thrust and anchor blocks for water supply pipeworks shall be cast directly against undisturbed ground; the faces of excavations shall be trimmed to remove loose material before concreting. Excess excavation and working space shall be filled with concrete of the same grade as the block.

(b) Internal pressure shall not be applied to the pipeline until thrust and anchor blocks

have developed the specified grade strength. 14.5.15 Concrete bed, haunch and surround

(a) Concrete bed, haunch and surround to pipelines for water supply pipeworks shall be

constructed as stated in Clause 14.5.15(b) to (e). (b) Pipes shall be supported at the required level by Grade 20 precast concrete wedges,

blocks or cradles. One support shall be placed adjacent to each end of each pipe and the spacing between supports shall not exceed 3 m. Compressible sheeting shall be placed between the pipes and supports.

(c) Flexible joints shall be formed in concrete bed, haunch and surround at flexible joints

in pipelines. Joint filler shall be placed next to the flexible joint in the pipeline and shall extend for the complete thickness of the bed, haunch and surround.

(d) Polyethylene sheeting shall be placed on the trench bottom before concreting. (e) Concrete shall be placed evenly over the complete width of the bed and over the

complete length of the pipe being concreted up to a level of 25 mm below the underside of the pipe. Concrete shall then be placed on one side of the pipe only and worked under the pipe until the concrete spreads under the pipe. Concrete shall then be placed equally on both sides of the pipe to the specified level.


14.5.16 Tolerances : pipelines

The line and level of pipelines for water supply pipeworks shall be within 25 mm of the specified line and level.

14.6 INSPECTION, TESTING AND COMMISSIONING 14.6.1 Inspection of manufacture and testing

(a) The manufacture and testing of pipes, joints, fitting and valves for water supply pipeworks shall be inspected by an independent inspection authority reviewed without objection by the Project Manager.

(b) The inspections shall be carried out at the manufacturer's works or at other locations

stated in the Contract or directed by the Project Manager. The facilities and equipment required for inspections shall be provided by the Contractor.

14.6.2 Pipe jointing trials

(a) Trials shall be carried out to demonstrate that the pipes, joints and fittings for water supply pipeworks fit correctly.

(b) The trials shall be carried out at least 6 weeks before the materials are proposed to be

incorporated in the Permanent Works. (c) The Contractor shall notify the Project Manager before carrying out trials. (d) The Contractor shall immediately notify the Project Manager of any pipes, joints or

fittings which do not fit correctly. Modifications shall be made to pipes, joints and fittings which do not fit correctly or replacements shall be provided as directed by the Project Manager.

14.6.3 Trials for drilling and tapping

(a) Trials shall be carried out to demonstrate that the proposed equipment and methods of drilling and tapping pipes for water supply pipeworks will produce connections which comply with the specified requirements.

(b) The trials shall be carried out at least 14 days before drilling and tappingis

programmed to commence. (c) The Contractor shall notify the Project Manager before carrying out trials.

14.6.4 Polyethylene pipe manufacturing quality control

(a) For quality control on manufacturing of the pipes, the following tests listed in ISO 4427 shall be subject to inspection by the independent inspection authority:

(i) Clause 3.3; (ii) Clause 3.7 – melt flow rate test only;

(iii) Clauses 4.1 and 4.2;

(iv) Clause 5.1 – 100 hour at 20°C and 165 hour at 80°C only; and

(v) Clause 6.3(b).


(b) For quality control on manufacturing of the compression fittings, the following tests listed in ISO 14236 shall be subject to inspection by the independent inspection authority:

(i) Clause 6.1; and (ii) Clauses 8.3.4.2 and 8.3.4.3.

(c) Polyethylene materials for both PE80 and PE100 shall be tested in accordance with

the Chlorine Water Test specified in Clause 9.8 of the Japanese Industrial Standard (JIS) K6762 and the performance of the polyethylene materials shall comply with the chlorine-water resistance for single wall pipe specified in Clause 5 of the JIS K6762. Test certificates shall be submitted to the Project Manager for review.

14.6.5 Sampling polyethylene pipes

(a) Sampling procedures for inspection shall be in accordance with BS6001 : Part 1

unless specified otherwise and shall meet the following requirements: (b) Sample size for dimensional, appearance, casting quality and BS21 threading checks

on pipe materials shall be determined in accordance with BS6001 : Part 1 at Inspection Level II for single sampling plan. Materials from different sources shall be sampled as isolated batches. Normal inspection shall be used at the start of inspection. Inspection may be switched to tightened or reduced inspection and switched back to normal inspection in accordance with the procedures stipulated in Clause 9.3 of BS6001:Part 1. Acceptable Quality Level (AQL) shall be 4.0.

(c) For material and marking checks, one sample shall be selected from each type and

size of pipe materials in each batch. Materials from different sources shall be sampled as isolated batches.

14.6.6 Testing Polyethylene Pipes

(a) Water/Hydrostatic Pressure Test

(i) Notwithstanding Clause 6.1 of BS6001 : Part 1, each batch shall, as far as practicable, consist of units of pipes of a single type, grade, class and composition, of different sizes, manufactured under essentially the same conditions, and at essentially the same time. Two samples shall be selected from each size of the pipes in each batch.

(ii) Duration of tests shall be in accordance with the relevant specification. (iii) Tests shall be witnessed before any finishing treatment. (iv) Acceptance criteria shall be no failure of witnessed water/hydrostatic pressure

tests.

14.6.7 Testing Polyethylene Fittings

(a) Water/Hydrostatic Pressure Test

(i) Notwithstanding Clause 6.1 of BS6001 : Part 1, each batch shall, as far as practicable, consist of units of pipes of a single type, grade, class and composition, of different sizes, manufactured under essentially the same conditions, and at essentially the same time. Two samples shall be selected from each size of the pipes in each batch.

(ii) Duration of tests shall be in accordance with the relevant specification. (iii) Tests shall be witnessed before any finishing treatment. (iv) Acceptance criteria shall be no failure of witnessed water/hydrostatic pressure

tests.

14.6.8 Cleaning and sterilisation of pipelines

(a) Fresh water and potable water pipelines for water supply pipeworks shall be cleaned and flushed through with potable water. Cleaning and flushing shall be carried out:

(i) before and after the complete pipeline, or part thereof permitted by the Project

Manager, has been tested;

(ii) after the Temporary Works required for testing have been removed; and

(iii) after parts of the pipeline removed for testing have been reconnected.

(b) The pipeline shall be completely filled with water that has been dosed with a homogeneous solution of sterilising chemicals such that the final concentration of free chlorine in the water is at least 30 ppm. The water shall be left in the pipeline for at least 24 hours.

(c) After the 24 hour period, the pipeline shall be drained down and the sterilising water

shall be flushed out using potable water until the concentration of the remaining chlorine is less than 1 ppm.

(d) Pipelines shall be cleaned and sterilised not more than 7 days before the application

for Completion Certificate. 14.6.9 Testing: pressure pipelines for water supply pipeworks

(a) Pressure pipelines for water supply pipeworks shall be tested as stated in Clause 14.6.9(b) to (f).

(b) The pipeline shall be tested in sections as stated in the Contract unless otherwise

permitted by the Project Manager; if testing in sections other than those stated in the Contract is permitted, the section to be tested shall be as long as practicable provided that the specified test pressure will not be exceeded. Final tests on complete pipelines which have been tested in sections shall not be carried out unless stated in the Contract.

(c) The test pressure shall be as stated in the Contract. If the test pressure is not stated in

the Contract, the test pressure shall be:



(i) 1.5 times the maximum working pressure if the maximum working pressure does not exceed 1.5 Mpa; or

(ii) 1.3 times the maximum working pressure if the maximum working pressure

exceeds 1.5 MPa.

(d) Unless otherwise permitted by the Project Manager, pressure tests shall not be carried out until fill material has been deposited and compacted over the complete length of the pipeline to be tested; if permitted, sufficient fill material shall be deposited to restrain the pipeline in position during the test.

(e) Tests shall not be carried out simultaneously on pipelines in the same trench. (f) The method of testing shall be in accordance with Appendix A14.1. (g) The pipeline shall be left charged with water at a head of at least 15 m after testing

and until the pipeline has been sterilized. 14.6.10 Compliance criteria: pressure pipelines for water supply pipeworks

The results of tests on pressure pipelines for water supply pipeworks shall comply with the following requirements:

(a) the leakage of water from the pipeline determined by the pressure test shall not

exceed the permitted leakage calculated in accordance with Clause A14.1.4 in Appendix A14.1; and

(b) there shall be no discernable leakage of water from the pipeline or from any joint

during the pressure test. 14.6.11 Non-compliance: pressure pipelines for water supply pipeworks

If the result of any test on pressure pipelines for water supply pipeworks does not comply with the specified requirements for the test, the Contractor shall investigate the reason. Remedial or replacement work reviewed without objection by the Project Manager shall be carried out and the pipeline shall be retested.

14.6.12 Testing: water sterilisation

After the pressure test on fresh water and potable water pipelines have been completed, samples of the water in the pipelines shall be taken by the Contractor in the presence of the Project Manager. The number of samples and locations of sampling shall be as directed by the Project Manager. Testing shall be carried out as stated in Clauses 24.6.11 to 24.6.12 for water sterilisation of water retaining structures.


APPENDIX A14.1

PRESSURE TESTS ON PIPELINES A14.1.1 Scope This method covers the determination of the leakage of water from pipelines for water

supply pipeworks by means of a pressure test. A14.1.2 Equipment The following equipment is required:

(1) blank flanges or caps; (2) struts and wedges; (3) temporary concrete blocks or other anchors; (4) force pump and pump feed tank; (5) pressure gauge, readable and accurate to 0.01 m head; and (6) continuous pressure recorder and purpose made charts.

A14.1.3 Procedure The procedure shall be as follows:

(1) pipes and valves shall be checked for cleanliness and the operation of valves shall be checked;

(2) blank flanges or caps shall be fixed to the ends of the pipeline, or section of the

pipeline, to be tested. Tests shall not be made against valve gates; (3) the blank flanges and caps shall be secured with struts and wedges against temporary

concrete blocks or other anchors. The blocks and anchors shall be completed and shall have hardened sufficiently before testing starts;

(4) thrust and anchor blocks, pipe straps and other devices required to prevent movement

of pipes and fittings shall be completed before testing starts; (5) the pipeline shall be filled with water and all air shall be removed; (6) the pipeline shall remain filled for 3 days before testing starts to allow absorption to

take place and to achieve conditions which are as stable as practicable; (7) the pressure in the pipeline shall be increased slowly to the specified test pressure by

pumping water into the pipeline using a force pump; (8) the pressure in the pipeline shall be maintained within +0% and -5% of the specified

test pressure for a test period of at least 2 hours; (9) at the beginning and end of the test period and at 30 minute intervals during the test

period, readings shall be taken from the pressure gauge and the pressures (p) shall be recorded. The pressure shall be adjusted to the specified test pressure each time a reading is taken;


(10) the pressure shall be adjusted to within the specified tolerances for the test pressure at any time during the test period if the pressure falls outside the specified tolerances;

(11) the pressure shall be monitored during the test by means of a continuous pressure

recorder with purpose made charts; and (12) the leakage of water from the pipeline shall be measured as the amount of water

required to maintain the specified test pressure in the pipeline; the amount of water shall be determined from the fall in level of water in the pump feed tank.

A14.1.4 Calculation

(1) The average test pressure (P) shall be calculated as the average of the pressures (p) recorded during the test.

(2) The permitted leakage of water from the pipeline during the pressure test shall be

calculated from the equation: t P

Permitted leakage = 0.02 x d x l x x litre 24 10 where:

- d is the nominal diameter of the pipe (mm) - l is the length of pipeline tested (km) - t is the test period (hr) - P is the average test pressure (m)

A14.1.5 Reporting of results

The following shall be reported: (1) the internal diameter of the pipe to the nearest 1 mm; (2) the length of pipeline tested to the nearest 1 m; (3) the test period to the nearest 0.01 hr; (4) the pressures recorded during the test to the nearest 0.01 m; (5) the average test pressure to the nearest 0.01 m; (6) the leakage and permitted leakage of water to the nearest 0.1 litre; (7) details of any discernable leakage of water from the pipeline during the test;

(8) charts obtained from the continuous pressure recorder; and

(9) that the test method used was in accordance with this General Materials and Workmanship Specification.

civil engineering works...issue no. 4: january 2004 (i) general materials & workmanship...

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