ANNEX A - ARCHITECTURAL SERVICES WORKS AppendiANNEX A - ARCHITECTURAL SERVICES WORKS ... CONQUAS 21 series. These booklets are available for purchase from the BCA

Download ANNEX A - ARCHITECTURAL  SERVICES WORKS  AppendiANNEX A - ARCHITECTURAL  SERVICES WORKS ... CONQUAS 21 series. These booklets are available for purchase from the BCA

Post on 17-Feb-2018

215 views

Category:

Documents

3 download

TRANSCRIPT

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P1 - 1 -1

    ANNEX A - ARCHITECTURAL & SERVICES WORKS General Notes: The Contractor is required to include in his tender this and all other general specification of works or descriptions as detailed in the Consultants drawings and Breakdown Schedule as accepted and expected of them by the respective trades and profession. All other works (including ancillary works) that are required to see to the successful completion of the project to CSC are deemed to be inclusive in the contract as quoted in the tender and contract price. The Contractor is deemed to have inspected the site and documents and is satisfied that the works as described in the tender, documents and contract drawings are sufficient, complete and clear enough for the Contractor to understand and construct the project to completion with CSC. Should the Contractor require any additional items or information, these should be asked or informed before the contract is executed between the Contractor and the Company. Under no circumstances will the Company and or the Consultants entertain any claims for extra time or cost due to plead of ignorance or misunderstood interpretation of the documents and drawings. It is agreed by the Contractor that the Consultants assessment and directions in all matters arising out of such are final and non-negotiable. Should there be a discrepancy, omission, typographical error or duplication of items resulting in a reduction in cost, this cost is allowed by the Contractor to be omitted, deducted or adjusted from the contract sum in the final accounts leading up to the Companys acceptance of the project. Should there be an addition, discrepancy or typographical error or addition of items resulting in an increase in cost, the Contract sum cannot be adjusted by the Contractor and is treated as absorbed or included in the first instance when the contract is signed. The above is excluding any direction, instructions, or amendments issued by the Company and or the Consultants during the course of the project as determined by the Consultants to be or could be varied. In case of doubt, the Contractor is to seek clarification from the Consultants. This specification may carry some items that is not required in the works as described and should be ignored. Only relevant specification is to be referred to.

    I PART 1 - GENERAL PRELIMINARIES A. SITE PROGRAMME The Contractor is to prepare and submit to the Consultant a detailed time schedule he proposes to execute the

    whole of the Works and to sign it as part of the contract documents. The Contractor is to allow for providing all necessary additional copies of the agreed schedule.

    B. SITE MANAGEMENT The Contractor is to allow in his prices for all on and off site management cost including an air-conditioned site

    container office where weekly site meetings can be held. C. LABOUR The Contractor is to allow in his prices for the following items: -

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P2 - 2 -2

    1) Importation of labour including higher rates of wages, transport, travelling time, fares, subsistence and

    lodging allowances. 2) Operation of incentive schemes and costs of overtime working. 3) Guaranteed time. 4) Insurance and pensions. 5) Annual and Public Holidays. 6) Sick pay. 7) Any other disbursements and added requirements to comply with Labour Ministry, Union and other authority

    organizations arising from employment of labour. D. SAFETY, HEALTH AND WELFARE The Contractor is to provide suitable safety, health and welfare measures and amenities to comply with the current

    Statutory Regulations for the Building Industry. The Contractor shall be responsible for the health and safety of his own and of Sub-Contractors personnel and

    must ensure that they conduct themselves in a reasonable and safe manner consistent with the prevention of injury to persons or damage to property. The Contractor in this regard must conduct induction classes to all workers entering the Site.

    The Contractor must observe all statutory regulations and codes of practice applicable to his and to Sub-

    Contractors personnel and to the work covered by the contract and must also observe any special safety requirements notified to him by the Consultant.

    The Contractor must nominate a member of his staff (Safety Officer) to deal with safety matters and inform the

    Employer/Consultant of the name and mobile phone number of his nominee. The Safety Officer must be contactable 24 hours/ 7 days and conduct inspections as required by him under the statutory requirements.

    The Employer will inform the Contractors Safety Officer of any special safety procedures in force and he will then

    be responsible for training all the of the Contractors personnel on the procedures. E. USE OF EXISTING TOILETS, WATER & POWER The Contractor will arrange his own temporary toilet facilities for all workers on site to use freely. Temporary

    supplies and cleaning of the toilets for cleanliness and health requirements must be arranged and paid for by the Contractor.

    The Contractor can separately arrange with the Employer (if allowed) for the use of toilet facilities, water and

    electricity power and will be responsible for any damage, cleanliness arising out of such usage. The Employer reserves the right to charge or refuse the use of Employers toilets, supply of water and power. F. SECURITY The Contractors attention is drawn to the fact that the Employer reserves the right to implement the following

    security measures: - a) The Employer reserves the right to search any vehicle, person or property, entering, leaving or present on the

    Employers premises.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P3 - 3 -3

    b) The Contractor shall at the reasonable request of the Employers Company Security Officer produce for his immediate inspection a list showing the full names, NRIC No., home addresses, date of birth and occupation of each of his employees working on Company property. The Contractor shall be responsible for ensuring that his Sub-Contractors are aware of and will comply with these requirements. Security passes will be issued and worn at all times on site and within the Airport Restricted Areas. Workers without security passes will not be allowed into the Airport security area.

    G. MATERIALS, GOODS AND WORKMANSHIP All materials, goods and workmanship shall be of the best quality of their respective kinds and trade. Consultants

    assessment of the quality and defect or acceptance will be final. All materials and goods shall be used or fixed strictly in accordance with the manufacturers printed instructions and

    recommendations. The Contractor is deemed to comply with all good trade and industry practices as published by the BCA under the

    CONQUAS 21 series. These booklets are available for purchase from the BCA should it be required by the Contractor and is not reproduced here. Should there be works that are not reflected or specified, the Consultants direction, instruction or determination will take precedence and the Contractor must abide by it. The Consultant in his determination of the unspecified works will be fair in his judgment and provide for any variation to time, or cost as deemed fair.

    H. PLANT, TOOLS AND VEHICLES Provide all necessary plant, tools and vehicles for the proper execution of the Works in the agreed period of time for

    completion of this Contract. The Contractors attention is particularly drawn to the prevention of nuisance to the Employer and adjoining owners

    and occupiers from the carrying out of the Works as previously described under the item head Adjoining Property and Prevention of Nuisance.

    I. GENERAL SCAFFOLDING, CRANE, LIFTING EQUIPMENT & GONDOLA SYSTEM Provide all necessary general scaffolding, Crane, Lifting Equipment & Gondola for the proper execution of the

    Work. Metal scaffolding is preferred to bakau scaffolding, and all such works, including gondola, must be with Contractors PE approval and endorsement and approved by the authority for use.

    J. SAFEGUARDING THE WORKS Safeguard the Works, materials and plant against damage and theft including all necessary storage, watching and

    lighting for the security of the Works. The Employer does not provide any safe storage facility and all stores are to be within the work site without obstructing or inconvenience Employers areas or use.

    K. MAINTENANCE OF ROADS, ETC. The Contractor is to make good at his own expense any damage to roads, bridges, footpaths, rights-of-way, grass

    and landscape etc. (including services, drains and sewers). A pre-condition survey by the Contractor is required to establish existing condition of site and surrounding to avoid claims of damage and responsibility.

    L. MAINTENANCE OF SERVICES Protect, uphold and maintain public and private services, drains, Cables and sewers and give all necessary notice

    to the local authority, SATS, CAG or other statutory undertakers about the works to be done over, around and under it. The Contractor is responsible to protect (temporarily or permanently), carry out any works required to help maintain such services during and after construction.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P4 - 4 -4

    The Contractor is to make good at his own expense any damage to public and private services, drains and sewers caused by the carrying out of the Works provided such damage is due to any negligence, omission or default of the Contractor (or his Sub-Contractor).

    M. MAINTENANCE OF EXISTING BUILDING, ETC. Protect and uphold the existing buildings on the site and the adjoining buildings during the period of this Contract. The Contractor is to make good at his own expense any damage to the existing buildings, fences etc on or around

    the site and any adjoining buildings/property. N. WATER FOR THE WORKS The Contractor will arrange with the building owners or Employer for the use of the water at site. The location point

    of the supply will be as advised. The Contractor is to make all necessary temporary arrangements for the distribution from that point. Charges by the Employer for the use of water may apply.

    O. LIGHTING AND POWER FOR THE WORKS Provide lighting and power for the Works and make all temporary arrangements for distribution about the site. A

    separate Contractors Site Distribution Board (PE Certified) is required to be fitted for this distribution. The Contractor can alternatively arrange with the building owner or Employer for the use of the above. The location

    point of the supply will be as advised. Charges by the Employer for the use of electrical services may apply. P. P.C. SUMS If the Contractor is permitted to tender (and his tender is accepted) for any work, materials or goods for which a P.

    C. Sums has been included in the document, such P. C. Sum together with profit (if any) which has been added by the Contractor will be omitted. Any profit and attendance (P&A) required by the Contractor shall be included in his tender for the work covered by such P.C. Sums. If none stated, it will be deemed that no P&A cost is charged by the Contractor.

    Q. SUB-CONTRACTORS, LOCAL AUTHORITIES, STATUTORY

    UNDERTAKERS AND FIRMS EMPLOYED DIRECT It is deemed that the following attendance is required of the Contractor which is deemed inclusive in his tender. a) General Attendance General attendance on nominated sub-contractors, local authorities, statutory undertakers and firms employed

    directly shall be deemed to include allowing reasonable and free use of standing scaffolding, rooms, sanitary accommodation and welfare facilities, providing space for office accommodation and for storage of plant and materials, providing light and water for their work and clearing away rubbish.

    b) Special Attendance Special attendance on nominated sub-contractors shall be deemed to include unloading and distributing the

    sub-contractors materials and plant, providing light to the nominated sub-contractors office and storage area and providing power for tools, etc.

    c) Additional Items for Attendance Additional items for attendance on nominated sub-contractors, where applicable, have been described

    separately in this document.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P5 - 5 -5

    d) Particulars of Requirements The Contractor is to obtain from sub-contractors, local authorities, statutory undertakers and firms employed

    direct full particulars of their requirements with regard to holes, chases, recesses and other details and is to supply them with all necessary dimensions and other information to enable their work to be correctly executed and subsequent alteration obviated.

    If the Contractor strikes/remove scaffolding before ascertaining whether it is required by any sub-contractor,

    local authority, statutory undertaker or firm employed directly, he will be responsible for re-erecting the scaffolding if so required at his own expense.

    e) Damage to Works It is the responsibility of the Contractor that the work of any sub-contractor, local authority or statutory

    undertaker employed by him under this Contract is not damaged by another or by himself and will be required to make good any such damage at his own expense and to the satisfaction of the Consultant.

    R. PHOTOGRAPHS The Contractor shall not take or permit to take any photographs on site without the written consent of the Employer.

    No photographs so taken shall be used for publicity purposes without the written consent of the Employer. Progress photographs before, during and after construction must be provided, if requested. Cost of same is

    considered inclusive in the tender. S. TEMPORARY HOARDING, FENCE AND GANTRIES The Contractor is to allow for providing all temporary hoarding, fenced & planked footways, guard rails, gantries and

    the like as may be necessary for protecting the public and the adjoining owners/occupiers, for meeting the requirements of any local or other authority and for the proper execution of the works and pay all charges in connection therewith.

    Any hoarding erected is to be painted externally with 2 costs of oil paint of a colour approved by the Consultant.

    Polykem finish boards are also allowed. No advertisements will be permitted on any hoarding, fan, guard rail, gantry, etc. except safety signs and We are

    moving with you and We are Building to serve you better. These signs will be deemed inclusive. T. NAME BOARD A site notice board is left to the Contractors proposal and will follow the BCAs requirements in size etc as specified

    ( if stated ) but the letter, details and positions must all be agreed with the Consultant prior to the erection and the Contractor must pay for all costs incurred and deemed inclusive in the tender. SATS Logo/CAG/CAAS logo is to be inclusive.

    No other advertisement or trade signs will be permitted on the site unless approved by the Employer/Consultant. U. PROTECTING, DRYING AND CLEANING THE WORKS The Contractor is to maintain, whenever practicable, continuity of working and productivity during inclement

    weather. Provide all temporary screening to openings, etc. required for drying and controlling the humidity of the Works in an

    efficient manner and at own costs.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P6 - 6 -6

    Remove all rubbish and debris, clean the Works internally and externally and hand over the whole of the Works in a clean condition to the approval of the Employer.

    V. SUBSTITUTIONS If the Contractor wishes to substitute materials or goods he must obtain the Consultants written approval before

    proceeding. It is recommended that if the Contractor wishes to make any substitutions, then he should do so when tendering for

    the project. Samples, brochures, details, etc., are to be submitted with the tender if the Tenderers are providing an equivalent or

    substitute material. W. NOTE REGARDING PROPRIETARY NAMES Whenever a proprietary name is used in any of the Contract Documents it is used to denote the particular standard,

    specification, performance, finish and appearance of the product to which it refers and it is deemed to include. Other equal or superior products may be substituted providing they match or improve upon all named products and

    are approved by the Designer. Samples, specifications, brochures are to be submitted together with this tender if the Tenderer proposes to do so.

    II. PART 2 - MATERIALS AND WORKMANSHIP SPECIFICATIONS This specification is divided into the following sections: - 1.1 PARTITIONS, JOINERY & FURNITURE CONSTRUCTION a) Timber All approved HW (as schedules and samples) carcass timber to be seasoned to within 2% of the relative

    humidity of the interior space in which it is being used. No dead knots, cup or stair shakes, or other splits allowed to face timber. No insect infected timber allowed for face or carcass work. Sheet materials - Plywoods, laminated board and chipboard All plywoods to be HW construction with waterproof adhesive bonding. Surface for fairface finishing. All laminated boards to have HW constructional veneers and waterproof adhesive bonding. Surfaces for

    fairface finishing. Clipboard shall be of a thickness and density suitable for use for flat panels of domestic furniture (e.g. Wyeroc

    600 density or similar approved). Plywood shall be MR bonding grade 2 veneer or of equivalent type and grading. Manufacture must be by the dry cementing process. Plywood manufactured by the wet or semi-dry method shall not be used.

    Veneers, Laminated Plastics and Mirror. b) Veneers

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P7 - 7 -7

    All veneers to be selected and approved prior to application. No veneers for face work to be filled or pleated. Clean splits allowed if paper taped prior to application. Surface of the face veneers to be dampened and fine sanded prior to application of finishes. c) Laminated Plastics Plastic laminate shall be 1.5mm, construction in melamine resin/paper furniture grade. The laminate shall be

    uniform in colour and free from cracked edges or damage or imperfection of any kind. Balancing veneers to be applied only to faces, which are to remain permanently concealed may be of a cheaper quality balancer but shall be compatible with the decorative finish, and obtained from the same supplier. Veneers, plastic laminate where specified shall be applied to both faces of panels, glued and pressed to cores to ensure firm and even overall adhesion. Laminate shall be carried over edging, brought flush with face of edging and then finished with slight chamfer. Panels shall be faced on each side with a single sheet of laminate without intermediate joints. Finished faces shall be flat and true, free from warping, waving, high or low spots. Where an entire panel face is to remain concealed, this face shall have a balancing veneer as described previously and applied in the same manner as set out above. The grain shall be straight and matching panels/components must have an equal number of leaves. Each leaf to be of the same width with alternate leaves turned and matched exactly.

    Veneers shall be totally bonded to the core material, and care must be taken to ensure that there are no loose

    areas or edges. But joints between leaves must not show and the only evidence that a veneered surface consists of more than one leaf shall be the figure and matching of veneers. Veneer joints shall be parallel to the edges of panels/components. All surfaces shall be thoroughly sanded and free from defects of every description including tape, if used for jointing veneers, sanding marks, adhesive, etc. Care must be taken not to sand through the veneer thickness. Edges must be thoroughly sanded and not show machine marks nor other defects and the standard of finish shall be the same as flat surfaces.

    All cores to panels/components shall be solid and of the same material throughout which shall be of MDG

    chipboard or plywood. Cores shall be in one peace in any one panel. All cores shall be edged all round with hardwood to form exposed profiles of panels.

    Tongues between edging and cores may be considered as optional; of the Contractor undertakes to provide

    equally storing glued joints. Lipping shall be applied with adhesive not panel pins and sanded flush with core material before veneering.

    Exposed corners shall be mitered very precisely. When panels/components are seen in close relationship, the colour and grain characteristics of the veneers

    must be consistent. Veneers selected for inside surfaces must not be of an inferior quality. d) Mirror Mirrors are to be 6mm silvered glass cut to size as indicated and polished on all edges unless dimensioned as

    thicker on drawings. e) Diamond Mirror 3mm or 4mm selected glass, silvered, coppered and laminated with FR grade foam interlayer to a rigid

    aluminium-skinned foam board. f) Storage Store on edge protecting the boards edge from mechanical damage. The isocyanurate board is supplied

    oversized and trimmed off with a knife before installation. This protects the edge of the mirror in transit.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P8 - 8 -8

    g) Joints All joints shall be properly made and accurately machined to give a perfect fit without gaps between shoulders

    of the joints and abutting surfaces. All joints are to be glued properly under pressure with the best quality glues of the appropriate type. Open joints disguised with filler will not be accepted.

    The Contractor shall be responsible for the sound construction of all components using recognized forms of

    joints in appropriate positions. This specification and the drawings listed on the drawing schedule do not show all methods.

    All mortise and tenon joints to be 1/3 / 1/2 proportion and to have HW fox-tailed wedges, haunched where

    necessary. Glue grooved HW dowels with rounded ends to be used. Plywood loose tongues to be in HW laminated construction with waterproof adhesive (not to exceed of the

    total interface width). Edge Lippings & Table Tops Edge lippings to be flush with top face surface and have external arises rounded. Corner and inter edge joints

    dowelled, with mitres at right-angled junctions. Carcass Work and Shelves Veneers carried over edge lippings (lippings applied and cured prior to veneering) no end grain to be

    revealed. All joints to be degressed with carbon tetrachloride prior to application of adhesive. All surplus adhesive to be removed from joints at time of assembly, prior to curing. Grounds for veneers and laminate plastics to be roughened up prior to application. h) Adhesives Urea-formaldehyde for all joints and for laminate plastics and veneers to grounds (with platten press). i) Finishes to Timber and Veneers All stained and ebonized finished to be spirit-based and applied to application of general finishes. Samples

    required for approval. General Finishes 3 coats polyurethane lacquer, cut down between coats 1 and 2, and 2 and 3 with fine wire wool matt finish.

    Application to be in accordance with manufacturers instructions. All planner marks to be sanded out, timber and veneers to be left with a fine sanded finish prior to application

    of finishes. Do not scale drawings. If in doubt, ask. Construction can be varied only in consultation with Designers.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P9 - 9 -9

    Setting out rods to be approved and prototype submitted prior to manufacture of batches. j) Gypsum Partitions All partitions are to be fixed firmly to ceiling channels and on floor with positive non-corrosive screws and in

    construction and thickness typical of same. All studs are to be 600 c/w vertically and with horizontal bracing when required. Horizontal timber piece

    throughout gypsum partition at 1700 high for handing of pictures, etc. must be put up. As and when specified or shown in drawing, gypsum partitions are to be timber framed reinforced, where there

    are wall hang on components. Otherwise, all gypsum is to be constructed in non-combustible framing. All plaster boards or gypsum boards are to be butt jointed, crossed lined, filled and rubbed down and screw

    fixed. Junctions with existing walls, sills, window frames, mullions and window heads to be carried out with spaced

    scribing piece edge with soft gasket such as neoprene. All gypsum partitions are to be properly plastered and levelled to receive wallpaper or painting or painting

    works. All gypsum edging and corners are to be protected with 12mm wide aluminium angle. All markings on gypsum bard are to be removed or sealed over with sealer paint if it is determined that the

    markings may affect painting or wallpapering works. For partitions specified to have 50mm fibre glass insulation, sandwich between the gypsum boards,

    partitioning works should be from floor to underside of slab. Contractors are to note that all partitioning works are to be lined and plumb and inspected by the

    Consultant/Designer before construction. 1.2 PAINTING & DECORATING a) Paints Generally All materials for painters works shall be of the best grade and obtained from an approved manufacturer.

    The Painters materials shall be used strictly in accordance with the manufacturers printed instructions. Materials shall be delivered to the site in their original sealed and branded containers. The mixing of materials of different brands before or during application will not be permitted. Brushes, pails, kettles and other implements or tools used in painting and preparation of works shall be clean and free from foreign matters. They shall also be thoroughly cleaned before being used for different types of classes of material or colours.

    b) Priming Generally A priming coat of appropriate type and quality for the surface concerned shall be applied to all surfaces,

    after initial preparation as described under workmanship clauses has been completed. c) Priming on Metal Galvanized metalwork shall be primed with calcium plumbate primer.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P10 - 10 -10

    d) Priming on Wood Woodwork shall be primed with an approved aluminium wood priming paint. Priming of joinery shall be

    applied on site after the Interior Designer has approved such joinery before it is fixed. Prime backs of all frames and other joinery, which will be hidden in the work.

    e) Knotting Knotting shall mean the application of two coats of best quality Shellac Knotting to BS 1336. f) Stopping Stopping shall be with approved filler used strictly in accordance with the manufacturers instruction. g) Oil Paints The paints for undercoats and finishing coats on metal and wood shall be ready mixed alkyd resin based

    paint. The paint for finishing coat shall be wither satin finish of full gloss finish, as shown on Particular Specification.

    h) Lacquer The clear and colored lacquer shall be polyurethane non-tinted or tined lacquer of best quality obtained from

    an approved manufacturer. i) Workmanship Preparation of Work Area Before the commencement of and during the painting and decoration work or the preparation of it, every

    possible precaution shall be taken by the Contractor to keep down dust, including vacuum cleaning each room before hand, and if necessary and approved by the Consultant, the dampening of floors. No paint of any kind shall be applied to works which are damp, and all surfaces shall be freed of all loose matter, efflorescence of salts, dust, etc., and treated with non-dusting compound before the application of paint. Pre-primed, primed or undercoated work shall not be left exposed or in an unsuitable condition for an undue period before completion of the painting process. Metal or other fittings such as ironmongary, etc. not required to be painted shall first be fitted and then removed before the preparatory process is commenced. When all painting has been completed, the fittings shall be cleaned and re-fixed in position. Paints shall be stirred in their original container until smooth before use and thinning or dilution of paints shall be in strict accordance with the recommendations of the manufacturer in each case. The first set of brush strokes for any coats shall be finished with a light stroke either vertical or parallel to the grain in the case of timber.

    j) Preparation of Surfaces All surfaces to be painted shall be properly prepared in accordance with the manufacturers

    recommendations. Plastered and plain-face surfaces shall have all cracks and other defects cut out and filled with hard plaster, the filling shall be struck off level with the surrounding surface and allowed to dry out thoroughly. Metal work shall have all rust scale and grease removed with a wire brush. Metal work delivered to the site primed is to be thoroughly inspected when received on site and all unsatisfactory priming removed and the surface prepared and rimed. All blemishes shall be rubbed down and all pits filled. Damaged priming is to be touched up after preparation. Wood surfaces shall be cleaned off and rubbed smooth and even with fine glass paper. The preparation of wood surfaces shall include for stopping and filling as described and as directed by the Designer, and for rubbing down and bringing to a smooth surface. Plastered surfaces shall be allowed to thoroughly dry out before paint is applied. All coats shall thoroughly dry before subsequent coats are applied.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P11 - 11 -11

    k) Colours All tints of paint or other decorative material shall be selected and approved by the Consultant and each

    coat shall all differ noticeably from the subsequent coat. l) Covering Capacity The Contractor must satisfy himself as to the covering capacity of all paints according to the absorption of

    the varying surfaces and should allow in his prices accordingly. m) Application of Paints The application of paints must be sufficient to give solid colour in the number of coats specified. All surfaces

    shall be cleaned, free from all dirt, grease, oil or other deleterious matter. No paint shall be applied to damp surfaces. All coats of paint must be thoroughly dry before subsequent coats are applied, and rubbed down with fine waterproof abrasive where necessary.

    n) Painting of Metal Prepare as described, prime with the appropriate primer and paint two undercoats and one finishing coat of

    gloss paint on metal internally and externally. o) Oil Paints Oil paints shall be applied on to prepared and primed surfaces with two undercoats and one finishing coat. p) Polyurethane Lacquer The polyurethane lacquer to wood surfaces shall be applied in three coats strictly in accordance with the

    manufacturers instructions. Lacquer applied to large surfaces such as door faces edges, etc. should be sprayed in a spray booth,

    offsite, by a specialist and sanded down and polished to a final thickness of 1mm. Only the highest quality furniture standard lacquer work will be accepted. The Contractor must allow for all surfaces, internal and external, to be lacquered, if lacquer work is referred on drawings, in his costing. Difficult areas to spray, sand and polish must be brought to the attention of the Designer before commencement of work. Samples of lacquer work must be supplied to the Consultant to establish a standard.

    q) Cover Up and Protection Cover up all floors, fittings, etc., with dust sheets before executing any painting work. Paint splashes, spots

    and stains shall be removed from floors, woodwork, glass, etc., all damaged work shall touched up and the whole of the work left clean and perfect on completion. Cover up and protect all finished painting and decoration after completion of the work and make good any damage done by following trades such as carpet layers, curtain hangers, furniture installers, etc.

    1.3 WALLS & WALL FINISHES Examine all surfaces to receive wall covering and report to the Consultant in writing, on conditions that would

    detract from a perfect installation. a) Workmanship

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P12 - 12 -12

    Installation shall be made by a Contractor whose operatives are fully trained to perform the work in a neat and workman like manner. All seams must be tightly and neatly butted. All air pockets and bubbles eliminated and there must be a firm bond of all the wall-covering to the under-laying surfaces on all the wall areas. Seams must be made at least four inches from the inside, the outside corners and horizontal seams will not be accepted. Wall-covering surfaces shall be cleaned as the work progresses and all paste residues must be removed.

    b) Hanging Instruction Hanging instruction must be obtained from manufacturers for each wall covering type and are to b used to

    form the specification for each specific wall-covering application. c) Adhesive Only the manufacturers recommended adhesive to be used. d) Bricks Shall be solid, even shape, well burnt and complying to SS 103 with min compressive strength 20MN/m2 Bricks use for external walls must not have hairline cracks on the surface. e) Concrete Blocks Load Bearing Blocks shall be even in shape, square, well matured and dense that is of Class A with

    minimum compressive strength of not less than 5.6MN/m2 complying to SS 76(M) Non Load Bearing Blocks shall comply with SS 271 with minimum compressive strength of 3.2MN/m2 f) Damp Proof Course Shall be bitumen or equivalent proprietary sheets or membrane complying with BS 6398 Class B. Must be provided and laid continuously without any break at all walls in direct contact with the ground. g) Mortar Shall be Portland Cement with cement complying with SS 26. Only river sand is used for mortar mix.

    Mix ratio of 1:6 by volume for internal walls and 1:3 for external walls. Use plasticiser as recommended by manufacturers.

    External mortar to include waterproof additive of Elastiment Superior Additive 200. h) Bonding, Holdfast and re-enforcements. Generally in stretcher bond unless fair faced finish, of which direction from Consultants is required. Provide all accessories as required like holdfasts, mesh etc for holding the mortar or plastering. Should reinforced brick or blockwork be required, to provide mesh reinforcement at every 4th course. i. Wall Stiffeners Provide wall stiffeners where required and specified by Structural Engineer.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P13 - 13 -13

    1.4 TEXTILE FLOOR COVERING General a) Scope of Contract The work comprised the supplying, making up, laying and fixing in all respects of textile floor coverings. b) Samples The Contractor will be required to supply a minimum 1m2 sample of each material type in each selected

    colour and or pattern. The Contractor will also be required to supply samples for each type of carpet, including seaming, cutting

    and fitting to floor services and carpet skirtings, if any. These samples should show perfect matching. The samples should be approved by the Consultant and serve as a standard for finish accuracy. c) Planning Drawings All plans showing widths and methods of laying in all areas are required to be approved by the Consultant

    prior to the commencement of work. The Contractor can be provided with copy negatives of the floor plans to assist his work, if these are

    required. d) Protection of Materials The protection of all materials shall be the Contractors responsibility. No damaged materials are to be

    installed. Any damaged or faulty material is to be replaced at no additional charge. e) Co-ordination of Other Trades Co-ordination with other trades is necessary to ensure that materials may be properly installed and

    substantially fixed true and level, shall be the Contractors responsibility. f) Maintenance Recommendations Supply for Employers use, duplicate copies of manufacturers instructions for short and long term cleaning

    and maintenance of all material installed. If these are at variance with the accompanying maintenance manual.

    g) Material Widths The planning should be based on the use of widest possible widths handle-able to suit area sizes with the

    minimum amount of seaming. Access to the spaces must be taken into account. h) Preparation of Sub-Floor The sub-floor shall be prepared in the following manner: - Any highs spots shall be ground down to provide a totally flat and level surface for acceptance of Textile

    Floor covering. If the high area is too large to grind down, it shall be ramped by use of latex levelling compound.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P14 - 14 -14

    Any hollows or concave damages shall be filled to finished floor level by use of latex levelling compound. Where the floor is exceptionally dusty or if direct bonding installation is required, the floor shall be sealed by

    use of manufacturers recommended sealant. If the sub-floor should be either too hard or too soft to accept the standard concrete nail supplied with

    tackless gripper, the floor shall be drilled and plugged so that the gripper may be screw fixed. i) Installation No damaged materials are to be installed. Any damaged or faulty material is to be replaced at no additional

    charge. Co-ordination with other trades as necessary to ensure that materials may be properly installed and

    substantially fixed true and level. The planning should be based on the use of widest possible widths handle-able to suit area sizes with the

    minimum amount of seaming. Access to the spaces must be taken into account. The textile floor covering should be installed flat and taut enough to ensure that traffic and the movement of

    furniture over its surface does not cause rocking to take place. Direction of seams to be agreed with Consultant.

    All seams to be heat seamed. All joints to be strong enough to permit the textile floor covering to be

    stretched and not break down under traffic. Where applicable, pattern is to match and the pile lay is to be in the same direction, the pile must not be caught in the seam and the seam must lay as flat as possible. All seams to lay straight.

    Cross seams will not be accepted. All plans showing widths and methods of laying in all areas are required to be approved by the Designer

    prior to the commencement of work. Plans to assist his work, if these are required. Carpet to be installed over a fire-retardant treated 40 oz. yd. 2 weight hairs and jute under felt held at the

    perimeters and all opening on tackless grippers. j) Floor Service Access Allowance should be made for cutting and fitting to service access boxes. These boxes to be supplied and

    suitable adjusted by other. No carpet edging nor fixings to be visible. k) Completion The whole working area should be cleared of tools, waste, etc., and the job examined for lumps and

    tightness, and rectification made where necessary. All stay tacks to be removed and complete carpet area hovered.

    l) Guarantees Guarantee of materials and workmanship.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P15 - 15 -15

    The Contractor will be required to give a guarantee of a minimum of 5 years for the textile floor covering structure, yarn, underlay and or secondary back, workmanship and all proprietary equipment and materials used in the installation. The Contractor will also be required to give a guarantee that no racking or expansion will take place to cause folds, either in the cloth or at the seams, after the initial laying time.

    m) Defective Work Should any defects occur with the Defects Liability Period, such defective work shall be removed and

    renewed to the Designers satisfaction and any work disturbed as a consequence shall be made good at the carpet Contractors expense.

    n) Space An additional margin of 2% (of gross carpet area) of the same quality, colour, batch and pattern to those

    installed and the spare carpet shall be delivered and hand free to charge to the Employer. 1.5 WINDOW BLINDS a) Scope of Contract The work comprises of the supplying, making up, installing and fixing in all respect of vertical louvered

    window blinds. b) Planning Drawings All plans indicating the widths and positions of blinds are required to be approved by the Consultant prior to

    the commencement of work. The Contractor can be provided with copy of negatives of the floor plans to assist his work, if these are

    required. c) Protection of Materials No damaged materials are to be installed. Any damaged or faulty material is to be replaced at no additional

    charge. d) Co-ordination of Other Trades Co-ordination with other trades is necessary to ensure that materials may be properly installed and

    substantially true and level. e) Maintenance Recommendations Supply for Employers use, duplicate copies of manufacturers instruction for short and long term cleaning

    and maintenance of all materials installed. 1.6 GLAZER a) Glass Submit samples not less than 150mm square of the various types of glass and obtain approval before

    cutting panes. All glass shall comply with BS 952 and shall be of accurate size with clean undamaged edges and surfaces,

    which are not disfigured.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P16 - 16 -16

    Toughened glass and laminated glass shall be manufactured to precise glazing sizes and with a permanent identification mark in a position, which is visible but not prominent after fixing.

    Mirror glass shall have a copper backing over the silver as well as the protective paint coating together with

    an additional backing of aluminium foil. Louvre blades shall have edges truly parallel and ground to remove sharp arises. b) Glazing Compound and Accessories Glazing compounds, including putties, shall be of a type recommended by the window and glass

    manufacturers and suitable for tropical use. Distance pieces and location blocks shall be of PVC with a thickness equal to the specified space between

    glass and bead and of a depth to give not less than 6mm cover of sealant. Setting block shall be of lead, sealed hardwood or nylon. Sleeves and washers for fixing mirrors shall be polyethylene. c) Glazing Generally Glazing shall be carried out in accordance with CP 152. Ensure that rebates are dry and clean and have been primed or sealed as required. Setting and location blocks shall be used in panes of ordinary glazing over 0.2m2 and with all sizes of

    laminated glass, toughened glass and factory made double-glazing units. Distance pieces shall be provided to all panes where a non-setting compound is used and they shall not be

    located coincident with setting and location blocks. In laminated and toughened glazing or with factory made double-glazing units the positions and sizes shall be as recommended by the glass or unit manufacturer.

    d) Compound Glazing Glazing in compound or putty shall be executed with proper bed and back putties, sprigs, clips and splayed

    and mitired front putties. The back putties shall be trimmed off flush with the tops of the rebates and the splayed front putties shall be trimmed off flush with the tops of the rebates and the splayed front putties shall be finished 3mm back from sight lines to allow for scaling between glass and putty with paint.

    e) Bead Glazing Take out beads which have been loosely pinned in by the surround manufacturer, ease and re-fix timber

    ones with countersunk brass cups and screws or rust-proofed panel pins at an adequate number of points to prevent flexing or movement.

    Glaze external glass with beads and compound. There shall be a 3mm bed of compound both sides of and

    around the glass. Glaze internal glass with beads and glazing tape. Glazing tape shall pass round both sides of the glass, be

    mitired at corners, and trimmed off flush with the beads and rebates. f) Gasket Glazing

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P17 - 17 -17

    Ensure that surfaces to which the gaskets will be fixed are free from dirt, grease, burrs, weld spatter, other projections and are smooth and undisturbed.

    g) Silicon joints and gaps required in glass panels and doors should not exceed 4mm wide. h) Mirror Fixing Fix mirrors with proprietary concealed fixing system or with chrome plated dome headed screws. Do not distort when tightening fixings. Use spacer washers or buffers to compensate for irregularities in wall

    surfaces. Use sleeves and washers to prevent contact between mirror and fixings. i) Cleaning and Protection Do not use painted or stuck on indicators on solar control or colored glass. Whitewash may be used on

    ordinary glass but must be restricted to small central areas of panes. Seal compounds and putties as recommended by their manufacturers. Remove all smears and excess compound and leave clean inside and out and free from scratches. Replace all glass and fixing materials broken or damaged before Practical Completion and redecorate. 1.7 TILES a) All tiles are to be approved by the Consultant. Samples are to be submitted for approval prior to order. b) Laying Tiles Ensure that sub-surfaces are dry, true to plane and level, clean and free from contamination and loose

    areas. Start external wall tiling from the top and work downwards. Set out tiles so that our tiles are kept to a minimum and where they do occur is as large as possible. Lay out

    joints in straight unbroken lines. Horizontal joints in adjacent walls shall align. Carry movement joints through the full depth of tile and bedding. Partially fill with filler and finish flush with

    sealant to the manufacturers recommendations. Neatly cut and fit tiles around obstruction. Cut and grind edges of tiles shall be fully bedded. Clean and polish tile surfaces thoroughly upon completion. c) Bedding Wall Tiles in Mortar Soak tiles to suit the various types of tiles and allow draining. Wet backgrounds just sufficiently to prevent excessive absorption of water from the bedding mortar. Fill any deep keys or frogs and evenly butter the entire back of each tile with cement mortar (1:3) to give a

    finished bed thickness of 6mm. Place tiles and firmly tap into positions ensuring a solid bedding under the whole tile and proper adhesion over the whole of the background and the tile back.

    Grout joints not exceeding 3mm wide with neat white cement. Joint and point joints exceeding 3mm wide

    with white cement and sand (1:3).

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P18 - 18 -18

    d) Replacement of tiles will include hacking out existing tiles, preparation of levels to match and

    accommodate the new thickness of new finish inclusive of preparation of surfaces to receive new tiles. Areas where 2 types of finishing or colour must be separated by 3mm thick stainless steel of brass strip embedded into the joint.

    1.8 CEILING a) Installation Fix ceiling materials in accordance with manufacturers recommendation ensuring compliance with design

    and performance requirements. Set out accurately to give level soffits free from undulations and lipping, with all lines and joints straight and parallel to walls.

    Ensure that edge tiles/sheets are not less than half in width or length. Cut and fit tiles/sheets around recessed light fittings, air-conditioning diffusers, sprinkler heads and the like.

    Form openings for access panels together with additional trimming and framing, etc. Deflection between supports of any part of suspended ceilings shall not be more than 1/450 for spans up to

    1830mm and 1/600 for spans over 1830mm. b) Metal Support System Metal support systems shall be installed by the Contractor in conjunction with the ceiling lining manufacturer.

    All ferrous metals shall be rust-proofed. Hangers shall be substantial and sufficient to prevent excessive deflection in the ceiling. Suspension by means of wire will not be permitted. Additional hangers and support work shall be provided at recessed light fittings, diffusers and access panels, etc.

    c) Samples Sample of ceiling boards/hangers, etc. are required to be submitted for approval and mock up may be

    required, if necessary. d) Plasterboard Lining Plasterboard shall be 12.7mm thick tapered edge gypsum or glass fiber plasterboard to receive direct

    decoration complying with BS 1230. Boards shall be fixed with the ivory surface outward and tapered edges lightly butted. End joints shall be

    3mm wide and staggered. Supports shall be provided at all edges of boards. Fixing to timber shall be by means of 2mm diameter small flat head nails 40mm long. Nail heads small flat

    head nails 40mm long. Nail heads shall be driven home to form a shallow depression but not to break paper.

    Joints and finish boards in accordance with the manufacturers instructions to achieve a flush seamless surface ready for decoration.

    1.9 METAL WORKER a) Submit full shop drawings of all steel works. All steel works must be duly protected from the weather

    elements whilst in store or installed. b) Steel (hot rolled steel) to comply with BS 4 Part 1 and made from steel complying with BS 4360. Hot rolled

    steel bars to comply with BS 4449.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P19 - 19 -19

    c) Cold rolled sections to comply with BS 2994 from steel complying to BS 1449 Part 1. d) Steel plate to comply with BS 4360. And steel sheet and strips to BS 1449 Part 1. e) Steel tubes to comply with BS 1387 f) Steel mesh to comply to BS 1052 g) Galvanized Steel shall comply to BS 729, entirely coated in one operation with surface clean and uniform

    complying to BS 1367 with fittings complying to BS 1256. h) Stainless steel (type 304) to comply to BS 1449 Part 2 or BS 3014 as appropriate. i) All railings to be designed to horizontal/lateral loading in accordance to Table 4 of the 4th Schedule of BCA

    Regulation 1989, with height of railing at 1100 high and gaps of not more than 100mm. j) All welding must be full and through and in accordance to BS 5135, BS 5950, BS 449 and BS 4870 and

    4871. Weld splatter and oxides on exposed surfaces to be cleaned, treated and matched with finished surface.

    k) Do not leave exposed surfaces or surfaces damaged due to welding or jointing works to corrosion. Such

    areas to be appropriately protected. 1.10 LIGHTNING PROTECTION a) All metal structure and cladding must be fully bonded electrically to ensure continuity of building envelope

    and be grounded by earthing jumper cables, tapes and connections. b) Provide Lightning arresters as required. 1.11 BUILDING TOLERANCES a) Allow for all building tolerances, movements due to weather, heat noise and aircraft vibration from jet

    engines etc. b) Allow for building expansion joints to main building including structure( main and foundations) , floor slab,

    roof and structural frames. c) Allow for movement and settlement of ground.

    III PART 3 M&E SPECIFICATIONS 1.1 M&E SPECIALIST WORKS a) This M&E section is considered specialist works which is carried out under the appropriate trade and

    professional engineering license. In all cases, the system design, installation, testing and commissioning of the as built or installed M&E works must be endorsed, submitted (including shop drawings) and be approved by the relevant authorities including any licensing approvals.

    b) The itemized breakdown of the Tender Price as listed shall form only as an indication of the breakdown

    value for this contract works. c) Supply and installation of M&E equipment shall include supply, delivery, installation, testing, commissioning

    and other associated ancillary accessories.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P20 - 20 -20

    d) In carrying out the works the specialist licensed contractor and inclusive of the Engineer (CPE) must liaise directly with the Consultants to progress the works not only on site but with the authorities, CAG, CAAS etc.

    1.2 ELECTRICAL WORKS a) HV switchboards shall include circuit breakers, metering, BMS interfacing points, protection devices,

    terminal blocks, cable boxes, floor frames, batteries and other associated ancillary accessories as specified. b) Power transformers shall include all control panels, cable boxes, fittings and other associated ancillary

    accessories as specified. c) LV switchboards shall include circuit breakers, metering, BMS interfacing points, protection devices, terminal

    blocks, cable boxes, surge arrestors, heaters and other associated ancillary accessories as specified. d) Capacitor banks shall include harmonic filters, capacitors, wiring and other associated ancillary accessories

    as specified. e) Generator sets shall include AMF Panel, synchronized panel (if applicable), with associated wiring, exhaust

    ducting, silencer, day tank and pump and other associated ancillary accessories as specified. f) Busbar systems shall include tap off units, end feed units, end caps, joints, brackets, integrated with

    dedicated earth bar and other associated ancillary accessories as specified. g) Distribution boards shall include busbars, moulded case circuit breakers, miniature circuit breakers, residual

    current circuit breakers, time switches and other associated ancillary accessories as specified. h) Final circuits for lightings shall include wirings, cable support and containment systems, lighting switches

    and other associated ancillary accessories as specified. (50m run) i) Final circuits for small power and isolator shall include wirings, cable support and containment systems,

    switch socket outlets, isolators and other associated ancillary accessories as specified. (50m run) j) Floor trunking installation shall include junction boxes, vertical access boxes, service outlet boxes, fittings

    and other associated ancillary accessories as specified. k) Light fittings and fixtures shall include lamps, control gears, starters, brackets and other associated ancillary

    accessories as specified. l) External street light fittings and fixtures shall include lamps, control gears, starters, brackets, lamp posts and

    other associated ancillary accessories as specified. m) Exit signs and emergency light fittings and fixtures shall include lamps, control gears, starters, brackets,

    battery packs and other associated ancillary accessories as specified. n) Security systems shall include uninterruptible power supply, servers, workstations, equipment racks,

    application software, firewall software, cablings and other associated ancillary accessories as specified. o) Power, data and control cabling systems shall include cable support and containment systems and other

    associated ancillary accessories as specified. p) TV / FM outlets shall include coaxial cable, TV / FM outlets, cable support and containment system and

    other associated ancillary accessories as specified. q) CATV/MATV/TVRO systems shall include head-end equipment, cables, splitters, tap-off units, coaxial

    cables for TV/FM outlets and other associated ancillary accessories as specified.

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P21 - 21 -21

    r) Head-end equipment for CATV/MATV/TVRO system shall include amplifiers, booster units, antennas, cabinets, power supply units and other associated ancillary accessories as specified.

    s) Vehicle barrier systems shall include vehicle barrier units, control panels, intercoms, transponder readers,

    cameras, power supply, cables, card transponders or transponder discs and other associated ancillary accessories as specified.

    t) Vehicle barrier units shall include safety loop detectors and other associated ancillary accessories as

    specified. u) EPS entry and exit stations shall include microprocessor-based controllers, UPS, LED display signs, cash

    card readers, intercoms, antennas and other associated ancillary accessories as specified v) PC-based management control stations shall include CPUs, modems, printers, monitors, UPS, application

    software and other associated ancillary accessories as specified w) EVCS/PA system equipment shall include equipment paging consoles, racks, amplifiers, tuners, CD players,

    fault monitoring panels, over-riding switch, UPS, hardware, software and other associated ancillary accessories as specified

    x) Speakers shall include housings, mounting brackets and other associated ancillary accessories as specified. y) Lightning protection system shall include roof conductors, air terminals, equipotential bonding to metallic

    parts, down conductors, earth electrodes, earth pits and other associated ancillary accessories as specified z) Main earthling system shall include earth continuity conductors, copper tapes, earth bars, equipotential

    bonding, earth rods, earth pits and other associated ancillary accessories as specified aa) Services and maintenance during defects liability or maintenance period shall include the supply of all labor,

    materials, tools, transport and everything necessary to carry out scheduled servicing and maintenance as specified.

    1.3 FIRE SERVICES a) All works, systems, materials, equipment and installation are to comply to all relevant Authorities especially

    the FSSB and Airport Fire Services with approval including all submissions by specialist or professional engineer responsible for the system. The Contractors specialist/licensed Fire Services provider or engineer is deemed to understand the requirements of the FSSB Code of practice as required for the Project.

    1.4 PLUMBING SERVICES a) All works, systems, materials, equipment and installation are to comply to all relevant Authorities especially

    the NEA with approval including all submissions by specialist or professional engineer responsible for the system. The Contractors specialist/licensed Plumber/provider or engineer is deemed to understand the requirements of the NEA which includes CBPU, PUB (Sewerage), PUB(Drainage) Code of practice as required for the Project.

    1.5 MECHANICAL SERVICES a) All works, systems, materials, equipment and installation are to comply to all relevant Authorities with

    approval including all submissions by specialist or professional engineer responsible for the system. The Contractors specialist/licensed mechanical sub-contractor or engineer is deemed to understand the requirements of the BCA/Authority which includes CBPU, PUB (Sewerage), PUB(Drainage) if required, their Code of practice for the Project.

    END

  • CT1401B001

    ARCHITECTURAL & SERVICES SPECIFICATIONS APPENDIX C : ANNEX A

    P22 - 22 -22

  • MTECH CONSULTANTS

    S1/1

    SECTION 1 - CONCRETE WORKS

    1 REINFORCED CONCRETE WORKS

    1.1 General

    The reinforced concrete work is to comply with the requirements of the British Code

    of Practice BS 8110 "The Structural Use of Concrete" and subsequent revisions

    thereof.

    So far as is practicable or unless otherwise specified, materials shall comply with the

    appropriate latest Singapore Standards or British Standards where the Singapore

    Standards do not exist. Where the requirements of the relevant Singapore or British

    Standards are in conflict with this Specification, then this Specification shall take

    precedence.

    Materials used in the Works shall be of the qualities and kinds specified

    herein and equal to approved samples. Delivery shall be made sufficiently in

    advance to enable samples to be taken and tested if required. No materials shall be

    used until and unless approved and materials not approved shall be immediately

    removed from the vicinity of the Works at the Contractor's own expense.

    Materials shall be transported, handled and stored on the site or elsewhere in such a

    manner as to prevent damage, deterioration or contamination all to the satisfaction of

    the Engineer. The Engineer reserves the right to inspect any materials to be used on

    the Works at any time and at any place of storage.

    If required, the Contractor shall supply to the Engineer the appropriate certificate of

    compliance with the Standards. Notwithstanding the above, tests shall be carried out

    as and when directed by the Engineer in accordance with the relevant Singapore

    Standards and/or British Standards.

    1.2 Cement

    The cement used shall be of approved manufacture. Portland cement shall comply

    with the requirements of BS 12 or SS 26. Portland-Blast-Furnance Cement shall

    comply with the requirements of BS 146. Sulphate-resisting cement shall comply

    with BS 4027. Manufacturer's certificates of test will generally be accepted as proof

    of soundness, but the Engineer may require additional tests to be carried out on any

    cement which appears to have deteriorated through age, damage to containers,

    improper storage or for any other reason. The Engineer may, without tests being

    made, order that any bag of cement, a portion of the contents of which has hardened,

    or which appears to be defective in any other way, be removed from the site

    forthwith. No cement shall be used in the works until it has been passed as

    satisfactory by the Engineer.

  • MTECH CONSULTANTS

    S1/2

    The Contractor may if the Engineer approves, elect to use types of cement other than

    ordinary Portland, but no extra will be paid on account of using a cement priced

    higher than the price for the type specified, unless work using such cement is

    ordered in writing by the Engineer.

    The cement shall be transported to the site in covered vehicles adequately protected

    against water. Bagged cement shall be stored in a weather-proof cement store and

    shall be taken for use in the works in the order of its delivery into the store. Bulk

    cement is to be stored in properly constructed silos. Arrangements for transport,

    general delivery, planning, storage and certification shall be fully provided to the

    Engineer before orders are placed.

    1.3 Aggregates Generally

    The fine and coarse aggregates shall be naturally occurring sands, gravel or stone,

    crushed or uncrushed, and shall comply with the requirements of Singapore

    Standards (SS) 31:1971 or BS 882 "Crushed Aggregate from Natural Sources". They

    shall be obtained from a source approved by the Engineer and shall be hard, strong,

    durable, clean and free from adherent coatings and shall not contain any harmful

    material in sufficient quantity to adversely affect the strength, durability

    impermeability of the concrete or to attack the steel reinforcement. They shall not

    contain water-soluble sulphur trioxide (SO3) in excess of 0.1%.

    1.4 Fine Aggregate

    The fine aggregate shall not contain silt or other fine material exceeding 3% by

    weight when tested according to the standard method given in BS 812. As a guide,

    the field setting test may be used to determine the silt content and should normally

    not show more than 10% silt by volume.

    The fine aggregate shall not contain organic material in sufficient quantity to render a

    mean pH value of 12.2 or lower at a temperature of 110C, when tested according to

    the method in BS 812, Clause 32 on "Organic Impurities". The Contractor shall

    screen all fine aggregates as and when required by the Engineer.

    1.5 Coarse Aggregate

    The coarse aggregate shall be granite or other hard stone from a source approved by

    the Engineer. The aggregate shall not contain clay exceeding 1% by weight.

    Representative dry sample shall not show an increase in weight exceeding 8% after

    immersion in water when tested as laid down in BS 812 Clauses 19 to 21. It shall be

    well shaped and its flakiness index shall not exceed 35. The nominal size of coarse

    aggregate shall be as stipulated below.

  • MTECH CONSULTANTS

    S1/3

    1.6 Aggregate Grading

    The grading of aggregate shall comply with BS 882 Clause 5 and shall be within the

    limits as shown in Tables 1.1 and 1.2. The grading between the limits specified

    above shall be to the satisfaction of the Engineer and when tested as provided for in

    this Section, shall approximate closely to the grading of the samples approved by

    him. If it should be found necessary, the fine aggregate shall be washed and screened

    to comply with the foregoing standards and the requirements of the Engineer.

    1.7 Sampling and Testing of Aggregates

    Tests shall be carried out on samples of the latter taken at intervals as laid down in

    Clause 1.4 below or as required by the Engineer. The method of sampling and the

    amount of aggregate to be provided for the tests shall be in accordance with BS 812,

    Section One, "Sampling of aggregates". The test shall be those laid down in BS 812,

    Sections Two to Six, inclusive. The tests will be carried out by the contractor in the

    presence of the Engineer, or his representative. Should a sample fail to comply with

    any of the tests, the Engineer may, at his discretion, either the batch from which the

    sample was taken, order it be washed and/or screened, or permit it to be used with

    variations in the proportions of the concrete mixes specified. Any batch of aggregate

    rejected by the Engineer shall be removed from the Works or site forthwith.

  • MTECH CONSULTANTS

    S1/4

    Table 1.1 Coarse Aggregate

    Percentage by Weight Passing BS Sieves

    BS 410:1976

    Test sieve

    Nominal size of graded

    aggregate

    Nominal size of single-sized

    aggregate

    1.5

    in. to

    3/16

    in.

    (38

    mm

    to

    5

    mm)

    3/4

    in. to

    3/16

    in.

    (19

    mm

    to

    5

    mm)

    1/2

    in. to

    3/16

    in.

    (13

    mm

    to

    5

    mm)

    2.5 in.

    (64

    mm)

    1.5 in.

    (38

    mm)

    3/4 in.

    (19

    mm)

    1/2 in.

    (13

    mm)

    3/8 in.

    (10 mm)

    In.

    mm

    3

    76.2

    0

    100 - - 100 - - - -

    2 1/2

    63.5

    0

    - - - 85 -

    100

    100 - - -

    1 1/2 38.1

    0

    95 -

    100

    100 - 0 - 30 85 -

    100

    100 - -

    3/4 19.0

    5

    30 -

    70

    95 -

    100

    100 0 - 5 0 - 20 85 -

    100

    100 -

    1/2 12.7

    0

    - - 90 -

    100

    - - - 85 -

    100

    100

    3/8 9.52 10 -

    35

    25 -

    55

    40 -

    85

    - 0 - 5 0 - 20 0 - 45 85 - 100

    3/16

    4.76 0 - 5 0 - 10 0 - 10 - - 0 - 5 0 - 10 0 - 20

    No.

    mm

    7

    2.40 - - - - - - - 0 - 5

    Samples of the fine and coarse aggregates approved by the Engineer shall be kept on

    site, and shall give a fair indication of the general quality of the aggregates for

    comparison with the aggregates delivered during the course of work.

    1.8 Storage of Aggregates

    All aggregates for concrete shall be stored in bays with drainage slopes or in bins

    in such a manner as to prevent segregation of sizes and to avoid the inclusion of dirt

    and other foreign materials in the concrete. The storage bays shall be protected from

    rainfall in order to prevent excessive changes in moisture content taking place. Each

    size of aggregate shall be stored separately unless otherwise approved.

    The bottom 300 mm of each stockpile shall not be used in concrete but shall be left

    in position throughout the contract to act as a drainage layer.

  • MTECH CONSULTANTS

    S1/5

    Table 1.2 Fine Aggregate

    BS 410:1976

    test sieve

    Percentage by Weight Passing BS Sieve

    Grading

    Zone 1

    Grading

    Zone 2

    Grading

    Zone 3

    Grading

    Zone 4

    in

    mm

    3/8

    9.52 100 100 100 100

    3/10

    4.76 90 - 100 90 - 100 90 - 100 90 - 100

    No.

    mm

    7

    2.40 60 - 95 75 - 100 85 - 100 95 - 100

    14

    1.20 30 - 70 55 - 90 75 - 100 90 - 100

    No.

    microns

    25 600

    15 - 34 35 - 59 60 - 79 80 - 100

    52

    300 5 - 20 8 - 30 12 - 40 15 - 50

    100

    150 0 - 10 0 - 10 0 - 10 0 - 15

    1.9 Water

    The water shall be clean and free from harmful matter and shall be from a source

    approved by the Engineer, such as the city's potable water supply system. The

    Contractor shall make adequate arrangements to deliver and store sufficient water at

    the works site for use in mixing and curing the concrete. Water shall comply with

    the requirements of the latest edition of BS 3148.

  • MTECH CONSULTANTS

    S1/6

    1.10 Reinforcement

    (a) Quality

    Hot-rolled Mild Steel and High Tensile Steel reinforcement must be obtained from

    manufacturers who have been approved in writing by the Engineer and shall comply

    with Singapore Standard (SS) 2 or BS 4449 with regard to strength and elasticity.

    Cold worked steel bars shall comply to BS 4461. Steel fabric reinforcement shall

    comply with SS32 or BS 4483. All reinforcement shall be hammered free from

    scale, scraped and wire-brushed free from all loose rust and after such treatment shall

    be within the margins over and under which are allowed by the abovementioned

    British Standard. It shall not be coated with any grease oil, paint or preservative.

    High tensile steel fabric when used shall comply with BS 4483. Strength of steel

    for concrete reinforcement shall be as given in Table 1.3.

    (b) Where the letter T is used in the structural detailing, it shall mean that such

    reinforcement shall be high tensile bars having a minimum characteristic tensile

    strength of 460 N/mm2 at a proof strain of 0.002 as tested to BS 4449.

    (c) The letter R, where used, shall indicate that such reinforcement shall be

    mild steel bars with a minimum characteristic strength of 250 N/mm2.at a proof

    strain of 0.002 as tested to BS 4449.

    (d) Sampling and control

    The Contractor shall furnish, for reinforcement supplied by him, manufacturer's

    certificates and these shall be submitted for acceptance by the Engineer, before any

    material is brought onto the site. In addition, the Contractor shall, on request,

    furnish the Engineer with a test sheet for any batch of bars, giving the results of

    each of the mechanical tests required under British Standards.

    In the event of any reinforcement being found to be not in accordance with the

    British Standards in the course of being worked, it may be rejected by the Engineer

    notwithstanding any previous acceptance on the strength of the test certificates and

    the Engineer may call for additional tests to be made at the Contractor's expense on

    samples taken from the batch of bars from which the faulty reinforcement came. If

    the samples do not satisfy the Standards requirements, then the Engineer may reject

    the whole batch and require its removal from the works site.

    The frequency of sampling and testing shall be according to the following Table 1.4.

  • MTECH CONSULTANTS

    S1/7

    Six test specimens are to be prepared from each sample. The length required for

    each specimen shall be 300 mm. The deviation in weights and effective cross-

    sectional areas shall not exceed those given in BS 4449 and routine sampling shall

    be carried out for each nominal size used at the rate of one (1) sample per 1,000

    bars or part thereof.

    Table 1.3 Strength of Reinforcement

    Designation

    Nominal Sizes Specified

    Characteristic

    Strength, fy

    at 0.002 proof strain

    mm

    N/mm2

    Hot rolled mild steel

    (SS 2, BS 4449 : 1978)

    All sizes

    250

    Hot rolled high tensile

    (SS 2, BS 4449 : 1978)

    460 Grade

    All sizes

    460

    Cold worked high tensile

    (BS 4461 : 1978)

    460 Grade

    All sizes

    460

    Hard drawn steel wire

    (BS 4482 : 1969)

    Up to and including

    12

    485

    Table 1.4 Frequency of sampling and testing of reinforcement

    Diameter of bar (mm) One sample for tensile and bend tests from each

    Under 10

    5,000 bars (25 tonnes or part)

    10 to 12

    3,000 bars (35 tonnes or part)

    16 to 20

    1,500 bars (45 tonnes or part)

    Over 22

    1,000 bars (45 tonnes or part)

    (e) Cleaning

    The reinforcement shall be cleaned free from loose mill scale and loose rust before

    being placed in the forms and shall be free from these and from oil, grease or other

    harmful matter at the time when the concrete is placed.

  • MTECH CONSULTANTS

    S1/8

    (f) Bending

    The reinforcement shall be bent cold in an approved bar bending machine. The

    bending dimensions and tolerances and the dimensions of end anchorages, hooks,

    binders, stirrups, links and the likes shall be in accordance with BS 4466. The

    minimum diameter of the former for bending shall be 4 times the bar diameter for

    mild steel and 6 times the bar diameter high tensile steel.

    (g) Placing

    The reinforcement shall be placed in the forms and held firm against displacement,

    by approved types of small precast concrete fixing blocks and wire ties, in the exact

    position shown in the approved Construction Drawings, or, if not shown, to the

    Engineer's approval. Fixing blocks may be left embedded in the concrete in cases

    where the Engineer approves. Bars intended to be in contact when passing each

    other shall be securely held together at intersection points with tying wire. Binders

    and stirrups shall tightly embrace the longitudinal reinforcement to which they shall

    be securely wired together or spot welded.

    The wire ties used shall be No. 20 S.W.G. soft annealed iron wire ; the ends shall be

    turned in from the face of the framework and shall not be left projecting beyond the

    reinforcing bars. The reinforcement shall be inspected and passed by the Engineer or

    his representative before concrete is placed in the forms. The required amount of

    cover over the reinforcement shall be obtained when the reinforcement is placed and

    shall be held to this during concreting.

    The following tolerances in Table1.5 are generally applicable for reinforcement steel

    in place.

    Reinforcement wrongly placed shall be re-positioned or replaced by an equivalent

    amount of bars in the correct position to the satisfaction of the Engineer.

  • MTECH CONSULTANTS

    S1/9

    Table 1.5 Tolerances for reinforcement steel in place

    Item

    Allowable Tolerance

    Size of bar

    Nil

    Cover

    +5mm, -2mm

    Height, effective

    +5 mm

    Position of hook

    +50 mm

    Spacing

    +15 mm

    Number of bars

    Nil

    (h) Laps

    Laps shall be as shown in the Drawings. Where not indicated, laps shall be as listed

    in Table 1.6.

    Fabric reinforcement sheets are to overlap by 300 mm.

    Table 1.6 Lap length of reinforcement bars

    Lap length in number of bar diameter

    Grade of

    Concrete

    Mild steel reinforcement

    High tensile steel reinforcement

    Bars with

    U-Hooks

    Bars without

    U-Hooks

    Bars with

    U-Hooks

    Bars without

    U-Hooks

    30 or better

    35

    50

    37

    52

    25

    39

    55

    40

    57

  • MTECH CONSULTANTS

    S1/10

    (j) Welding

    Welding of mild reinforcement by electric arc may be permitted by the Engineer

    under suitable conditions and with suitable safeguards. Welding shall be carried out

    in accordance with BS 5135 "Metal Arc Welding of Carbon and Carbon Manganese

    Steels". Butt welds shall be of double V type and two butt weld bend tests shall be

    carried out on a specimen prepared to represent each form of butt welded joint used

    in the welding. The method of making butt weld test shall be that laid down in BS

    709. The specimen shall pass the tests to the satisfaction of the Engineer before

    approval is accorded to use the joint which the specimen represents. Tack welds

    between reinforcing bars, used merely to fix them in position, shall not be subject

    to tests.

    1.11 Storage of Reinforcements

    The reinforcement shall be stacked tidily in a manner that permits inspection.

    1.12 Contractor's Concrete Batching Plant

    The Contractor's concrete batching and mixing plant shall be subject to approval by

    the Engineer and he should therefore submit his proposal to the Engineer prior to

    erection and use.

    1.13 Ready mixed Concrete

    Ready mixed concrete shall be used for this project. The Contractor shall furnish the

    name of his ready mixed concrete Supplier to the Engineer for approval. He shall

    make such arrangements as may be required for the Engineer to inspect his Supplier's

    works and provide all facilities for samples of cement, fine and coarse aggregates

    and admixtures to be selected for testing by an approved PSB accredited laboratory.

    Notwithstanding any such inspection having been made and/or approval given by the

    Engineer, the Contractor shall take full responsibility for ensuring that all ready

    mixed concrete supplied shall conform to SS 119 : 1975 or BS 5328 : 1981 and this

    entire Specification. Concrete that does not comply with this entire Specification

    shall be rejected and removed from Site by the Contractor at his own expense.

    The Contractor shall furnish to and obtain the approval of the Engineer at least one

    day in advance of the date set for each casting of concrete, the number of transit

    trucks/truck mixer/truck agitators proposed to be used to supply the concrete and the

    frequency at which the loads of concrete are to be delivered to the Site.

  • MTECH CONSULTANTS

    S1/11

    For each truck load of concrete delivered, the following information shall appear on

    the delivery docket :

    (1) Name of ready mixed concrete batch plant

    (2) Serial number of docket

    (3) Date and the license number of the truck

    (4) Name of the purchaser

    (5) Name and location of job

    (6) Specified characteristic concrete strength and the amount of

    cement used (kg) or the mix proportions

    (7) Quantity of concrete

    (8) Time of loading or of first mixing of cement and aggregates,

    whichever is earlier

    (9) Agreed slump

    (10) Maximum size of coarse aggregates specified

    (11) Trade name of admixture, if any

    (12) The signature of the Supervisor who shall also enter the time of

    arrival of the truck and the time of completion of discharge

    (13) Position where concrete is placed

    (14) Number of cubes taken if any, and cube reference codes

    (15) Temperature of mix when received and during the pour

    (16) Any other requirements as may be instructed

    One copy of the docket shall be given to the Engineer on delivery.

    The Engineer reserves the right to instruct the Contractor to change the Supplier in

    view of unsatisfactory performance or to rescind his approval for further use of ready

    mixed concrete during the progress of the Works if any of the requirements of this

    Specification has, in his opinion, not been satisfactorily complied with.

    No water in excess of the quantity required in the approved mix shall be allowed to

    be added to the concrete to increase its workability affected by elapsed time and/or

    temperature.

    While it is not being discharged, the concrete in a transit truck/truck mixer/truck

    agitator shall be kept continuously agitated.

    The concrete shall be placed in its final position and left undisturbed within two

    hours from the time when the cement was added to the mix. Deviations from this

    time interval may be permitted by the Engineer subject to trial mixes carried out.

  • MTECH CONSULTANTS

    S1/12

    1.14 Grades of Concrete

    The grades of concrete to be used in the Works shall be as shown in the Drawings.

    For each grade of concrete the mix shall be designed so that, when tested in

    accordance with this Specification the minimum works cube strength and the

    minimum and maximum cement contents shall be as set out in Table 1.7.

    Attention is drawn to the fact that the specified strengths given in Table 1.7 are

    minimum strengths. Whilst it is appreciated that the Contractor may use statistical

    methods, values of sets of 28 day works cube test shall not be considered

    satisfactory if the requirements of Clause 1.19 in this Specification are not met.

    Preliminary trial mixes of each of the classes of concrete to be used in the Works

    shall be made by the Contractor to ensure that, the mix as designed will comply with

    the strength and other requirements of this Specification.

    Trial mixes shall be carried out at such a time so that final mixes to be used shall be

    agreed well in advance of requirements.

    For each grade of concrete, a set of 8 cubes shall be made from each of 3

    consecutive batches. Four cubes from each set of 8 cubes shall be tested at 7 days

    and the remainder at 28 days. Cubes shall be made, cured, stored and tested all in

    accordance with SS 78: 1972. Preliminary cube strength tests results shall exceed the

    minimum strength requirements of Table 1.7 by not less than 33%.

    In order to satisfy the Engineer that the workability of the proposed mixes is such

    that the concrete can be readily worked into corners, recesses and around all

    reinforcement without segregation or "bleeding", the Contractor shall carry out a

    series of workability tests on the preliminary trial mixes in accordance with SS 78 :

    1982.

    No concrete shall be placed until the Supplier has received the Engineer's approval

    for the mix proportions.

    The Contractor shall not vary the approved mixed proportions, size or grading of

    aggregates nor alter the sources of supply of materials without the prior approval of

    the Engineer.

    Alterations to mixes already approved by the Engineer shall be subjected to further

    trial mixing as specified.

    The Engineer may order alterations to mix proportions should works cube test results

    indicate that such changes are necessary in order to comply with specified strength

    and workability requirements. No additional payment shall be made in respect of

    such variations to mixes whether ordered by the Engineer or requested by the

    Contractor himself.

  • MTECH CONSULTANTS

    S1/13

    1.15 Cement Content

    For ordinary reinforced concrete, the cement content for water retaining structures

    and structures in contact with water/ground, shall not be less than 400 kg/m3 unless

    written approval is obtained.

    1.16 Admixtures

    All admixtures shall comply with BS 5075 Parts 1 and 3.

    (a) No admixtures will be permitted without written permission and in no

    circumstances will chloride admixtures be allowed. In the event of

    permission being granted in principle the tests described in the Specification

    shall be carried out with the intended proportion of admixture incorporated

    and comparison shall be made with concrete manufactured without the

    admixtures to prove that the density has not been reduced below 2320 kg/m3.

    (b) When admixtures are used on the Works, very strict control is to be maintained to

    ensure that the correct quantity of admixture is used at all times. Admixtures

    containing chlorides shall not be used.

  • MTECH CONSULTANTS

    S1/14

    Table 1.7 Grades of Concrete

    Grade of

    concrete

    50

    45

    40

    35

    30

    25

    20

    15

    10

    Minimum cube

    crushing

    strength, in

    N/mm2

    7

    day

    40

    35

    30

    26

    23

    19

    15

    11

    -

    Minimum cube

    crushing

    strength, in

    N/mm2

    28

    day

    50

    45

    40

    35

    30

    25

    20

    15

    -

    Minimum

    recommended

    cement content

    in kg/m3 of

    fully

    compacted

    concrete

    430

    415

    400

    390

    375

    330

    300

    290

    250

    Maximum

    cement content

    in kg/m3 of

    fully

    compacted

    concrete

    550

    550

    550

    550

    550

    550

    550

    550

    550

    Maximum

    water/cement

    ratio

    0.45

    0.45

    0.50

    0.50

    0.50

    0.50

    0.55

    0.55

    0.65

  • MTECH CONSULTANTS

    S1/15

    1.7 Requirements for Mix Design

    (a) The Contractor shall submit details of his mix design to the Engineer for his

    provisional approval. Details submitted shall include:

    (i) the type and source of cement

    (ii) the type and source of aggregate

    (iii) the grading details, in tabular and graphical form, of the fine and

    coarse aggregates

    (iv) the grading details, in tabular and graphical form, of the combined

    aggregates, together with details of the proportions in which the fine

    and coarse aggregates are to be combined

    (v) the aggregate-cement ratio by weight

    (vi) the water-cement ratio by weight

    (vii) the workability in terms of both slump and compacting factor having

    due regard to the final location and dimensions of the concrete

    (viii) the target mean strength and the current margin.

    (b) The concrete mix shall be designed to have at least the required minimum cement

    content and to have a mean strength greater than the required characteristic

    strength by at least the current margin.

    (c) The current margin for each particular type of concrete mix shall be taken as

    having the smaller of the values given by (i) or (ii).

    (i) 1.64 times the standard deviation of cube tests on at least 100

    separate batches of concrete of nominally similar proportions of

    similar materials and produced over a period exceeding 5 days but

    not exceeding 6 months by the same plant under similar supervision,

    but not less than 1

    /3 of the characteristic strength for concrete

    grades 10 or 15, or 7.5 N/mm2 for concrete of grade 20 and above.

    (ii) 1.64 times the standard deviation of cube tests on at least 40 separate

    batches of concrete of nominally similar proportions of similar

    materials and produced over a period exceeding 5 days but not

    exceeding 6 months by the same plant under similar supervision, but

    not less than 1

    /3 of the characteristic strength for concrete grades 10

    or 15, or 7.5 N/mm2 for concrete of grade 20 and above.

  • MTECH CONSULTANTS

    S1/16

    (d) When there are insufficient data to satisfy (i) or (ii) above, the margin for the

    initial mix design shall be taken as 2/3 of the characteristic strength for

    concrete of grades 10 or 15, or 15 N/mm2 for current margin only until

    sufficient data are available to satisfy (i) or (ii) above. However, when the

    required characteristic strength approaches the maximum possible strength of

    concrete made with a particular aggregate, a smaller margin but not less than

    7.5 N/mm2 shall be permitted for the initial mix design subject to the prior

    approval of the Engineer.

    (e) Evidence shall be submitted to the Engineer for each grade of concrete

    showing that at the intended workability, the proposed mix proportions and

    manufacturing method will produce concrete of the required quality.

    (f) Three separate batches of concrete shall be made for trial mixes using

    materials from the proposed supply and under full scale production

    conditions. Sampling and testing shall be in accordance with BS 1881.

    (g) The workability of each of the trial batches shall be determined and four cubes

    made from each batch for test at 28 days. A further four cubes from each

    batch shall be made for each test at 3 days and 7 days. The trial mix

    proportions are adequate if the average strength of the 12 cubes tested at 28

    days exceeds the specified characteristic strength by the current margin

    minus 3.5 N/mm2 or if twelve tests at an earlier age indicate that it is likely

    to be exceeded by this amount.

    (h) Trial mixes will be required to demonstrate that the maximum free water/cement

    ratio is not exceeded. Two batches shall be made in laboratory with cement

    and surface dry aggregates known, from past records of the suppliers of the

    material, to be typical. The proposed mix proportions shall not be accepted

    unless both batches have the correct cement content and a free/water cement

    ratio below the maximum specified value at the proposed degree of

    workability. For this purpose, existing laboratory test reports may be

    accepted instead of trial mixes only if the Engineer is satisfied that the

    materials to be used in the structural concrete are likely to be similar to those

    used in the tests.

    (j) During production, the Engineer may require trial mixes to be made before a

    substantial change is made in the materials or in the proportions of the

    materials to be used.

  • MTECH CONSULTANTS

    S1/17

    (k) During production, adjustments of mix proportions can be made, in order to

    maximize the variability of strength to approach more closely the target mean

    strength, provided the express approval of the Engineer is obtained. Such

    adjustments are regarded as part of the proper control of production but the

    specified limits of minimum cement content and maximum water/cement

    ratio shall be maintained. Changes in cement content shall have to be

    declared. Such adjustments to mix proportions shall not be taken to imply

    any changes to the current margin.

    (l) A change in the current margin used for judging compliance with the

    specified characteristic strength will become appropriate when the results of

    a sufficiently large number of tests show that the previously established

    margin is significantly too large or too small. Recalculation of the margin

    should be carried out in accordance with sub-clause (c) but, although a

    recalculated margin is almost certain to differ numerically from the previous

    value, the adoption of the recalculated value would not generally be justified

    if the two values differ by less than 18 per cent when based on tests on 40

    separate batches; less than 11 per cent when based on tests on 100 separate

    batches or less than 5 per cent when based on tests on 500 separate batches.

    (m) On adoption of a recalculated margin, it becomes the current margin for the

    judgement of compliance with the specified characteristic strength of

    concrete produced subsequently to the change.

    1.18 Quality Control Sampling and Testing

    (a) Initial sampling and testing of cement, aggregates, water, plant and concrete trial

    mixes shall be conducted as stated above.

    (b) Routine quality control tests shall subsequently be conducted throughout the

    whole period of this Contract by the Contractor for all concrete works. A

    record of these tests shall be kept on the works, identifying particular

    portions of concrete in the works with the respective samples and tests made.

    Copies of all test records shall be submitted to the Engineer promptly on

    completion of each respective test.

    The tests shall be carried out for the following items in Table 1.8.

  • MTECH CONSULTANTS

    S1/18

    Table 1.8 Routine quality control tests

    Item

    Tests

    Remarks

    Aggregates Field silt test for sand One test per day

    Surface moisture of coarse

    aggregate

    As directed by the Engineer after

    rain. Adjustment of mixing water

    is necessary for any change.

    Surface moisture of fine aggregate

    Twice a day.

    For any change adjust the quality of

    water

    Concrete Slump tests or Compacting Factor

    test on fresh concrete

    For first batch of each placement,

    and twice more per day during

    mixing.

    Value should be within +25 mm of

    required slump.

    Cubes for compressive strength

    See sub-clause (c) below

    Minimum cement content See sub-clause (c) below

    Specimens for flexural strength,

    and core tests.

    To be sampled if and when

    directed. Make 3 specimens from

    each sample.

    Plant

    Inspection of gauges Daily check for accuracy required

    before use.

    Limit of tolerance to be +2%.

  • MTECH CONSULTANTS

    S1/19

    (c) Compressive Strength Tests on Concrete

    (i) Concrete strength will be based on tests on cubes at 28 days age. The

    practical advantages of testing at 3 or 7 days or by use of accelerated

    curing methods are recognised and where carried out, may be

    allowed to assist the Engineer and the Contractor in the interim for

    provisional acceptance of the concrete strength and quality on a pro-

    rata basis. Final acceptance, however, will be based on the 28-day

    cube test results or the test results for cube strengths in excess of the

    targeted 28 day strength, if achieved earlier.

    (ii) The characteristic strength is defined as the 28-day strength below

    which 5% of the tests fail.

    (iii) The concrete quality control system adopted is a statistical one

    depending on the standard deviation, s, of the 28-day cube test

    results where

    s = (x - m)2

    n - 1

    and x = an individual result

    n = number of results

    m = mean of n results

    (iv) The concrete shall be sampled according to one of the rates specified

    below in Table 1.9 below as selected by the Engineer who will be

    expected to choose a rate applicable to the degree of control of

    workmanship and material quality exercised by the Contractor as

    well as the nature of the work. Ordinarily, Rate 1 is applicable to

    highly stressed and to critical members such as columns, transfer

    beams and cantilevered beams, Rate 2 to ordinary work and Rate 3

    is for mass concrete work.

    Table 1.9 Rate of Sampling

    Rate 1

    Rate 2

    Rate 3

    Volume of Concrete per

    Sample

    10 m3

    or 5 batches

    50 m3

    or 10 batches

    100 m3

    or 20 batches

    whichever is the lesser volume

  • MTECH CONSULTANTS

    S1/20

    (v) Two cubes shall be made from each randomly selected sample under

    Rate 1. A single cube shall be made from each randomly selected

    sample under Rates 2 and 3. All the concrete in any one sample shall

    be taken from a single batch. Sampling shall be taken at the point of

    discharge of the mixer, or in the case of ready-mixed concrete, at

    the point of discharge from the delivery truck.

    (vi) The concrete complies with the specification if :

    A. The average strength of any group of 4 consecutive test cubes

    exceeds the characteristic strength by half the current margin

    (See Tables 1.10 and 1.11 below).

    B. Each individual test result is greater than 85% of the

    specified characteristic strength,

    or

    C. For small projects, the acceptance criteria is based on a

    group of four (4) concrete cubes.

    C.1 Each of the four (4) cubes in a group has a strength not less

    than the specified characteristic strength

    or

    C.2 Not more than one cube has a test strength less than the

    specified characteristic strength but not less than 85% of the

    specified characteristic strength, and the average strength of

    the group is not less than the specified characteristic strength

    plus the standard deviation of the group.

  • MTECH CONSULTANTS

    S1/21

    Table 1.10

    Initial current margin and required minimum cube strength less than 40 batches and 6 days

    production.

    Grade

    Characteristic Strength

    N/mm2

    Half the Current

    Margin

    N/mm2

    Required Minimum

    Value of Mean of 4

    cubes

    N/mm2

    7

    7

    2.3

    9.3

    10 10 3.3 13.3

    15 15 5.0 20.0

    20 20 7.5 27.5

    25 25 7.5 32.5

    30 30 7.5 37.5

    35 35 7.5 42.5

    40 40 7.5 47.5

  • MTECH CONSULTANTS

    S1/22

    Table 1.11

    Current margin and required minimum cube strength for more than 40 batches (Produced

    between 5 days to 6 months)

    Grade

    Characteristic

    strength, C

    N/mm2

    Half current margin

    N/mm2

    * Required average

    value of 4 cubes

    = C + C'

    N/mm2

    C'

    Minimum value

    of C'

    7

    7

    0.82S

    1.17

    7 + 0.82S,

    or 8.17

    10

    10

    0.82S

    1.67

    10 + 0.82S,

    or 11.67

    15

    15

    0.82S

    2.50

    15 + 0.82S,

    or 17.50

    20

    20

    0.82S

    3.75

    20 + 0.82S,

    or 23.75

    25

    25

    0.82S

    3.75

    25 + 0.82S,

    or 28.75

    30

    30

    0.82S

    3.75

    30 + 0.82S,

    or 33.75

    35

    35

    0.82S

    3.75

    35 + 0.82S,

    or 38.75

    40

    40

    0.82S

    3.75

    40 + 0.82S,

    or 43.75

    * The greater of the two alternative figures given for each grade shall be the minimum required

    strength value.

    (vii) The minimum value of C' given in Table 1.11 may be further reduced to half

    by the Engineer if warranted by the results of more than 100 consecutive

    batches of concrete.

  • MTECH CONSULTANTS

    S1/23

    (viii) The required minimum values given by Table 1.10 shall be considered an

    interim result pending the subsequent production up to 40 batches and 6 days

    production time.

    (ix) If more than one cube in a group fails to meet the second requirement or if

    the average strength of any group of four consecutive test cubes fails to meet

    the first requirement, then all the concrete in all the batches represented by

    all such cubes shall be deemed not to comply with the strength requirements.

    For the purpose of this sub-clause the batches of concrete represented by a

    group of four consecutive test cubes shall include the batches from which

    samples were taken to make the first and the last cubes in the group of four

    together with all the intervening batches.

    (x) If only one cube result fails to meet the second requirement, then that result

    may be considered to represent only the particular batch of concrete from

    which that cube was taken provided the average strength of the group

    satisfies the first requirement.

    (xi) In the event of non-compliance with the testing plan, the Engineer

    may order the Contractor to carry out tests on the hardened concrete in the

    structure. These may include non-destructive methods or the taking of cored

    samples. Non-destructive loading tests shall be carried out in accordance

    with the requirements of BS 8110.

    Alternatively, if the structure or part of the structure fails to fulfil any

    requirement of the test, the Engineer may order replacement of the sub-

    standard concrete or any other action he deems necessary. The entire cost of

    testing and any remedial action shall be borne by the Contractor.

    1.19 Transport

    The concrete shall be transported from the mixer to the place of deposit in the works

    as rapidly as practicable and by means which will prevent segregation of the material

    or loss or contamination of ingredients. It shall be deposited as near as practicable in

    the final position to avoid rehandling or flowing. The concrete shall be conveyed by

    such vertical or inclined chutes that meet with the approval of the Engineer.

    1.20 Placing of Concrete

    (a) The concrete shall be placed in the positions and sequences indicated on the

    Drawings, in the Specification or as directed by the Engineer. Except where

    otherwise directed, concrete shall not be placed unless the Engineer is

    present and has previously examined and approved the positioning, fixing

    and condition of reinforcement and any other items to be embedded and the

    cleanliness, alignment and suitability of the containing surfaces of

    formwork.

  • MTECH CONSULTANTS

    S1/24

    (b) The maximum horizontal length of wall or floor in any one direction that

    shall be poured in one operation is 8.0 metres. The construction of walls

    and floor bays shall be carried out consecutively with a period of 7 days

    allowed between adjacent pours except where waterstops are provided when

    this period can be reduced.

    (c) Alternatively, a gap of 600 mm wide shall be left between adjacent pours

    and filled not earlier than 12 days after formation.

    (d) Where kickers are required, they shall be at least 100 mm high and they shall

    be constructed at the same time as the concrete on which they sit.

    (e) The concrete shall be deposited as nearly as possible in its final position

    without rehandling or segregation and in such a manner as to avoid

    displacement of the reinforcement, other embedded items or formwork.

    Wherever possible, bottom opening skips shall be used. Where chutes are

    used to convey the concrete, their slopes shall not be such as to cause

    segregation and suitable spouts or baffles shall be provided where necessary.

    Concrete shall not be dropped through a greater height than 2 metres except

    with the approval of the Engineer who may order the use of bankers and the

    turning over of the deposited concrete by hand before being placed.

    (f) Where pneumatic placers are used, the velocity of discharge shall be

    regulated by suitable baffles or hoppers where necessary to prevent

    segregation, or damage and distortion of the reinforcement, embedded items

    and formwork, caused by impact.

    (g) Concreting shall be carried out continuously between and up to

    predetermined construction joints specified below in one sequence of

    operation. In the case of slabs or beams designed to be monolithic with walls

    or columns, at least one day lapse shall be allowed after casting of the wall

    or column to allow for initial shrinkage before casting the beam or slab.

    (h) The surface of the concrete shall be maintained reasonably level during

    placing.

    (j) A record shall be kept on the Works site of the time and date of placing the

    concrete in each portion of the structure, and the reference numbers of the

    test cubes pertaining to batches of concrete in particular parts of the

    structure.

  • MTECH CONSULTANTS

    S1/25

    1.21 Placing Concrete in Water

    The placing of concrete under water will not be permitted except where agreed by the

    Engineer to be necessary. In placing concrete under water, it shall not be dropped

    into the water but shall be carefully placed in position by enclosing it in bags, or by

    means of bottom dumping bucket or tremie, or by continuous discharge through

    pipes leading from the mixer. Whichever method is proposed to use, full details

    shall first be submitted to the Engineer for his approval.

    The surface of the concrete deposited under water shall be kept as nearly as possible

    horizontal and no concrete shall be placed in running water or in water liable to

    disturbance by pumping. Placing shall be such as to require the minimum amount of

    spreading. Tamping to such an extent that segregation takes place shall be avoided.

    Sufficient time shall be allowed for the concrete to set before it is subjected to any

    form of loading and also to ensure that it shall suffer no damage from subsequent

    pumping or de-watering operations.

    1.22 Concreting in Adverse Weather

    No concreting will be allowed to take place in the open during storms or heavy rains.

    In places where such conditions are likely to occur, the Contractor is to arrange for

    adequate protection of the materials, plant and formwork so that the work may

    proceed under proper cover. Where strong winds are likely to be experienced,

    additional precautions to ensure protection from driving rain and dust shall also be

    provided. The Engineer may withhold approval of commencement of concreting

    until he is satisfied that full and adequate arrangements have been made.

    1.23 Concreting at Night or in the Dark

    Where approval has been given to carry out concreting operations at night or in

    places where daylight is excluded, the Contractor is to provide adequate lighting at

    all points where mixing, transportation and placing of concrete are in progress.

    1.24 No Partially Set Material to be used

    All concrete and mortar must be placed and compacted within 20 minutes of its being

    mixed. Unless otherwise approved, no partially set material shall be used in the work.

    When truck-mixed concrete is used, water shall be added under supervision either at

    the site or at the central batching plant as directed but, in no circumstances shall

    water be added in transit.

  • MTECH CONSULTANTS

    S1/26

    1.25 Concreting in High Ambient Temperature

    In hot weather and in places where the ambient shade temperature exceeds 32oC, the

    Contractor shall take measures in the mixing, placing and curing of the concrete.

    These shall be such as to ensure that the temperature of the mixed concrete at the

    time of placing shall include the shading of aggregates, water supply tanks and

    pipelines, from the direct rays of the sun, the spraying of aggregates with water,

    cooling of the mix constituents, machinery reinforcement and moulds and the

    reduction of transportation time to the minimum.

    During placing, suitable means shall be provided to prevent premature stiffening of

    the concrete placed in contact with hot surfaces. All concreting areas, formwork and

    reinforcement shall be shielded from the direct rays of the sun and sprayed with

    water when necessary.

    1.26 Compaction of Concrete

    The concrete shall be fully compacted throughout the full extent of the layer and

    shall be brought up in level layers of such depth that each layer can be easily

    incorporated with the layer below with the use of internal vibrators or by ramming. It

    shall be thoroughly worked against formwork and around any reinforcement or

    embedded items without displacing them.

    Except where otherwise permitted by the Engineer, concrete shall, during placing,

    be compacted by immersion vibrators having a frequency of at least 8,000

    cycles/minute and of a type to be approved by the Engineer. The vibrators shall be

    suitable for continuous operation. The vibrators shall be disposed in such a manner

    that the whole of the mass under treatment shall be adequately compacted at a speed

    commensurate with the supply of concrete from the mixers. They shall be operated

    by workmen skilled in their use and whom shall be additional to the labourers

    employed on placing and tamping the concrete. The internal vibrators shall be

    inserted and withdrawn slowly and at a uniform pace of approximately 100 mm per

    second.

    Compaction shall be deemed to be completed when cement mortar appears in a circle

    around the vibrator; over-vibration, leading to segregation of the mix must be

    avoided. The internal vibrators shall be inserted at points judged by the areas of

    mortar showing after compaction, with a certain allowance made for over-lapping,

    and they shall not be allowed to come into contact with the formwork or the

    reinforcement and shall be inserted at a distance of 75 mm from the former. The pan

    vibrators shall be placed on the surface of the concrete which shall have previously

    been tamped and levelled, leaving an allowance in height for the compaction, until

    cement mortar appears under the pan. The vibrator shall then be lifted and placed on

    the adjoining surface and this operations shall be repeated until the whole surface has

    been compacted. Alternatively, a vibrating screed spanning the full width of the

    surface may also be used.

    Vibration is not to be applied directly, or through the reinforcement, to sections or

    masses of concrete which have hardened or after the initial set has taken place.

    Vibration must not be used to make the concrete flow in the formwork so as to cause

    segregation.

  • MTECH CONSULTANTS

    S1/27

    1.27 Curing and Protection

    Concrete shall be protected during the first stage of hardening from the harmful

    effects of sunshine, drying winds, rain, running water or anything likely to

    interfere with the process of setting. The protection shall be applied as soon as

    practicable after completion of placing by covering the concrete surface with a layer

    of sacking, canvas, hessian, straw mats or similar absorbent material or a layer of

    sand, kept constantly moist by spraying with water as necessary for 7 days or such

    periods as may be directed by the Engineer. Other methods of preventing the water

    of hydration in the concrete from evaporating may be used if approved by the

    Engineer. In the case of floor surfaces, the hessian shall not be applied until the

    concrete is hard enough to resist marking.

    Where formwork cannot be removed within 12 hours of placing, the concrete shall

    be kept shaded from the direct rays of the sun and shall, where necessary, be

    sprayed with water to minimise the loss of moisture from the concrete.

    All work shall be protected from damage by shock or overload, including falling

    earth and construction loads not computed for.

    1.28 Concrete Cover

    Concrete cover to members shall be provided as indicated on the Drawings. Where

    not stated, concrete cover to main reinforcement shall not be less than that indicated

    in Table 1.12:

    The vertical distance between two horizontal main steel reinforcement bars or the

    corresponding distance at right angles to two inclined main steel reinforcement, shall

    not be less than 50 mm. This vertical distance shall be maintained by the use of

    spacer bars placed between the reinforcement.

    Table 1.12 Concrete Cover

    Structural member

    Concrete cover to main reinforcement

    Solid slabs (above ground)

    25 mm or diameter of bars, whichever is greater

    Main columns 40 mm

    Suspended ground floor slabs 35 mm

    Beams and ribs (above ground) 35 mm or diameter of bars, whichever is greater

    Ground beams 45 mm

    Pile caps 50 mm

  • MTECH CONSULTANTS

    S1/28

    1.29 Construction Joints

    The Contractor shall submit details of his proposals for construction joints and

    concreting programme to the Engineer for approval. The Contractor is to allow for

    working beyond the ordinary working hours where necessary in order that each

    section of concrete may be completed without any lapse while the work is in hand.

    The number of construction joints should be kept as few as possible consistent with

    reasonable precautions against shrinkage.

    All construction joints are to be formed square to work. Keyways are to be formed in

    all horizontal and vertical construction joints except where ordered to be omitted by

    the Engineer.

    Where work is resumed on a surface which has set, the whole surface shall be

    thoroughly roughened or scrabbled with suitable tools so that no smooth skin of

    concrete that may be left from the previous work is visible. These roughened

    surfaces shall be thoroughly cleaned by compressed air and water jets or other

    approved means and brushed and watered immediately before depositing concrete. If

    so ordered, roughened surface shall be covered with cement mortar (1:2 mix) prior to

    placing the new concrete.

    1.30 Joints in Concrete

    Contraction joints where specified, shall be formed as deliberate planes of

    discontinuity in the concrete structure. They shall be of a key profile with or

    without continuity in reinforcement.

    Expansion joints shall be formed in the same way as contraction joints but in

    addition, "flexcell" compressible filler as manufactured by Fosroc Expandite Pte Ltd

    or similar approved shall be supplied and placed in the joints to provide freedom for

    two adjacent concrete slabs or blocks to expand. The exposed edges of the joints

    shall be sealed with an approved polysulphide rubber sealing compound to BS 4254.

    Where a designed joint occurs in a water retaining structure, or where

    otherwise ordered, the joint shall be made watertight by the provision of a

    continuous waterstop strip of copper, rubber or plastic (such as Poly-Vinyl-Chloride,

    P.V.C.) as specified, fixed across the joint where shown on the drawings. Special

    care shall be taken to ensure that the concrete is well worked against the embedded

    parts of the strip and is free from honeycombing. Precautions are to be taken to

    protect any projecting portions of the strips from damage during the progress of the

    Works and in the case of rubber and plastic, from light and heat.

    In the case of copper waterstop where direct bituminous painting shall be applied to

    the lips of the loop and the loop shall be fitted with a bituminous compound, these

    applications shall be made before the strip is buried in the concrete.

  • MTECH CONSULTANTS

    S1/29

    1.31 Blinding Concrete

    Several days before concrete is to be deposited on a foundation on the ground, a

    blinding of concrete grade 15 of 75 mm minimum thickness, shall be placed over the

    ground below the underside level of the reinforced concrete to form a hard even

    surface on which to construct the latter. Where other details are indicated in the

    Drawings, this Clause shall not apply.

    1.32 Mass Concrete Backing to Masonry or Brickwork

    Mass concrete backing to masonry of brick facing shall be mixed slightly wetter than

    that mixed for placing against timber forms. Before any concrete is placed, the

    mortar joints in the facework shall have thoroughly hardened, and the back of the

    facing must be thoroughly wetted. The concrete shall be carefully tamped round any

    ties or bond stones, and mortar from the concrete shall be carefully worked into the

    open joints in the back of the facework.

    1.33 Formwork

    (a) General

    The formwork shall be constructed of sound, well-seasoned timber or other

    approved material of such quality and strength as will ensure complete

    rigidity throughout the placing, ramming, vibration and setting of the

    concrete. It shall be sufficiently tight to prevent loss of liquid from the

    concrete.

    Where formwork is not provided with special lining as specified in Clause

    (b) below, the faces in contact with concrete shall be planed smooth, true to

    alignment and free from surface imperfections and the joints between boards

    shall be tongued and grooved or caulked with tight fitting fillets recessed into

    adjacent boards and covering the joint. Internal ties or struts shall be of

    metal and capable of removal without injury to the concrete. No part of any

    metal tie or spacer remaining permanently embedded in the concrete shall be

    nearer than 50 mm to the finished surface of the concrete. Construction

    details shall be arranged to permit easy removal, and wedges and bolts shall

    be employed whenever possible in preference to nails.

  • MTECH CONSULTANTS

    S1/30

    (b) Cleaning and Treatment of Forms

    Before concrete is deposited, the forms shall be thoroughly cleaned and freed

    from sawdust shavings, dust, mud or other debris by hosing with clean water.

    Temporary openings shall be provided in the forms to drain away the water

    and rubbish. Unless otherwise directed by the Engineer, the inside surface of

    forms shall, before placing of the reinforcement, be coated with an approved

    mould oil or other release agent, care being taken at all times thereafter to

    keep the reinforcement free from any such material. There shall be no excess

    coating material in the form prior to concreting. All formwork shall be

    inspected by the Engineer after preparation and immediately prior to

    depositing concrete and no concrete shall be deposited until approval of the

    formwork has been obtained from the Engineer.

    (c) Removal of Formwork

    Formwork shall be removed without such shock or vibration as would

    damage the concrete. The minimum striking times shall be as listed in Table

    1.13 below. The times are given in days, where a day is to be of 24 hours

    duration.

    Table 1.13 Minimum striking times

    Location of forms removed

    Minimum Striking Times for O.P.C.

    ( Ordinary Portland Cement ) concrete (days)

    Slabs soffits (structural props left in)

    5

    Beam sides (greater than 1200 mm lift)

    (less than 1200 mm lift)

    3

    1

    Beam soffits (structural props left in)

    6

    Slab structural props

    10

    Beam structural props

    21

    Columns and walls (unloaded)

    3

    The foregoing Table is given as a guide for Ordinary Portland Cement (OPC). The

    Engineer may at his discretion alter the above times if he considers such adjustment

    to be necessary.

  • MTECH CONSULTANTS

    S1/31

    1.34 Forms for Exposed Concrete Surfaces

    Forms for all permanently visible concrete surfaces shall be such as to ensure that

    surface is of the correct shape, line and dimensions. Where rough formwork is

    specified, no surface irregularities greater than 10 mm shall be allowed and, in the

    case of reinforced concrete, the full cover to steel shall be maintained. Where

    wrought formwork is specified, the forms shall be such as to produce a smooth and

    even surface free from perceptible irregularities, and tongued and grooved; planed

    boards or plywood or steel forms shall have their joints flush with the surface. The

    full cover to reinforcement steel shall be maintained. The Contractor shall make due

    allowance for the renewal and /or repair of shuttering for which more than one use is

    intended.

    1.35 Forms for Non-exposed Concrete Surfaces

    Where the finished surface of concrete is not to be permanently exposed, the forms

    may be constructed of plain, butt-jointed sawn timber unless otherwise directed by

    the Engineer. In mass concrete, surface irregularities may be permitted but in

    reinforced concrete construction, the surface shall be true and the full cover to the

    reinforcement shall be maintained at all points.

    1.36 Surface Defects

    As soon as the formwork has been removed, but after inspection by the Engineer,

    honey-combing or small holes in faces shall be filled with cement mortar composed

    of equal parts of Portland Cement and sand. However, if in the Engineer's opinion,

    any defects cannot be made good by touching up, he may order the replacement of

    the work, which will be at the Contractor's own cost.

    1.37 Openings in Reinforced Concrete

    All necessary openings for pipes, fittings outlets, etc., shall be formed and the corners

    or edges trimmed with high tensile bars to approval.

    1.38 Fixings and Cavities in Concrete

    The Contractor shall ascertain from the drawings or from sub-Contractors or from

    elsewhere, particulars of all bolt and other fixings, and of all openings, holes,

    pockets, chases, recesses and other cavities so that before the placing of the

    concrete, all bolts, boxes and fixings shall be in place. No holes shall be cut after

    the concrete has been placed without express authorisation from the Engineer.

  • MTECH CONSULTANTS

    S1/32

    1.39 Concrete Finishes

    (a) General

    The faces of concrete work shall have the finishes indicated on the Drawings

    if these are provided. The finished surface of all concrete work shall be

    sound, solid and free from honeycombing, protuberances and blemishes. No

    plastering of imperfect concrete faces will be allowed and any concrete that is

    defective in any way is to be cut out and replaced to such depths and be made

    good in such manner as the Engineer may direct at the Contractor's own

    expense. The cavities left by formwork fixing devices are to be made good by

    completely filling the hole with mortar, which shall be such as to dry out with

    the same colour as the adjacent concrete.

    (b) Fine Finish

    When a fine finish is specified, the surface of the concrete shall, immediately

    following the removal of the forms, be wire brushed to remove any surface

    imperfections or irregularities. It shall then be well brushed with water and

    rubbed down to a smooth finish by means of a carborundum block. Where

    directed, the rubbing down shall be preceded by the application of a Portland

    Cement wash and the surface thus treated shall be carefully protected from

    rapid drying out by suitable means.

    (c) Concrete Surfaces without Formwork

    (i) Where, on an upward facing horizontal or near horizontal surface

    which does not require formwork, no particular finish is called for,

    the surface shall be that produced by the proper placing and

    compaction operations without further labours.

    (ii) Where a 'fair surface' is specified, it shall be obtained by screeding.

    This shall be done immediately after compaction of the concrete, by

    the slicing and tamping action of a screed board running at the top

    edges of the formwork, or on accurately set screeding guides, to give

    a dense concrete skin, true to line and level.

  • MTECH CONSULTANTS

    S1/33

    (iii) Where a 'fine surface' is specified, it shall be obtained by first

    screeding the concrete as described in the preceding sub-clause then

    leaving it until the concrete has stiffened and the film moisture has

    disappeared. Floating shall then be applied with a steel or wooden

    float to produce a 'glossy' surface or a 'sand paper' surface as

    required. Working should be kept to a minimum compatible with a

    good finish. The surface shall be true to the required profile to fine

    tolerance. Wherever necessary, a properly constructed overhead

    cover shall be erected before the work is commenced to prevent the

    finished surface from being marked by raindrops or dripping water.

    (d) Workmen

    The finish to the exposed concrete surfaces shall only be carried out

    by skilled workmen experienced in this class of work. The Engineer

    may order the removal of any workman whom he may consider

    insufficiently experienced or skilled for this class of work and require

    the substitution with workmen of the required standard.

    (e) WireBrushed Finish

    Immediately after removal of the forms the surface of the concrete

    shall be well scrubbed down by means of stiff wire brushes and water

    to remove the cement from the surface and expose the aggregate.

    (f) Bush Hammered Finish

    Not less than 3 weeks (for Ordinary Portland Cement concrete) after

    the concrete has been placed the exposed surface shall be bush-

    hammered to remove the cement from the surface and expose the

    aggregate. Bush hammers shall be of an approved type, and they shall

    be worked to within 12 mm of all corners and arises, the treatment of

    the remaining 12 mm borders being hand finished similar to that of

    the adjoining bush-hammering. Bush hammers shall be kept

    perpendicular to the surface being worked and care shall be taken to

    ensure that only the surface mortar and the irregular projections of the

    aggregate are removed without any fracturing or loosening of the

    portions left embedded. As the bush-hammering is completed, the

    surface so treated shall be washed with water and scrubbed down with

    a stiff brush. All finished surfaces shall be of an even and uniform

    appearance with the exposed aggregate clean and free from film.

  • MTECH CONSULTANTS

    S1/34

    (g) Specimen Panels of Concrete

    Where required by the Engineer, the Contractor shall construct and

    treat specimen panels of concrete to the required finish, in order to

    satisfy the Engineer as to the suitability and efficiency of the

    proposed method of treatment.

    1.40 Surface Tolerances

    The acceptable tolerances on concrete surfaces measured in millimetres shall be as

    listed in Table 1.14.

    Table 1.14 Acceptable tolerance on concrete surfaces.

    Type of

    structure

    Type of irregularity

    Sawn

    Formwor

    k

    Faced

    formwork

    Tamped

    formwork

    Float

    Finish

    Buried

    concrete

    Departure in alignment

    and grade

    +50

    -10

    -

    +10

    -

    Variations in cross

    sectional dimensions

    +10

    -5

    -

    +10

    -5

    -

    Deviation from

    alignment checked

    against a 3m straight

    edge

    +10

    -

    +10

    -

    Exposed

    concrete and

    internal

    surfaces of

    sewer culverts

    Departure in alignment

    and grade

    -

    +10

    +10

    +5

    Variations in cross

    sectional dimensions

    -

    +10

    -5

    - +10

    -5

    Deviation from

    alignment checked

    against a 3m straight

    edge

    -

    +5

    +5

    +5

  • MTECH CONSULTANTS

    S1/35

    1.41 Tests on the Structures

    The Engineer shall instruct the Contractor to make a loading test on the works or any

    part thereof if in the Engineer's opinion, such a test is necessary.

    If the test so instructed to be made solely or in part for the reason that the

    site- made concrete cubes fail to attain the specified strength, the test shall be made at

    the Contractor's own expense. If the test instructed to be carried out is because of

    one or more circumstances attributable to alleged negligence on the part of the

    Contractor, the Contractor shall be reimbursed for the cost of the test if the result

    thereof is satisfactory.

    If the test be instructed to be made for any reason other than the foregoing, the

    Contractor shall make the test and shall be reimbursed for all costs relating thereto,

    irrespective of the results of the tests.

    For the purpose of testing floors, roofs and similar structures and their

    supports, the test load shall be equivalent to one-and-a-quarter times the live load for

    which the Works or part thereof to be tested has been designed. The test load shall

    not be applied within twenty-eight days of the completion of placing of the concrete

    in the part of the Works to be tested, and the latter shall be unsupported during the

    test by the shuttering or other non-permanent support. The test shall be made as

    instructed.

    For test on a floor, roof or similar construction, the result shall be deemed to be

    satisfactory if upon removal of the load the residual deflection does not exceed one

    quarter of the maximum deflection occurring during the second test.

    If the result of the test is not satisfactory, the Engineer shall instruct that the part of

    the Works concerned shall be taken down or cut out and reconstructed to comply

    with this Specification, or that other measures shall be taken to make the Works

    secure. If in accordance with this Specification the Contractor is liable to conduct the

    test at his own cost, he shall also at his own cost, take down or cut out and

    reconstruct the defective work or shall execute remedial measures as instructed.

    1.42 Preparation of Ground below Permanent Construction

    Plain concrete in foundations or site concrete shall be placed in direct contact with

    the bottom of the excavation, the concrete being deposited in such a manner as not to

    be mixed with the earth. Alternatively, when directed by the Engineer or shown on

    drawings, hardcore and/or sand blinding shall be used, or a layer of building paperis

    specified.

  • MTECH CONSULTANTS

    S1/36

    1.43 Temperature Control ( For structural slab or member with thickness exceeding 1.2m)

    (a) The contractor shall take steps to limit the temperature of the concrete placed as

    follows

    (i) Not exceeding 32C at the time of placing.

    (ii) Not exceeding 78C during hydration at any time up to 14 days after

    concreting.

    (iii) Not exceeding 20C as a difference between the most exposed face of the

    concrete and the mid-depth of the pour after concreting.

    Concrete which fails to comply with (i) shall not be placed in slab. Concrete which

    fails to comply with (ii) and (iii) anywhere in their length/volume shall be considered

    as defective work.

    A minimum of four (4) sets of thermo-couples consisting of 5 Nos. per set for

    recording concrete temperature shall be placed in advance in panel to cast. The

    thermo-couple shall be secured in positions by non-conductive material such as pvc

    and kept from coming into contact with steel reinforcement bars. Each set of thermo-

    couples is to be arranged in vertical row with the topmost and bottommost thermo-

    couples being placed within a cover of 25 mm. One thermo-couple shall be located

    at mid-depth of the slab and the remaining two placed at 1/4 and 3/4 depth of the slab

    thickness respectively.

    The concrete temperature shall be recorded at intervals not exceeding two (2) hours

    for the first 24 hours and thereafter at 6 hours interval or at such other intervals as

    maybe required by the Engineers for a minimum period of fourteen (14) days or until

    a differential temperature of 10C or less is attained.

    The Contractor shall submit at the time of tender, the methods he proposes to use to

    achieve the concrete temperature limits as stated above.

    Protection shall be applied as soon as practicable after completion of placing by a

    layer of waterproof fabric keep in contact with the concrete.

    (b) In order to comply with temperature limitation requirements, advantage shall

    be taken of the insulation value of any timber formwork that may be in use

    by allowing it to remain for sufficient time to ensure the peak of temperature

    is passed before removal. Slab surfaces should be protected as soon as

    practicable after the initial set has taken place by covering the surface with a

    0.15mm thick polythene sheet with watertight joints upon which 100 mm

    thick polythene foam boards are placed.

  • MTECH CONSULTANTS

    S1/37

    (c) Test Blocks for Testing Thermal Characteristics of Concrete

    Before placing concrete, the Contractor shall ascertain the thermal characteristics of

    the cement and aggregates to be used from which he shall calculate the likely

    maximum temperature of the concrete during hydration. The Contractor shall submit

    the calculations to the Engineers for approval. The Contractor shall then construct

    two test blocks of 1.2m x 1.2m x 2.0m (D) each. The blocks shall be reinforced on

    the top and bottom face with 25mm dia. high yield reinforcing bars at 200 mm in

    each direction. The clear cover to the bars shall be 50 mm.

    The materials used in making concrete for the test blocks, reinforcement, formwork

    and materials used for protecting the top surfaces of the test blocks during curing

    shall be those intended for use in placing the slab concrete. The test blocks shall be

    cooled and insulated in the same manner as the member to be cast.

    The temperature of the concrete at the time of placing shall not exceed 32 degrees

    Celcius. Thermometers shall be installed in the concrete near to the surface at the

    centre of each face and one shall be placed centrally in the block. Temperatures shall

    be recorded at initially two hourly intervals for a period of 48 hours and thereafter at

    eight hourly interval for a further period of at least 12 days for each block.

    Six (6) 150 mm test cubes shall be prepared during the placement of concrete for

    each block with two for testing at 7 days and four for testing at 28 days.

    The test blocks shall be examined at regular intervals for potential cracks and a

    careful note shall be made of any cracks found during the period leading to the

    testing of the test cubes.

    The concrete mix shall be considered satisfactory if for each block the following

    conditions are met : -

    (i) The average strength of the four test cubes at 28 days exceeds that specified

    for preliminary and trial mix tests by at least 5 N/mm.

    (ii) The maximum temperature during hydration does not exceed 78 degrees.

    Celsius and the difference in temperature between any face of the test block

    and its centre does not exceed 20C at any time.

    (iii) The nature of any cracks appearing in the test block is such that, in the

    opinion of the Engineer, the cracks do not constitute a potential source of

    harm if they were to occur in the concrete for the permanent works.

    If condition (i) above for cube strength is not fulfilled the Contractor shall redesign

    the concrete mix, construct further test blocks and repeat the testing as specified.

  • MTECH CONSULTANTS

    S1/38

    If condition (ii) above is not fulfilled or if under condition (iii) the Engineer is of the

    opinion that the cracks as noted are potentially harmful the Contractor shall propose

    additional measures to comply with conditions (ii) and (iii) at his own cost.

    If the Engineer so requires the Contractor shall construct further test blocks to

    demonstrate the efficacy of the measures which are to be incorporated before placing

    concrete in slab.

    (d) Casting of slab using the method of temperature control

    Prior to the casting of slab, the Contractor shall submit method statements relating to

    the following items for the approval of the Engineer: -

    (i) Details and results of the temperature trials.

    (ii) Mix proportions of the concrete mix using minimum cement content or

    replacement of cement with silica fume including all admixtures used to

    achieve a slump of not less than 200 mm with minimum segregation and

    bleeding and the specified concrete placing temperature.

    (iii) Plant, equipment (including standby equipment) and manpower that are required for each pour.

    (iv) Sources of supply of concrete and alternative sources of supply of these

    items in the event of total breakdown.

    (v) Time and duration of each pour.

    (vi) Traffic flow pattern of concrete supply trucks within the Site.

    (vii) Concrete placing and compaction.

    (viii) Progressive removal of bleeding water from the wet concrete.

    (ix) Thermal insulation to formed and exposed surfaces.

    (x) Temperature monitoring and record, including layout and setting out of

    thermo-couples and the type of electronic thermometer capable of converting

    directly into degrees centigrade the potential difference generated by the

    thermo-couples.

    (xi) Curing.

    (xii) Layout and preparation of construction joints. The construction sequence

    should be planned to minimise trapped bays (i.e. bay which has adjacent

    sides or two opposite sides cast against massive hardened concrete with

    continuous reinforcement across each interface).

  • MTECH CONSULTANTS

    S1/39

    (xiii) Measures to be taken in emergency situations (e.g. rain).

    (xiv) Other information relating to the casting of the slab which may be required

    by the Engineer.

    1.44 Precast Concrete

    (a) General

    The concrete as cast in one piece shall be placed in one operation. No pieces shall be

    removed from the mould or erected until sufficiently matured to ensure that no

    damage shall be done to the piece. A piece shall be suspended or supported only at

    the points described on the working drawings or elsewhere. A piece that is cracked or

    damaged during, before or after erection shall be removed from the works from the

    works and replaced by the Contractor at his own expense. Pieces shall be bedded or

    fixed in their permanent positions as instructed.

    (b) Materials

    All precast concrete and revetment slabs shall satisfy BS 368 especially Tables 2 &

    3.

    All precast pipes shall conform to SS 183.

    All precast kerbs and channels shall satisfy BS 340.

  • MTECH CONSULTANTS

    S2/1

    SECTION 2 - STRUCTURAL STEELWORK AND METALWORK

    1. STRUCTURAL STEELWORK

    1) GENERAL

    1.1 Definitions

    (a) Shop Drawings

    These refer to drawings showing all necessary information to fabricate and erect the

    structural steelwork and structural steel decking including drawings showing the

    dimensional layout of the steel structure and which correlate the piece markings with

    the location in the structure.

    (b) Quality Assurance/Quality Control

    The specification describes an acceptable level of quality to be achieved by the

    Contractor, and it describes the tests that the Contractor shall carry out to

    demonstrate that he has achieved the required quality.

    (c) Independent Testing Agency

    In addition, an independent organisation (if required under the project) separately

    appointed by the Employer and known as the Independent Testing Agency (ITA),

    shall carry out certain tasks to ensure that:

    i) The Contractor's proposed methods of working are likely to produce

    acceptable work.

    ii) Finished items and assemblies conform with the Specification.

    The duties of the ITA include the carrying out of non-destructive testing in addition

    to that carried out by the Contractor.

    1.2 Substitutions

    No substitutions to the Contract Specification or Contract Drawings may be made

    without approval.

    1.3 Commencement of The Work

    No item of work shall be commenced until the results of any related preliminary test

    required by the Contract Specification have been approved.

    1.4 Code of Practice

    Comply with BS 5950 and this section of the Contract Specification. In cases of

    conflict, the more stringent will take precedence.

  • MTECH CONSULTANTS

    S2/2

    1.5 Connection Details

    Design and detail those connections which are not shown on the Contract Drawings.

    The type of joint is to follow the form of the typical details shown on the Contract

    Drawings and is to be designed to carry loads which shall be specified. All details

    designed by the Contractor are to be substantiated by full calculations certified by a

    Professional Engineer registered in Singapore.

    1.6 Temporary Works

    Design, fabricate, erect and remove all temporary work. The Contractor shall engage

    a Professional Engineer registered in Singapore for the design and supervision of the

    erection for all temporary works and he shall be responsible for ensuring the safety

    and stability of the structure during all stages of the construction.

    1.7 Construction Information

    (a) Fabrication

    Provide the following information at least 8 weeks before commencing

    fabrication.

    i) Complete and coordinated Shop Drawings.

    ii) Calculations to substantiate connections detailed

    by the Contractor.

    iii) Detailed method statements for fabrication.

    iv) Details of welding procedures in accordance with

    BS 5135 for all welds, including tack and sealing welds.

    v) Details of proposed shop inspection system and non-

    destructive testing arrangements.

    (b) Erection

    Provide the following information at least 8 weeks before commencing

    erection.

    i) Detailed method statement for erection, including type of crainage.

    ii) Detailed drawings and calculations for all temporary works.

    iii) Detailed of proposed site inspection system.

  • MTECH CONSULTANTS

    S2/3

    (c) As-Built Drawings

    Provide as-built drawings which show the work as finally fabricated and

    erected.

    1.8 Programme

    (a) Detailed Programme

    Provide a detailed programme to show the planned timing of the various

    items of work to be done, including:

    i) Preparation and submission of construction information.

    ii) Order and delivery of materials

    iii) Fabrication

    iv) Application of protective coatings

    v) Transport to site.

    vi) Erection

    (b) Inspection and Testing

    Provide a detail programme and include in the programme the necessary time

    for all procedural trials, inspection and testing, and trial assemblies if

    required. The Contractor shall also make allowance for time required by ITA

    to carry out cross-checking of Contractor's testing. The average rate of ITA

    testing may be assumed to be one ITA test for every 20 Contractor tests.

    (c) Progress

    Arrange the programme so that actual progress can be monitored against

    each item.

    2) QUALITY CONTROL

    Provide a Quality Manual to the satisfaction of the Engineer and as laid down to the

    requirements of Quality Assurance Programs

  • MTECH CONSULTANTS

    S2/4

    3) MATERIALS

    3.1 Steelwork

    (a) The Universal Section Steels and Hollow Section Steels to be used shall be of the best quality and conform to the respective British Standards Specification for

    such material.

    (b) Every section shall be straight and true to its profile.

    (c) Where a section is to be cut to an exact length, it shall be cold sawn to within +3.2 mm of that length.

    3.2 Splicing

    Except where specifically instructed by the Engineer in writing, every section shall

    be in one length throughout. If and when extension of particular sections are so

    instructed, the extension piece shall be in a single length to be determined by the

    Engineer and not made up of two or more short pieces. The Contractor shall

    fabricate the splice by welding in accordance with a detail drawing to be provided by

    the Engineer. Such joint will be designed to transmit the full strength of the steel

    section in shear, bending and bearing.

    3.3 Bolts, Nuts and Washers

    Mild steel bolts and nuts shall comply with the requirements of BS 5950 and either

    BS 916 or BS 2708 or BS 4190.

    Structural quality high tensile steel bolts and nuts shall be manufactured from

    material as specified in BS 5950 and BS 4360 Grade 50B.

    Special quality high tensile steel bolts and nuts shall comply with the requirements of

    BS 5950 and either BS 1768 or BS 1083 or BS 3692.

    High strength friction grip bolts, nuts and washers shall comply with the

    requirements of BS 4395 and BS 4604.

    Plain and tapered washers, other than for high strength friction grip bolts, shall

    comply with the requirements of BS 5950 and BS 4320.

    High strength friction grip bolts are to be of the load indicating type. All bolts, nuts

    and washers shall be cadmium plated to a minimum thickness of 0.005 mm. Load

    indicating washers shall be standardised.

  • MTECH CONSULTANTS

    S2/5

    4) WELDING

    Welding shall be carried out in accordance with BS 5950, BS 856, BS 2642 and BS

    639 as applicable for the type of steel used, by an electric arc process using

    equipment of adequate capacity for the conditions of the work.

    All welding shall be carried out by fully trained and experienced welders. In this

    connection, the Engineer may request the production of Welders Test Certificates.

    Surfaces to be welded shall be free from loose scale, rust, grease, paint or other

    deleterious material that might impair the quality of the weld.

    Welding should be done in the workshop wherever possible.

    5) PLANT AND EQUIPMENT

    The suitability and capacity of slings, lifting appliances and blocking and of all other

    plant and equipment used for erection shall be to the satisfaction of the Engineer.

    6) SETTING OUT

    The positioning and levelling of all steelwork, the plumbing of stanchions shall be in

    accordance with the approved drawings and to the satisfaction of the Engineer.

    7) SAFETY DURING ERECTION OF SHORING

    During erection, the work shall be securely bolted or otherwise fastened and if

    necessary, temporarily braced to provide safety for all erection stresses and

    conditions, including those due to erection equipment and its operation. Neither

    permanent bolting nor welding shall be done until proper alignment has been

    obtained.

    8) FABRICATION

    As much as possible of the work shall be fabricated in the Specialist Fabricator's

    workshop. Four clear days' notice shall be given to the Engineer of fabricated work

    being ready for inspection at the workshop.

    The steelwork shall be fabricated to a pre-camber so that the dimensions required on

    completion of erection are obtained. The instructions for forming the pre-camber that

    are given on the Drawings shall be followed.

    All parts such as main stanchion caps and bases and butt joints shall be

    accurately machined so that the whole areas of the section shall make the required

    contact. The bases shall be truly at right angles to the axes of the stanchions in all

    planes.

    The ends of all joists, beams and girders shall be truly square where required, and

    joist flanges shall be neatly cut away and notched where necessary; the notches

    being kept as small as possible and well radiused.

    Cutting may be effected by shearing, cropping or sawing. Gas cutting may only be

    used when specifically authorised in writing by the Engineer. The edges of all

  • MTECH CONSULTANTS

    S2/6

    plates shall be perfectly straight and fair throughout. Sheared members shall be free

    from distortion and shall have the edges dressed to a neat and workmanlike finish.

    Except where suitable templates are used, holes through more than one

    thickness of material shall be drilled after the members are assembled and tightly

    clamped together. If the holes are punched separately before assembly, the holes

    shall be punched 4 mm less in diameter than the required size and reamed after

    assembly to the full diameter. The maximum thickness of materials punched shall

    not be greater than 16 mm.

    All members shall be straight, free from twists, cracks, flaws, laminations,

    rough, jagged and imperfect edges and other defects.

    Holes for bolts shall not be formed by a gas cutting process, except with specific

    approval from the Engineer.

    9) HIGH STRENGTH FRICTION GRIP BOLTS

    High strength friction grip bolts to BS 4395 shall be used in accordance with BS

    4604 Part 1 with modifications and additions given below.

    All bolts shall be provided with hardened steel washers under both head and nut.

    The washers shall be suitably tapered where the angle between the bolt axis

    and the steel bearing surface is outside the limit of 90o + 1o.

    Each bolt shall be tightened to its specified proof load and the required induced

    tension shall be indicated by the compression of protrusions either on the bolt head

    or on a washer. Where the load is indicated by protrusion or a washer, such

    washer may replace a flat washer under the bolt head but in places where it is

    necessary to place the indicating washer under the nut then an additional facing

    washer shall be supplied, suitably heat-treated to the same hardness as the bolt.

    Before any bolt of a group is finally tightened, all bolts of the group shall be part

    tightened in the correct sequence by applying a bedding torque as given in

    Table 1 below. After the bedding torque has been applied to each bolt, the bolts

    shall be tightened in the correct sequence until the gap under the load indicating bolt

    head or washer has been reduced to a dimension determined by the Engineer. If for

    any reason a bolt is slackened or removed after full tightening, it must be replaced by

    a new bolt.

  • MTECH CONSULTANTS

    S2/7

    Table 1 Bedding torque for high strength friction grip bolt

    Preliminary tightening of nuts

    Nominal diameter of bolt Bedding torque (Nm)

    (mm) Minimum Maximum

    20 122 244

    22 170 340

    25 237 474

    28 373 746

    32 530 1060

    10) HOLDING-DOWN BOLTS AND OTHER FIXINGS.

    Holding down bolts and other fixings are to be set out accurately, with templates

    provided if necessary, by the Contractor in accordance with the Engineer's

    and Specialist's drawings, and when cast in shall be protected from any damage or

    deterioration.

    Holding down bolts shall be cast in to the dimensions shown on the Engineer's

    drawings, and the Contractor shall ensure that the projecting ends of the bolts have

    freedom for horizontal movement within the hole. The projecting ends of bolts shall

    be well greased and wrapped in sacking which shall remain in position until the

    commencement of steelwork erection.

    Prior to the delivery of steelwork for erection, the Contractor shall check concrete

    bases or other seating for steelwork in respect of level, setting out, projection and

    full degree of adjustment of holding down bolts or other fixings and ensure they

    are in accordance with the Engineer's and/or Contractor's drawings.

    The Contractor shall remedy any discrepancies or inaccuracies to the satisfaction of

    the Engineer. No modification of the steelwork or fixings, bending of holding down

    bolts, or the use of an excessive number of washers to accommodate errors in

    position and projection of bolts or fixings shall be made except with the written

    permission of the Engineer.

  • MTECH CONSULTANTS

    S2/8

    11) GROUTING OF STEEL BASES AND CONCRETE ENCASURE OF

    STRUCTURAL STEELWORK.

    After final levelling and alignment of the steelwork, grouting and encasing shall be

    carried out by the Contractor as follows:

    (a) In all cases the grouting space shall be thoroughly clean and temporary

    shuttering shall be provided if necessary to enable the requisite pressure head

    to be sustained.

    (b) Grouting of stanchion bases and bearings of beams and girders.

    (c) Grouting shall be laid in strict accordance with the manufacturers instructions

    and shall be of a non-shrink type or Engineer approved equivalent.

    12) PROTECTION OF STEELWORK AGAINST CORROSION

    12.1 General

    Except as otherwise specified, the relevant clauses of the British Code of

    Practice, CP 2008 : 'Protection of Iron and Steel Structures from Corrosion'

    shall apply.

    On the placing of this Contract and well before the commencement of the

    protective coating of any steel, there shall be consultations between the

    Engineer and the Contractor to agree inspection methods, tools and timing.

    All shop treatment shall be carried out in an approved, weatherproof

    structure under dry, clean conditions. Open fires, or other heating methods

    producing sulphur dioxide shall not be used.

    Notwithstanding the 36-hour curing periods specified herein, no treatment

    shall be applied until the Engineer is satisfied that the surface is clean and

    dry, and that any previous treatment is satisfactory and has hardened

    adequately. When a surface has been approved, it shall be painted

    immediately.

    All paints are to be applied by techniques to produce a surface of uniform

    colour and texture. Particular importance shall be paid to the works finishing

    coat. All tools, solvents and plant used shall be such as to secure the best

    possible results, and shall be maintained in good condition both in use and in

    storage. Solvents used for the removal of oil, grease and dirt shall be non-

    injurious to both metal and paint, and any excess shall be completely cleaned

    off immediately after use.

  • MTECH CONSULTANTS

    S2/9

    Every subsequent coat applied to any surface shall be of a hue different from

    that preceding such that the coverage of each coat is easily visible.

    Throughout the protective treatment, transport, site storage and erection, the

    lifting and handling methods shall be such as to secure the absolute

    minimium of damage to paint work. Such damage as does occur shall be

    made good when so directed by the Engineer, to his entire satisfaction.

    Touching up to the correct thickness must be carefully carried out to avoid

    high spots in the system.

    12.2 Preparation of surfaces to receive paint

    CANCELLED

    12.3 Treatment of Surfaces

    CANCELLED

  • MTECH CONSULTANTS

    S2/10

    12.4 Treatment to be carried out on Site

    Prior to erection, all steelwork is to be thoroughly washed down and cleaned.

    Any handling or transit damage to the shop treatment and any damage caused

    by erection shall be made good as soon as possible.

    Damaged areas of paint work shall be cleaned to bare metal and the edges of

    the undamaged paint levelled with sand paper. The full specified painting

    system shall then be re-applied and the new paint shall overlap the existing

    paint by at least 50 mm all round the affected part.

    All contact surfaces shall be thoroughly wire brushed and cleaned of all

    foreign matter immediately prior to being brought together. Special care

    shall be taken to remove all oil, grease, paint, etc., from surfaces joined by

    friction grip bolts.

    After tightening, bolt heads, nuts and washers shall be cleaned and externally

    exposed surfaces painted with two coats of primer and one coat of finishing

    enamel.

    Surfaces to be encased in concrete shall be thoroughly cleaned of all loose

    paint and rust, oil and grease immediately prior to concreting and left

    untreated, except that a strip 30 mm wide from each edge shall be treated as

    for the adjacent steelwork.

  • MTECH CONSULTANTS

    S2/11

    12.5 Standard of finish

    The Contractor shall ensure that the whole of the paint work is in a good,

    clean condition, and of uniform appearance on completion of the Contract.

    Unless otherwise agreed by the Engineer, each coat of paint shall be applied

    by the method specified and recommended by the manufacturer to produce a

    continuous film of paint of uniform and even thickness in the dry condition

    of the applied paint. In the case where no such recommendation has been

    given, the Contractor shall refer to the Engineer for the approved method of

    application.

    The total dry paint film thickness of the various systems shall not be less than

    the specified values. The paint film thickness shall be measured when dry,

    using Elcometer or other instruments approved by the Engineer.

    In order to obtain dry film thickness specified, the contractor shall ensure

    that the coverage rate given by the paint manufacturer will enable this

    thickness to be attained.

    12.6 Storage of Painted Steelwork

    Painted fabricated steelwork which is to be stored prior to erection shall be

    laid out or stacked in an orderly manner that will ensure that no pools of

    water or dirt can accumulate on the surfaces. Suitable packings shall be laid

    between the layers of stacked materials. Where a cover is provided, it shall

    be well ventilated. Any steelwork on which the application of the shop

    treatment has commenced, shall be fully protected from external atmospheric

    conditions, until completion of the system and curing period previously

    specified.

    12.7 Paint

    All paints shall be obtained from suppliers approved by the Engineer. Unless

    otherwise agreed by the Engineer, all paints forming part of any one painting

    system shall be obtained from the same source. Paint shall be supplied in

    sealed containers of a capacity, unless otherwise approved, of not more than

    one gallon, and shall be used in strict rotation. Samples of paint from each

    making batch shall be submitted to a laboratory for tests as may be required

    by the Engineer.

  • MTECH CONSULTANTS

    S2/12

    12.8 Paint Removers

    Water rinseable and solvent rinseable paint removers shall comply with the

    requirements of BS 3761.

    Certificates that the material has complied with the foregoing tests shall be

    supplied by the manufacturers.

    13) TESTING

    13.1 Testing of Steel Structures

    All tests on structural steel shall be carried out in accordance with Singapore

    Standard CP8:1978 "Use of Manual Metal-Arc Welding in Steel Building

    Construction" and BS 4360.

    13.2 Non-destructive Testing

    The Contractor shall afford all facilities for the inspection of the work at all

    stages by the Engineer or his inspecting Engineers at the Contractor's works

    and those of his subcontractors. All works shall be subject to inspection

    before shipment to the site. Any work found defective or which is not in

    accordance with the drawings or specifications shall be rejected and shall at

    once be made good or replaced where deemed necessary by the Engineer.

    The Contractor shall give such reasonable notice to the Engineer or his

    inspecting Engineer of the progress of the work as will enable the inspection,

    examination and testing as required.

    Samples of materials and workmanship to be employed in the works may be

    called for at any time by the Engineer. Cost of providing and obtaining all

    samples shall be deemed to be included in the rates entered in the Breakdown

    Cost of Works.

    The Contractor shall arrange for all materials to be tested at the

    manufacturer's works and when required in the presence of the Engineer's

    inspector. When materials are obtained from supplier's stock, the Contractor

    shall, by means of identification marks stamped on the materials together

    with the manufacturer's test certificate, show that such materials comply with

    the requirements specified herein.

    The Engineer reserves the right to require an independent analysis and tests

    on the materials by an approved PSB accredited laboratory selected by him.

    For this purpose the Engineer's inspector will take drilling for analysis and

    have pieces cut out side by side with pieces subjected to test in the

    workshops, in order that a comparison can be made. Should the result of any

    independent analysis or test be unsatisfactory, the material represented will

    be rejected.

  • MTECH CONSULTANTS

    S2/13

    The cost of all tests made by manufacturers or made at the works of the

    Contractor or his subcontractors or at the site shall be deemed to be included

    in the rates entered in the Breakdown Cost of Works. The cost of

    independent testing ordered by the Engineer shall be charged against the

    provisional sum in the Breakdown Cost of Works, except for tests on

    materials which are rejected, which shall be borne by the Contractor.

    2 METALWORK

    2.1 Galvanised Steel

    a) All sections to be made from steel plates shall be in accordance with BS

    4360, rods and bars are to be in accordance with BS 1449 Part 1 and 2 of low

    carbon galvanised steel. Small steel angles, tees and channels shall be of cold

    rolled section complying with BS 2994.

    b) Unless otherwise stated, all steel sections, channels, angles, brackets, plates,

    chains, trusses, pipes, frames, etc. including fasteners shall be hot-dip

    galvanised. Any damaged/cut/welded parts shall be treated with two coats of

    appropriate primers and zinc based compatible paint or equivalent

    respectively.

    c) All galvanised steel bolts used shall include heads, nuts and washers.

    2.2 Stainless Steel balustrades and handrails

    Supply and install stainless steel pipe balustrades and handrails consisting of

    balusters, handrails, horizontal intermediate and bottom rails, the whole welded

    together and including fixing to brick or concrete wall and concrete kerb with

    stainless steel plates, brackets, etc.

    2.3 Galvanised, Steel Channels, Angles, Brackets, Plates, Etc.

    Supply and fix all galvanised steel hollow sections, channels, angles, brackets

    purlins, flashings, plates, etc.

    2.4 Galvanised Steel Framings

    Supply and fix galvanised steel framings consisting of hollow sections, channels,

    angles, brackets, plates, etc. with welded or bolted connections.

  • MTECH CONSULTANTS

    S2/14

    2.5 Galvanised Steel Grilles

    Supply and fix galvanised steel grilles painted with two coats of zinc chromate

    primer, one undercoat and spray painted with two finishing coats of enamel paint.

    2.6 Galvanised Steel Mesh

    Supply and fix polyester powder coated expanded galvanised steel mesh complete

    with galvanised steel frame.

    2.7 Galvanised Steel CurtainTruss

    Construct galvanised steel stage curtain truss consisting of hollow sections, channels,

    galvanised steel plates, etc. welded together including painting with two coats of

    primer before delivery to site.

    2.08 Aluminium Work Generally

    a) All aluminium works stated hereof shall be fluorocarbon finish to Engineer's

    approval unless otherwise stated.

    b) All aluminium members shall be factory fabricated to the best standard of

    workmanship and under experienced factory supervision and control. Shop

    drawings shall be submitted to the Engineer for approval prior to

    prefabrications.

    c) All joints in frames at corners, junctions or intersections, shall be electrically

    welded, or mechanically cleated or made with the best trade type of joints

    with all due care.

    d) All aluminium sections shall be so designed to suit the required height and

    span and comply with statutory requirements on lateral loadings where

    applicable.

    e) Samples of flurocarbon coated aluminium sections shall be submitted to the

    S.O. for approval prior to commencement of work.

    2.09 Aluminium Windows, Louvred Windows, Doors, Etc.

    a) Supply and fix approved aluminium top hung, sliding windows, etc complete

    with frames, mullions, transoms, ironmongery, weather strippings, glazing

    beads and other matching accessories.

  • MTECH CONSULTANTS

    S2/15

    b) Supply and fix approved aluminium adjustable louvred window frame and

    fittings with poly-propylene clips to receive 6mm thick x 150mm wide glass

    louvres and 150mm wide aluminium blades, screwed to aluminium frames

    including control mechanism, flush handle and coupling mullion etc.

    Separate control mechanism for aluminium blades and glass louvres.

    c) Supply and fix approved aluminium fixed louvres in accordance with

    manufacturer's details.

    e) Supply and fix aluminium louvred door.

    f) Supply and fix aluminium flush doors infilled with foamed polyurethane.

    g) All windows, sashes and other opening units shall have weather stripping of

    rubber gaskets, neoprene setting blocks and approved silicon water-resistant

    sealer, and doors shall have weather stripping of certified high pile wool

    mohair with silicon water-resistant treatment to eliminate water leakage in

    extreme weather conditions. All joints between aluminium head or cill and

    concrete surfaces shall be also similarly treated with silicon water-resistant

    sealer.

    h) All units shall be prepared for glazing with aluminium glazing beads, non-

    setting putty and/or press-fit rubber gasket or other equal and approved

    proprietary method.

    i) All aluminium sections for double leaf doors shall be of single piece rebated

    sections.

    2.10 Aluminium Catladder

    Supply and fix natural anodised aluminium cat ladders.

    2.11 Roller Shutters

    Supply and fix manually operated roller shutters constructed of zinc and aluminium

    coated and colorbond steel curtain material permanently lock-seamed to form a

    continuous curtain with the edges treated with self-lubricating seamless braided

    nylon polyglide to prevent metal to metal contact. The drum assembly shall consist of

    suitably graded oil-tempered torsion springs secured to drumwheels moulded from

    engineering plastics. The curtain top shall be fully secured and wrapped around the

    drum assembly to form a cylindrical tongue tube which is to be bored up. The bottom

    rail shall be an extruded aluminium section lock-seamed onto the bottom of the

    curtain with the base of the rail containing two slots to retain seamless finned pvc

    weatherhood. Locks shall be dual mode waist-high lock with finger-grip recesses. All

    in accordance with the manufacturer's details.

  • MTECH CONSULTANTS

    S2/16

    2.11 Roller Shutter (Contd)

    Safety Stop : When the resistance is felt while closing the roller shutter, then the

    motor stops.

    Quality : Prime quality.

    2.12 CANCELLED

  • MTECH CONSULTANTS

    S3/1

    SECTION 3 DRAINAGE WORKS

    1.0 General

    The whole of the works shall be executed in accordance with the current

    Standard Specification for Drainage Works, Code of Practice for Surface Water

    Drainage, Drainage Regulations of the Drainage Department of the Environment

    Ministry (ENV), Drainage System Regulations and latest Code of Practice on Sanitary

    Plumbing and Drainage System of the Environment Ministry, Singapore.

    1.1 Materials

    The materials shall generally follow that stated under Notes in the drawings. The

    concrete and steel reinforcement generally shall be as described in Section 10 -

    Reinforced Concrete. The brick masonry shall be as laid out in Section 13 - Masonry.

    Vitrified clay pipes and fittings shall follow the requirements of BS 65 and BS 540 and

    shall be provided with approved flexible joints to BS 2494.

    Corrugated steel multi-plate pipe shall be in accordance with AS 2041 and AS 2042.

    Precast concrete culverts ( open or boxed ) and slabs shall be tested to SS 183, 214, BS

    7263 and to the requirements of Section 10 - Reinforced Concrete.

    Rubber ring or polyester type fittings shall also comply with the provisions of SS 270.

    The formed polyester shall be securely bonded to the vitrified clay. Pipes having loose

    or damaged rings of socket packings shall not be used.

    Unless otherwise specified, such as limestone aggregate or PVC lining, use approved

    flexible jointed thickwall concrete pipes and vitrified clay pipes with flexible joints in

    accordance with current specifications, SS 183 where applicable, and testing

    requirements of the Drainage Department of the Environment Ministry (ENV).

    1.2 Pipes

    1.2.1 Reinforced Concrete Pipes

    Concrete pipes, bends, channels for drains, manholes and culverts shall be obtained

    from an approved manufacturer and shall be made from Portland Cement and the pipes

    ( preferably spun reinforced concrete pipes ).

    If permitted by the Engineer, the pipe may have collar joints when socketted pipes are

    unavailable. Socketted pipes shall have the sockets cast with the barrel of the pipe.

    All drains using reinforced concrete pipes and are of nominal internal diameter between

    300mm and 825mm shall comply with the requirements of Sewerage Department ,

    ENV.

    The joints shall be of a type that remain completely watertight while accommodating a

    rotation of 5 in any direction taken from the axes of either connecting pipe at the joint.

    1.2.2 Pitch - Fibre Pipes

    Pitch fibre pipes and fittings shall be of an approved type and manufacture conforming

    in all aspects with BS 2760. They shall comply with the requirements of the Drainage

  • MTECH CONSULTANTS

    S3/2

    Department, ENV. The joints shall be of a design to permit flexibility and movement

    without leakage.

    1.2.3 Cast - Iron Pipes

    Cast-iron pipes and specials and cast iron ( spun ) pipes shall comply with the

    requirements of BS 4622 ,BS 1211, BS 2035 wherever applicable and shall be Class 1.

    The term cast-iron also embraces spun-iron where applicable.

    Unless otherwise indicated, joints to cast iron pipes shall be screwed gland, bolted

    gland or a proprietary rubber ring joint Tyton or other approved.

    Gaskets for flanged pipes shall comply with BS 2494 and BS 3063 and shall be full

    face, Class D of nominal thickness 3mm. Bolts, nuts and washers shall be in

    accordance with BS 4190 and BS 4320. Where flanged bolts are to be installed and

    buried underground, the bolts, nuts and washers shall be non-ferrous or metal coated to

    prevent corrosion.

    1.2.4 UPVC pipes

    Unplasticised polyvinyl chloride ( UPVC ) pipes and fittings shall be of an approved

    type and manufacture complying with the requirements of the Drainage Department,

    ENV. They shall conform to SS 272, BS 4660, BS 5481 and the relevant Australian

    Standards where applicable.

    1.2.5 Corrugated Steel Multi - Plate Pipe

    Yield Stress : 230 MPa

    Elongation : 16 % on a gauge length of 200mm

    The tests shall be carried out in accordance with AS 1391

    Unless another type of coating is specified, sheets which are HDG after fabrication

    shall have an average coating of not less than 600 g/m2

    ( total both sides ) as

    determined by the spot test method described in AS 1650.

    The pitch of the corrugations in the sheets shall be 13 1.5 mm. The corrugations shall

    form smooth continuous curves and tangents. The inside radius of each corrugation

    shall not be less than one-half of the depth of the corrugation.

    1.3 Earth Drains

    1.3.1 Table drains

    Table drains shall be provided at the outer edges of the berms in cuttings as shown on

    the drawings and other locations as directed by the Engineer. Table drains shall be

    evenly graded throughout their length without stepping and shall be flared outwards

    from the formation. Table drains shall be diverted at the intervals as shown on the

    drawings so as to discharge water into the open drains, water courses, culverts or upon

    natural ground such that a natural gravity induced flow pattern results in proper

    drainage flow in the required direction.

  • MTECH CONSULTANTS

    S3/3

    1.3.2 Catch drains and other open drains

    Where the natural surface drains towards cuttings, catch drains shall be provided,

    before or during the excavation of the adjacent roadway, above each cutting as shown

    on the drawings or directed by the Engineer. The edge of the catch drains shall not be

    less than 2.5 m cuttings nor more than is necessary to maintain the fall of the drains.

    Catch basins shall generally by at least 300mm deep and side slopes not steeper than

    the batter applicable to the material through which they are cut. The gradient shall be

    designed to ensure free flow of water and shall not be less than 1: 100 unless otherwise

    directed by the Engineer.

    Catch drains shall be cut in uniform lines. Where obstructions occur in the line of a

    catch drain, the drain shall be diverted in a manner satisfactory with the required

    performance and as directed by the Engineer. Where hard rock occurs along the line of

    the proposed catch drain, the Engineer may propose the use of graded banks to

    intercept the water or that the catch drain be dispensed with and that the provision be

    made for interception of the drainage further away from the cutting or for widening or

    deepening the table drain into which the water will flow.

    Where graded banks are required in-lieu of catch drains, the Contractor shall construct

    in the same location an embankment not less than 450mm high by 300mm wide at the

    top, with both side slopes not steeper than 2 horizontally to 1 vertically ( 2: 1 ).

    Material for the embankment shall be obtained either from the excavation work or by

    neatly or uniformly trimming back the top edge of the batter of the adjacent cutting.

    At side roads and vehicle entrances, catch drains shall be diverted to the table drains or

    other drainage system available as directed by the Engineer. Where shown on the

    drawings or as directed by the Engineer, longitudinal median drains shall be provided

    between divided carriageways. Other open drains shall be provided at outlets from

    catch drains, table drains, subsoil drains, kerb and gutter and all other points of water

    concentration to lead the water in approved paths to underground drainage systems. As

    far as practicable, the water shall seek its own level by following existing watercourses

    and depressions in the natural ground or by following underground flow patterns

    through pervious layers in the soil and rock.

    1.3.3 Lining of earth drains

    Where shown on the drawings or as directed by the Engineer, earth drains which have

    a gradient of at least 5% shall be stone-pitched or concrete lined. Pitching shall consist

    of sound durable rock not less than 150mm thickness or precast concrete blocks not

    less than 100mm thickness, properly bedded on approved loam or sand to present a

    uniform surface. The exposed surface of each stone or block shall be flat and not less

    than 0.03 m2

    . Joints between adjacent stones or blocks shall not be larger than 12mm.

    1.4 Precast concrete drains and box culverts

    The precast concrete sections shall be true to shape as given in the Drainage

    Departments size catalogue. All units delivered to site shall be inspected and free from

    defects before being allowed to be used in any part of the works. Precast channels,

    revetment slabs, etc. shall be properly laid to fall, bedded on a sand base at least 75mm

    thick unless otherwise stated and joints poured with cement mortar. Precast box

    culverts and drains requiring built-up sections as additional wall and roof slab sections

    shall be made to the provisions of the drawings and Section 10 - Reinforced Concrete.

  • MTECH CONSULTANTS

    S3/4

    1.5 Subsoil Drains

    1.5.1 General

    Trenched for subsoil drains for pipes up to 150 mm in diameter shall be excavated to a

    width of at least four times the nominal diameter of the pipe or as shown on the

    drawings. For a pipe diameter above 150mm, the width shall be the external diameter

    of the pipe plus 450 mm or as shown on the drawings. Unless otherwise stated, drains

    shall consist of 19mm aggregate with a perforated 100mm PVC pipe at the bottom. The

    whole of the drain shall be wrapped in a layer of geofabric complying with Class B as

    shown in Table 21.1 in page S21/4. The subsoil shall be bedded on a 50mm thick lean

    concrete base with a maximum aggregate size of 10mm.

    1.5.2 Geotextiles

    Table 21.1 Physical Properties of Geotextiles

    Class of Geotextile

    Physical property

    Class A Class B

    Specification

    Minimum Unit Weight,

    g/m2

    125

    50

    ASTM D3776

    Minimum Grad Tensile

    Strength, N

    530

    270

    ASTM D1682

    Minimum Elongation to

    Break, %

    60

    55

    ASTM D1682

    Minimum Trapezoidal

    Tear Strength, N

    180

    80

    ASTM D1117

    Minimum Mullen Burst

    Strength, N/mm2

    1.10

    0.50

    ASTM D774

    Water Permeability,

    cm/sec

    2.0 x 10-2

    2.7 x 10-2

    Manufacturer's test

    report to be

    submitted

    Generally non-woven type geotextile may be used and shall be from the following

    materials :

    ( a ) polypropylene

    ( b ) polyethylene

    ( c ) ployamide

    Ensure that all geotextiles are protected against direct sunlight and contamination of

    chemical solutions while in storage. Only minimum exposure to weather during laying

    is permitted. Geotextiles with stain markings shall be rejected. The following tests shall

    be carried out when required by the Engineer :

  • MTECH CONSULTANTS

    S3/5

    ( a ) Load vs Strain to ASTM D 1682

    ( b ) Grab Tensile Test to ASTM D 1682

    ( c ) Trapezoidal Tear Test to ASTM D2263-68

    ( d ) Mullen Burst Test to ASTM D751 -73

    ( e ) Water Permeability Test

    ( f ) Pore - Size Distribution Curve

    1.6 Scupper drains

    These shall be laid from the roadside drains to the concrete kerbs. Revetments and

    channels to the roadside drain shall be broken into to place and connect the scuppers

    and the connections made good with cement mortar mix. Each pipe shall be properly

    bedded down and all but joints sealed all around with cement mortar filleted up to form

    a collar 50mm wide by 25mm thick.

    1.7 Excavation

    1.7.1 General

    Excavation shall be carried out to the requirements of Section 3 - Excavation and to the

    relevant requirements of the Drainage Department, ENV. The Contractor shall provide

    the necessary scope of excavation works to the Engineer prior to commencement for

    approval. The Contractor shall also obtain all permits and carry out trial trenches and

    location of services as required.

    1.7.2 Excavation proper

    The Contractor shall notify the Engineer sufficiently in advance of the beginning of

    any excavation. The natural ground adjacent to the structure shall not be disturbed

    without permission of the Engineer.

    The excavation of the trenches shall be to lines and gradients required for the pipes,

    channels, etc. The trench bottom shall be of sufficient width to allow adequate working

    space for the pipe joiners. Unless otherwise specified, excavated material shall not be

    deposited within 500mm of the edges of the trench.

    The sides of the excavation shall be supported by planking and strutting if necessary

    to ensure the proper execution of the work. Trenches shall be provided with planking

    and strutting for depth of excavation not less than 1.5m.

    The method and materials for planking and strutting are to be certified by the

    Contractors P.E. and approved by the Engineer. In the event of excavation being

    made deeper than necessary, they shall be made up in Grade 15 concrete at the

    Contractors expense. The excavation shall be kept free from water by pumping,

    baling or otherwise.

    Brace all excavation adequately and securely with suitable timber using the methods

    indicated in the drawings and otherwise certified by the Contractors P.E. and approved

    by the Engineer. Notwithstanding the approval given, the Contractor is to improve ,

    alter , strengthen and inspect the shoring from time to time.

    The Contractor shall be responsible for any damage to the works therefrom. Any

    permission by the Engineer to carry out a certain form of works based on the

  • MTECH CONSULTANTS

    S3/6

    Contractors methodology does not relieve the Contractor from carrying out the said

    works to a safe and required standard of construction as required by that methodology.

    The foundation pits for structures shall be excavated to the lines and levels

    shown on the plans or as indicated by the Engineer. They shall be of sufficient

    size to permit the placing of structures at the full width and length shown. Boulders,

    logs and any other objectionable material encountered in excavation shall be removed.

    After the excavation is completed, the Contractor shall notify the Engineer to that

    effect. No bedding or pipe shall be placed until the Engineer has approved the

    excavation and the character of the foundation materials.

    In the particular case of materials left in the excavation, this shall be approved by the

    Engineer and such materials shall be removed to the best of the ability of the contractor

    before closure of the excavation

    The Contractor shall take any action required by the Engineer when, in the opinion of

    the Engineer, the excavation or related works are deemed to be of a standard which

    would cause concern for the safety of personnel or for the execution to achieve a

    required standard of the works.

    1.7.3 Bakau piling

    Provide piling to the drawings and the requirements of Section 20 - Timber Piling and

    especially to Clause 20.13 and related sections where required.

    1.7.4 Pipe-laying works

    (a) General

    Except for sub-clauses below, the pipe shall be placed on a firm earth foundation of

    uniform bearing capacity for the entire length of the structure and to the line, levels and

    camber established by the Engineer. Where rock or other unyielding materials is

    encountered it shall be removed to at least 300mm below the bottom of the structure.

    The width of the excavation shall have a minimum of 600mm greater than the pipe

    diameter. The excavated area shall be backfilled with selected material and be

    thoroughly compacted to provide a cushion for the structure.

    When soft, spongy or other unstable soil is encountered at the level established, it shall

    be totally removed and replaced with well compacted granular material to provide a

    uniform and adequate support for the pipe. Under these conditions the width of the

    trench shall be at least three times the pipe diameter and as deep as the foundation

    condition requires and as directed by the Engineer. Unless otherwise specified, the

    foundation shall have a thickness of 300mm.

    (b) Pipe laying

    Carefully brush all pipes inside and visually test for soundness before laying the pipes

    on the compacted foundation material or concrete. Lay the pipes to true inverts, straight

    lines and falls, each pipe being separately bonded between sight rails and bearing

    evenly on the supports for the full length of the pipe.

    Where pipes are to be laid on rock cutting, take the excavation down 100mm below the

    bed level and ensure that no projecting pieces of rock are present which may ride the

    pipe. Make up the bed to its true line and level by refilling with either 100mm of

  • MTECH CONSULTANTS

    S3/7

    consolidated, selected material from the excavation, well rammed and watered as

    necessary or with 100mm of compacted sand or with G15 benching concrete as

    required.

    Where pipes are to be supported on a bed of concrete surrounded with concrete,

    provide rectangular blocks composed of concrete made in approved moulds at least 14

    days before use and approved hardwood folding wedges. Provide two blocks for each

    pipe set and bond into the correct level on the formation bottom and lay the pipe on

    them properly centred and socketted.

    1.7.4 Pipe-laying works

    (b) Pipe laying

    Two hardwood folding wedges of a width equal to that of the concrete block shall then

    be inserted between the body of the pipe and the block and shall be driven together

    until the pipe is brought to the exact level required. Blocks and levels shall be left

    undisturbed while the pipes are being joined and the concrete surround is being placed

    in position. Ensure that the procedure does not cause settlement or compensate for the

    settlement so caused. For lengths of pipe, deflected on plan, the curve shall be obtained

    by the deflection of each pipe at each joint position.

    1.7.5 Jointing

    (a ) Cast - iron pipe

    In general for all types of joint, thoroughly clean the pipe joint and the jointing ring or

    material of dirt and grease before any jointing commences. The pipes shall be properly

    supported, bedded and lined-up before the joint is set and made. Refer to Section 21.3.4

    for laying operations. Make bolted glands, screwed glands, and similar types of flexible

    patented joints in accordance with the manufacturers instructions. Clean the joint

    rings, lubricate with the manufacturers recommended material and accurately position

    it. Firmly push or jack home the joint and where screwed or bolted glands are involved

    steadily and evenly tighten the glands all around.

    No lead caulked joints shall be permitted. Carefully clean the flanged joints, center and

    line up with only 3mm allowed for the gasket between the faces of the flange. The

    flanged gasket shall be carefully positioned and held by the flanged bolts.

    (b) Vitrified clay pipes

    In the case of vitrified clay pipes with flexible joints, similarly brush clean the spigot

    and the socket of each pipe before the rubber ring is placed in the groove. Apply an

    approved soft soap lubricant to the rubber ring and the inside face of the socket. Insert

    the spigot into the socket and push straight home.

    Where vitrified clay flexible joints are used, the manufacturers specifications shall be

    deemed to form part of this Specification. Ensure that no damage to the joints are

    caused during handling, stacking and laying. Such damaged goods are deemed

    unacceptable for use and shall be removed from the site immediately.

    (c) Concrete pipes

    Push well home the concrete pipe with the rubber ring aligned on the spigot into the

    socket of the previously laid pipe by means of uniform pressure with the aid of a jack

  • MTECH CONSULTANTS

    S3/8

    or similar appliance. Use a roll on rubber ring and well lubricated before making the

    joint by the use of soft soap, water or other approved lubricant supplied by the

    manufacturer. The manufacturers instructions on the system shall be deemed to form

    part of this Specification.

    Lay the PVC lined concrete pipes and join as specified above except that all necessary

    precautions shall be taken to protect and safeguard the PVC lining from any damage

    during pipe laying. After the pipes have been approved as laid by the Engineer,

    Thermo weld the cover flaps of the PVC across the pipe joints according to the

    manufacturers instruction and this shall be carried out in conjunction with the pipe

    laying progress.

    1.7.5 Jointing

    (c) Concrete pipes

    Where the lined pipes enter the manholes and other structures, seal the PVC lining by

    welding of approved preformed cover fillets or angles forming returns to the arises built

    into the in-situ concrete work.

    The manufacturers drawings and instructions for jointing and the Thermo Weld

    procedure are to form part of the Specifications. The manufacturer shall submit to the

    Engineer the methods for field testing of the PVC lining and Thermo weld joints for

    flaws, burnt surfaces, pin holes etc. Employ approved methods for the complete testing

    of the lining, jointing, and welding throughout the line.

    (d) Corrugated steel pipe

    Damage to the items delivered to the site by improper handling, stacking and placement

    is required. Dragging pipes over rock or gravel may damage the external coatings and

    is to be avoided. All spots damaged shall be repaired with two coats of hot bituminous

    coating or otherwise and repaired in a manner approved by the Engineer. The

    corrugated sections shall be assembled progressively in accordance with the

    manufacturers instructions. Base plates shall be checked for line and levels after

    assembly and after laying the pipe. All bolts and nuts shall be tightened either by air

    compression or engine /electrical driven machine having a controlled torque of up to

    0.405 kNm.

    A hand torque wrench shall be used for random testing on the tightness of the bolts.

    Bolts shall not be overtightened. Standard bolts shall be furnished in two lengths - short

    where the plates lap and long for drawing the plates are drawn together and then

    replaced by the short variety.

    1.7.6 Fracture of pipes

    In the event of the pipes being fractured after being, to all appearances, properly laid,

    whether due to imperfect beds having been formed or the materials for refilling having

    been improperly selected or due to any other cause, the Contractor shall be responsible

    and shall be called upon to replace such defective pipes if such pipes have been

    identified before the end of the Defects Liability Period. Immediately remove any

    length of pipe so affected and remake all leaking joints.

  • MTECH CONSULTANTS

    S3/9

    1.7.7 Clearing pipes of obstruction

    After testing the pipelines as specified and at a time to be directed by the Engineer,

    inspect the interior of the pipelines to ascertain that the liens are entirely clear of

    obstruction and that the invert is smooth. The outside diameter of the ends of the

    plugshell not be smaller than the diameter of the pipe through which it is to be passed

    by and its length shall not be less than its diameter.

    The Engineer may not instruct the Contractor to carry out this test until he is satisfied

    that the lengths concerned are complete and ready for operation. After testing, remove

    all obstructions and remake any unevenness to the invert to the required standards. If,

    as a result of such removal, the Engineer considers any damage may have been caused

    to the pipelines, the Contractor shall be required to re-test and make good those lengths

    affected. Should such testing show any deficiency in the works, remedy the defects as

    required on the instruction of the Engineer.

    1.8 Testing gravity pipelines

    Test all gravity pipelines and drains of 525mm or less in diameter before being

    surrounded and covered by filling with water in a manner approved by the Engineer.

    The pressure shall be measured from the highest point of the pipeline under test and

    shall be a 1.2m head of water. Pipelines shall not be accepted until they have withstood

    the required pressure for 30 minutes without loss in excess of 1.5 litres for a length of

    100mm for each 300mm diameter of pipe.

    Where the maximum head at the lower end exceeds 2.5m, the sewer shall be tested in

    sections at the discretion of the Engineer and the Contractor shall make all necessary

    arrangements for the testing. Gravity sewers larger than 525mm diameter shall not be

    hydraulically tested but the joints shall be inspected and shall be made good to the

    satisfaction of the Engineer.

    The pipes shall not be covered until they have been tested and/or inspected , and

    passed.

    After each section of pipe has been tested and passed, bed haunch and surround the

    pipes with G30 concrete as required in the drawings. At approximately every 6m or

    four pipes , whichever is lesser, form a joint in the concrete bed or surround by

    vertically shuttering the bed or surround with a 25mm thick fibreboard, timber or other

    approved material. Leave the shuttering material in to form a permanent joint. Where

    the concrete bed is required to be reinforced, stop all reinforcement on either side of the

    joint. The whole of the joint shall be thoroughly set before any refilling works

    commence.

    1.9 Tumbling bays and backdrops

    Use special spigot and socket junctions in the junction between two lines of pipes. For

    backdrops and tumbling bays more than 300mm in diameter, the junction shall be cast

    iron to approved dimensions and shape. Lay the tumbling bays or backdrop pipes on a

    concrete foundation and completely encase in 150mm G30 concrete surround as shown

    in the drawings.

  • MTECH CONSULTANTS

    S3/10

    1.10 Inspection Chambers

    1.10.1 Masonry I.C.

    Construct all masonry i.c. to the requirements of Section - Masonry. Render the base of

    the chamber with cement render 20mm thick. Flush point internal and external joints of

    brick chambers in 1:3 cement mortar and finish to a smooth surface.

    1.10.2 Precast I.C.

    Set the individual pieces of the chamber walls on a preformed r.c. foundation

    comprising a G30 base and a built up cast-in-situ r.c. section ( if required ) and as

    shown on the drawings. Construct the base, benching and pointing of all precast and in-

    situ concrete chambers in OPC unless otherwise directed. Form the benching at the

    soffit level of the outgoing sewer pipe rising by 75mm to the manhole walls. Form

    curves and junction benchings to a radius in the centre line of the channel not less than

    one-and -a- half times the diameter of this pipe.

    Set the r.c. slabs covering the chambers and shafts of the i.c. in 1:3 cement mortar to

    form a watertight joint. Form channels and benching to the concrete floors of the

    concrete i.c. in OPC concrete and to the required levels and falls. Set i.c. covers and

    frames as specified herein in cement mortar and surround with G30 concrete and covers

    to be left flush with the level of the finished road surface, ground or otherwise agreed

    datum with the Engineer.

  • MTECH CONSULTANTS

    S3/11

    1.11 Backfilling of drain trenches and excavation

    Earthfilling from the bottom of trenches and to a height of 300mm

    above the top of the pipes shall be of selected materials, compacted, watered if

    necessary and well rammed on either side of the pipes.

    The remainder of the earthfilling shall be in layers of 300mm each, watered if

    necessary and well rammed with mechanical rammers or other efficient means of

    effecting compaction.

    The pipes shall be carefully handled during this operation. In the opinion of the

    Engineer, if such work causes damage to the pipes then the Contractor shall rectify the

    damage to the satisfaction of the Engineer before proceeding with the remainder of the

    works.

    1.12 Pipe jacking

    1.12.1 General

    Where specified, sections of the sewer shall be laid by pipe jacking. Alternatively, the

    Contractor may propose the pipe jacking method provided that the overall scope of

    works are not, in the opinion of the Engineer, affected by such a method.

    Submit details of the construction equipment, materials and the method of laying and

    construction to perform and complete the work for approval by the Engineer before

    commencing these operations.

    Approval by the Engineer shall not relieve the Contractor of the sole responsibility in

    ensuring the safety, efficiency, reliability or completeness of the method employed to

    carry out this particular form of construction.

    The general soil profile along the route of the sewer at depth shall be given in the

    borelogs for the information of the contractor only. The interpretation, design,

    execution and delivery of the final product shall rest solely on the Contractor. The

    Employer accepts no responsibility for the accuracy, reliability or completeness of this

    information. The Contractor is to ensure the soil conditions along the route at his own

    expense.

    Maintain stable soil conditions at the jacking face to prevent loss of ground above the

    jacking operation and the subsequent movement of the surrounding soil. The methods

    of maintaining face stability and preventing ground movement and subsidence shall be

    by means of compressed air or other plenum methods where fluid slurry or earth

    pressure is applied to the tunnel face.

    Alternatively, stabilise unstable ground ahead of the jacking face by the injection of

    suitable chemicals methods which require dewatering of the soil and methods which

    may lead to significant loss of subsurface material shall not be accepted. Soil

    stabilisation methods shall be submitted to the Engineer for approval.

    Movement and other settlement monitoring shall be provided of structures, utilities and

    pavement by the Contractor to the Engineer and which are continuously assessing the

    ground conditions between the surface and the jacking levels during the course of the

    works.

  • MTECH CONSULTANTS

    S3/12

    If movement or settlement occurs which, in the opinion of the Engineer, may cause

    damage to existing structures or the works, then immediate action shall be tank to

    prevent further movement and rectify the damage taken place to the satisfaction of the

    Engineer.

    1.12.2 Materials

    The pipes for the jacking operation shall be precast reinforced concrete pipes. The

    pipes shall be manufactured by a centrifugal or other equivalent process to be approved

    by the Engineer. Design, manufacture and factory testing of the pipes and specials

    shall be to SS183, BS 5911 or AS 1342 or other acceptable standards. All pipes shall be

    manufactured with two sets of grout holes. Each set shall consist of three grout holes

    spaced at 120 on centres circumferentially located at quarter points from either end of

    the pipe section.

    The precast reinforced concrete pipes shall be sufficiently reinforced with steel

    reinforcement to withstand all stresses induced by handling, jacking , earth and water

    pressures at the depths they are to be placed during service without cracking, spalling

    or distortion to the limits of the relevant codes for water retaining structures especially

    the required limits in BS 8007.

    The pipes shall be at least of Class H designation. A load factor of not larger than 1.5

    shall be used in the calculations to determine the strength of the pipes required. The

    strength of the pipes shall be tested by the three edge bearing test. When subjected to

    the design load in such a test, the maximum crack width developed on the pipe shall not

    exceed 0.25 mm.

    The full details of the proposal including detailed drawings showing pipe sizes,

    reinforcement details, types of joint, calculations on pressure on pipes etc. together

    with the name of the nominated manufacturer, place of manufacture, process used and

    any other pertinent data shall be submitted to the Engineer for approval.

    The joints supplied shall be of the Cornelius rubber ring type or similar approved. Joint

    rings shall comply with BS 2494 Part 2 for Grades between B and D.

    All workmanship and materials shall be subject to the approval of the Engineer who

    will from time to time inspect the materials at the source and the plant of manufacture

    during the manufacturing process.

    The pipes shall be sufficiently mature before they are used in the works. Repaired pipes

    shall not be used in the Contract. The Engineer shall reject any material including pipes

    if they do not meet the criteria submitted by the Contractor or, in the Engineers

    opinion, the relevant sections of the codes.

    Every pipe shall be marked after inspection and catalogued according to the date of

    manufacture, date approved for works, number of the pipe to leave the factory and the

    testing authority. test certificates from the manufacturers or other relevant authority

    shall be submitted to the Engineer.

    Where steel collars are used for pipe joints, they shall be made from Grade 43 steel to

    BS 4360. The collars shall be of the dimension and thickness to be approved by the

    Engineer. Before being fitted to the pipes, the collars shall be coated with an approved

    anti-abrasive and anti-corrosive material such as polymorphic resin or equivalent.

  • MTECH CONSULTANTS

    S3/13

    Where a steel shield is used for jacking operations, bolt by approved methods the first

    pipe to the shield. A jacking ring can be of either r.c. or structural steel and shall be

    used at all times when a pipe is being jacked. The jacking ring shall allow the even

    distribution of the jacking pressure around the wall of the pipe.

    The jacking frame shall be used during all operations and designed to distribute the

    stresses evenly from the jacks to the jacking ring in an even manner.

    1.12.3 Jacking operations

    The Contractor shall be fully responsible for the materials , construction equipment and

    facilities required in conjunction jacking the reinforced concrete pipes.

    Before starting work, submit to the Engineer for approval a detailed schedule of the

    entire jacking operation. Approval of such schedules shall not relieve the Contractor of

    his responsibility to provide a fully satisfactory installation. Provide together with the

    submission evidence of successfully completing other projects in a similar manner to

    that proposed. Where the Contractor proposes to use compressed air, his proposal shall

    include the relevant sections in the Specifications for Working in Compressed Air and

    Work in Compressed Air.

    Where chemical stabilisation of the soil is required, pressure injection of a chemical

    grout into the soil over and in front of the jack shall be used to stabilise the soil. The

    chemical grout used shall have a demonstrated history of success for stabilising soils

    similar through that which the pipe is being jacked. Where a mechanical shield is being

    used, provide past cases of jacking capability in soils of the type currently encountered.

    Jack the pipes in place true to line and level. The maximum tolerance allowable in the

    displacement of the centreline of the laid pipe from the designed centreline is 50mm in

    the horizontal plane and 25mm in the vertical plane but there should be no backfall at

    any point. Any pipe not meeting the requirements for tolerance shall be removed or

    repositioned to achieve the tolerances.

    There shall be provision to prevent the relative movement between pipes at joints by

    use of steel gaiters or other approved methods during the jacking operations.

    Furnish, install and remove thrust blocks or provisions involved in driving the pipes

    forward. Provide means to initially align the pipes in the pits by use of beams or rails

    and submit proposals for approval to the Engineer. Monitor closely the progress of the

    jacking operation. Daily site logs of thrusting pressures and line and level

    measurements shall be maintained and submitted immediately after the days work or

    in 24 hour cycles for continuous work.

    Carry out any remedial works to ensure a watertight structure during the works and the

    period of Defects Liability to the requirements of the Contract.

    1.12.4 Cement grouting

    Prevent the occurrence of voids outside the pipe and if they occur, fill immediately with

    cement grout. Immediately following the jacking operation, pressure grout the jacked

    section to fill all the voids outside of the pipe. Grouting shall be from the inside

    through the grouting holes as provided.

    Provide a system of standard pipe, fittings, hose and special grouting outlets embedded

    in the pipe walls. All parts of the system are to be free from dirt. Carefully force grout

  • MTECH CONSULTANTS

    S3/14

    composed of cement, sand and other approved compounds under a steady pressure into

    the grouting connections at the invert and proceed until the grout flows in from the

    upper connections. make connections to these holes and repeat the process until

    completion.

    After grouting, maintain pressure by means of stop cocks or other means until the grout

    has set sufficiently. After grout has set, completely fill the grout holes with concrete

    and finish neatly. For pipes with PVC or HDPE linings carry out grouting and ensure

    that lines are watertight before proceeding with the jointing of the linings of the pipes

    and the patching of the linings over the grout filled holes.

    1.13 Inspection Chamber

    1.13.1 General

    All inspection chambers shall be made monolithic with the pipe sections placed by

    trenching or pipe jacking. The inspection chambers shall be constructed to the drawings

    and the relevant sections of the Specifications, particularly Sections 3, 10, 13 and this

    Section.

    The chambers shall sit such that the grades of the main pipes entering and leaving shall

    not be affected by the depth to invert at any point of the chamber. The benching on the

    concrete base shall be not less than that specified. The pipes shall be inserted a

    minimum of 75mm into the walls of the chamber and made watertight with approved

    cement grout mixture or a thixotropic sulphate-resisting non-shrink binder to the

    approval of the Engineer.

    The chamber proper shall be made watertight in the manner described for water

    retaining structures under Section 10 - Reinforced Concrete and shall have adequate

    access equipment for inspection of the base as and when required.

    1.13.2 Inspection Components

    Handrailing for access shall be provided as shown on the drawings. All mild steel pipes

    used for handrails shall be light steel tubes of 40mm nominal bore to BS 1387 and SS

    17. All mild steel tubes shall comply with BS 15 or SS 104.

    Before erection, wire brush to remove all rust and mill scale. Paint the handrailing with

    one coat of red lead oxide primer or equivalent approved. After erection, paint the

    handrails with one undercoat of approved oil based paint and one similar finishing coat.

    Safety Chains shall comply to the drawings and the requirements of Drainage

    Department, ENV. They shall be made of aluminum alloy HE 30 FT.

    Ladders shall be made of aluminum alloy HE 30 FT and of approved design to BS 1474

    and BS 2037. Each rung shall be either cast-in to the concrete walls or bolted with two

    bolts per connection end.

    All HDG gratings shall be zinc coated and in accordance with SS 117 or BS 729 Part 1.

    The amount of zinc coating shall comply with the following average coating mass:

  • MTECH CONSULTANTS

    S3/15

    Thickness of Steel in G43 Average Coating Minimum Permissible

    grammes/m2

    grammes/m2

    5mm thick and over 610 580

    Under 5mm but not less than 2mm 410 390

    Under 2mm 350 330

    Inspection covers and frames shall comply with SS 30 and BS 479 and be of the

    standard size nominated by ENV or LTA. Test loads shall be obtained from the

    relevant authorities.

    Step irons shall be of malleable cast iron and comply with BS 1247 and used only

    under the direction of the Engineer.

  • S4/1 MTECH CONSULTANTS

    SECTION 4 -EXTERNAL WORKS

    Note:

    All specification items contained in other sections of this Specification shall apply equally to

    External Works.

    1. Site Clearance

    The Contractor shall take over the site from the Piling and Earthworks Contractor and shall

    ensure that weeds, shrubs, undesirable growths and debris are removed off the site at the

    beginning and for the duration of the construction operations.

    2. Earthworks

    Excavation and filling to buildings or over site to make up or reduce levels in forming

    embankments, terraces, roads paving, turfed areas, etc. shall be carried out and graded to levels

    and falls as shown on the site plan or as directed on site.

    Filling to be with selected excavated material free from roots and all vegetable matter, filled in

    and well consolidated in layers not exceeding 150mm thick.

    Carefully form all banks in cutting or filling to constant or varying angles as directed.

    All surplus excavated materials deposited in spoil heaps on site shall be removed to a designated

    area adjacent to the site or disposed of as directed.

    3. Turfing and Tree Planting

    General

    The Contractor shall allow in his overall tender price to cover small quantities and spot items of

    turfing works to be done at various spots on site as required by the Engineer.

    Materials

    The grass to be used in turfing shall be good quality approved cow grass (Axonopus Compressus)

    and shall be of healthy and vigorous stock.

    Turfs shall be cut square, not less than 35mm thick and of size 300 x 300mm with square edges.

    The root formation shall be moist, undamaged and solidly embedded in planting mixture.

    The grass shall be green, not more than 35mm long and free from weeds, Care shall be taken to

    include as much of the root growth as possible.

    Turfs shall be laid within 36 hours after being cut. It shall be stacked on site roots to roots and

    grass to grass and shall be kept moist by being sprayed with water and covered with wet sacking.

    Turfs shall be inspected immediately before laying and all turfs which contain weeds shall have

    the weeds grubbed out complete with roots and destroyed. All turfs which are dry, have long

    grass, or otherwise not conform with this Specification shall be removed from site.

  • S4/2 MTECH CONSULTANTS

    3. Turfing and Tree Planting (Cont'd)

    Materials (Cont'd)

    The Contractor shall produce sample turfs for the Engineer's approval before commencing work

    and all turfs laid shall conform to the approved sample.

    Tree shall be of selected stock and shall be obtained from an approved source and shall be

    minimum 12 months old, healthy and delivered to site in their original planting boxes.

    Turfing

    The Contractor shall supply approved quality top soil and sludge, site thoroughly and spread and

    level to a 50mm thickness to all areas to be turfed. Prior to turfing, spread throw evenly approved

    rock phosphate fertilizer at the rate of 0.3kg per square metre to top soil and raked in.

    Turfs shall be laid with joints closely butted together. After laying, each turf shall be

    consolidated until it is well bedded without excessive beating. Any hollow so produced shall be

    packed up from underneath with planting mixture and the turf again beaten. Laying and beating

    shall continue until a solidly bedded continuous turf area is produced, true to the levels and

    gradients shown on the Drawings. On slopes exceeding 1 in 4 the turfs shall be pegged down

    with two or more split bamboo pegs to each turf.

    A patchwork effect to the finished turfing shall be avoided. Turf which contains an undue

    preponderance of a coarse or fine species of grass may be used at the Engineer's discretion if

    distributed evenly among the general turfing, so as to avoid a sudden change in turf's texture.

    The minimum total thickness of turfs and planting mixture shall be 135mm. This shall be

    measured after the turf has been laid and beaten down. Small trial holes shall be dug for this

    purpose in positions indicated by the Engineer. Turfing which shows less than the 135mm

    specified shall be taken up, the correct depth of soil provided and turf re-laid at no extra cost to

    the Contract.

    As soon as the turves have started to grow, approved type of sulphate of ammonia shall be spread

    at the rate of 34 gms per 3 square metre to all turfed areas, followed immediately by generous

    spray of water.

    Grass cutting shall only be carried out after about two months after planting and thereafter once

    every month.

    When mowing on spot-turfed areas, care shall be exercised to see that the growing roots or shoots

    are not cut or damaged. All cut off grasses shall be distributed and left on the turfed areas. Cut

    off grasses arising from subsequent month mowing shall be lightly plastic raked together and

    removed from site.

    Following each grass cutting, the turfed areas shall be rolled over with a smooth roller not

    exceeding 181 kg (400 lbs) in weight.

    The Contractor shall be required to maintain the turfs continuously until the end of the

    Maintenance Period including watering, tending and weeding until the turfs are growing

    satisfactorily. During this maintenance period, the Contractor shall be required to do regular

    grass cutting as and when instructed by the Engineer.

  • S4/3 MTECH CONSULTANTS

    3. Turfing and Tree Planting (Cont'd)

    Tree Planting

    The Contractor's attention is drawn to the current requirements of planting of trees laid down by

    the Parks and Recreation Department (Ministry of National Development) which are to be

    complied with wherever applicable. The standards of the planting, aeration and maintenance of

    trees may be obtained from the Parks and Recreation Department.

    Tree-planting pit shall be at least 1 x 1 x 1m deep. Backfill shall consist of three parts of good

    excavated soil and one part of sludge fin and packed around the plant.

    The Contractor shall protect the plant by erecting a temporary fence with a minimum height of

    1.5m consisting of barbed wires at 150mm c/c wound around five 90mm diameter bakau or

    bintang poles driven 600mm into the ground.

    The Contractor shall tend and water the trees after planting, including weeding as necessary until

    the trees starts to thrive. Any tree that fails to thrive shall be replaced by the Contractor at his

    own expense.

    All trees planted shall be warranted to thrive for a period of one year from the date of completion

    of contract. Trees that failed to thrive shall be replaced at the Contractor's own expense and shall

    be subjected to a further warranty of one year from date of planting.

    Where directed by the Architect, the Contractor shall not cause any damage or harm to existing

    trees or plants which are to be preserved.

    During the maintenance period, the Contractor shall be required to maintain the trees, plants,

    hedges and all turved areas in optimum growing conditions including:-

    (a) removal of dead turves and weeds twice a month

    (b) cutting of grass, trimming and pruning trees, plants and hedges once a month

    (c) fertilizing, watering and maintaining plants in healthy conditions

    4. Aprons

    Generally aprons around building and connecting covered ways, etc. shall be of in-situ concrete

    laid on a prepared bed of hard-core to thicknesses and dimensions as detailed on the drawings,

    reinforced where required or if directed by the Engineer with a layer of an approved fabric

    reinforcement. The top of concrete apron shall be finished smooth with a wood float to receive

    tiles or paved with cement and sand (1:3) paving of the thickness shown on drawings or as

    directed.

    Expansion joints shall be provided in concrete aprons at suitable intervals or in positions detailed

    on the drawings or as directed by the Architect.

  • S4/4 MTECH CONSULTANTS

    4. Aprons (Contd)

    Apron paving slabs, where required, shall be precast concrete slabs of the thickness shown on

    drawings or as directed, cast in varying sizes to suit width of aprons, finished fair on exposed

    faces, laid to falls on prepared bed of sand with joints grouted and pointed in cement and sand

    mortar (1:3) and exposed edges next to channels in cement and sand (1:3) and trowelled smooth

    with rounded arises.

    5. Road Works

    General

    All road work and its associated facilities shall be constructed in accordance with LTA Standard

    Road Details for Street Works and its requirement, and to the drawings and other specification

    provided herein.

    Subgrade of Driveway

    The finished level of subgrade shall be shaped and finished to the lines, grades and cross sections

    as shown on the drawing. The subgrade shall be trimmed so that the level does not vary + 35mm

    from the level shown in the drawing.

    Compaction of Subgrade

    Compaction of natural ground shall be to the required density for a depth of not less than 200mm.

    For all earth fills the last 500mm layer of the subgrade below the granite base course over the

    area shall be compacted to a density of not less than ninety five percent of the maximum dry

    density obtainable using modified A-ASHO compactor test.

    At the time of compaction of each layer, the moisture content of the material shall be adjusted so

    as to obtain the degree of compaction specified. Water shall be added to material which contains

    insufficient moisture for compaction. The added water shall be sprayed uniformly and thoroughly

    mixed with material until a homogeneous mixture is obtained. Material containing excessive

    moisture shall not be compacted until the material has dried out sufficiently to obtain the required

    compaction.

    The whole subgrade surface of the road shall be consolidated with a wheeled roller of not less

    than 8 tons after the subgrade has been properly shaped and obtained and all unstable materials

    removed therefrom and replaced with approved materials.

    No sub-base material or granite base course material shall be laid on the driveway until subgrade

    has been inspected and approved for the laying of the sub-base or base course materials.

    The Engineer may require the test to be carried out at any location he deems necessary. The

    decision of the Engineer shall be final.

    Any material laid on the subgrade before the subgrade has been approved shall be removed from

    the site at the Contractor's expense. Work shall be so arranged that the final shaping and

    consolidation are carried out immediately before the foundation work so that the finished

    subgrade shall not be adversely affected by the weather.

    The base course of roads shall consist of 200mm compacted thickness of sledge granite blocks to

    be hand pitched and properly rolled.

  • S4/5 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Sub Base Course of Driveway (Contd)

    The grading of sledge granite block shall conform to the requirements described under the clause

    Grading of Materials. Blinding to the top of base course shall be a mixture of 1 part lateriate to 3

    parts of granite dust.

    The base course shall be well rolled with road rollers of 10 tons until the stones do not creep or

    wave ahead of the roller and until all granite blocks have firmly interlocked and a smooth

    uniform surface of the correct levels and cross-section has been formed.

    Any depression of 13mm or below a 3.0m long straight edge shall be remedial by loosening of

    the surface, adding or removing the road metal as necessary and re-rolling.

    Grading of Materials

    Laterite

    Laterite supplied by the Contractor shall be well graded material, suitable for road making

    containing a good proportion of course material. The grading of the laterite shall fall within the

    following limits:

    B.S. Sieve % Passing

    22mm 90 - 100

    13mm 66 - 100

    9mm 55 - 87

    5mm 35 - 60

    No. 7 30 - 50

    No. 14 28 - 46

    No. 25 26 - 42

    No. 52 23 - 38

    No. 100 22 - 34

    Before the commencement of the works three (3) representative samples of laterite shall be

    submitted by the Contractor from each approved source of supply. The tenderer shall furnish

    details in writing of such sources or sources of supply to the Engineer.

    Such samples shall be truly representative of the material to be supplied and shall be required to

    conform with the grading requirements as given in this specification.

  • S4/6 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Grading of Materials (Contd)

    Laterite (Contd)

    Where there is doubt as to the quality of the laterite being supplied at any time, grading tests shall

    be carried out as and where required by the Engineer. All inferior laterite may be rejected. The

    Contractor shall pay for the testing of all unsatisfactory samples.

    Sledge Granite Blocks

    Sledge granite blocks shall be hand picked from delivered loads of blocks ranging from 230mm

    down to minimum 75 mm but majority of blocks must be 230mm to 150mm and infill gaps with

    smaller sizes. An excess of flat granite shall not be used.

    Granite Spalls (75mm to 40mm)

    Broken stone or granite spalls shall extraneous matter. No particle is to to be such as no void will

    be left The following is an approximate grading: be hard, durable, clean and free from exceed

    75mm in size and the grading is after rolling with a 10/12 ton roller. The following is an

    approximate grading:

    B.S. Sieve % Passing (by weight)

    75mm 100

    40mm 85 - 100

    9mm 40 - 70

    5mm 25 - 45

    No. 25 8 - 45

    No. 200 0 - 10

    Granite (40mm to fine)

    Broken stone shall be similar to as described in the preceding paragraph.

    B.S.Sieve % Passing (by weight)

    50mm 100

    40mm 95 - 100

    19mm 45 - 100

    9mm 35 - 100

    5mm 25 - 100

  • S4/7 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Grading of Materials (Contd)

    Granite (40mm to fine) (Contd)

    B.S.Sieve % Passing (by weight)

    No. 25 8 - 65

    No. 52 5 - 40

    No. 200 0 - 10

    Wet Mix Asphalt Paving (Asphalt Concrete)

    Generally

    The Contractor shall lay 25mm premix asphaltic wearing course (Mix No. W3 and W4) on

    prepared roads surface as specified in Table 4.

    Binder

    All bitumen shall be approved asphalt bitumen of either 60/70 penetration and/or 80/100

    penetration (measured at 43o

    in both cases). All bitumen shall be straightrun prepared only by

    the refining of asphaltic-base petroleum and such refining shall not involve the "cracking"

    process. No mineral matter other than that naturally contained in such bitumen shall be present.

    The bitumen shall be of uniform quality, free from water and shall not foam when heated to

    195o

    C. The Contractor must state the country of countries of origin of all bitumen supplied, and

    the price paid for such bitumen prior to its use in the works.

    All bitumen to comply with the requirements given in Table 1 below:

    TABLE 1

    Item

    Description

    60/70

    Penetration

    Grade

    80 - 100

    Pentration

    Grade

    1.

    Penetration at 43 100 gms 60 - 70 80 - 100

    2. Flash Point Cleveland

    Open Cub)

    250

    (Min)

    236

    (Min)

    3. Loss on heating for 5 hours 1%

    (Max)

    1.5%

    (Max)

    4. Penetration after loss on

    heating 43 C

    100 gms (5 seconds)

    70% of Original

    Penetration

    70% of Penetration

    (Min)

  • S4/8 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Contd)

    Binder (Cont'd)

    All bitumen to comply with the requirements given in Table 1 below:

    TABLE 1

    Item

    Description

    60/70

    Penetration

    Grade

    80 100

    Pentration

    Grade

    5. Ductility at 43 at 5 cm

    per minute

    90 cm

    (Min)

    30 cm

    (Min)

    6. Solubility in Carbon

    Tetrachloride

    99.5%

    (Min)

    99.5%

    (Min)

    Tests for the above properties shall be carried out as far as practicable in accordance with the

    methods set out in the current edition of "Standard Methods of Testing Petroleum and its

    Products" as issued by the Institute of Petroleum.

    Mineral Fillers

    Mineral fillers shall consist of Portland Cement to BS No. 12 of 1958, and/or granite must of

    appropriate grading. At least 85% of cement filler and/or granite dust filler shall pass a No. 200

    B.S. sieve and filler shall be thoroughly dry and shall be free from organic matter and clay

    particles.

    Fine Aggregate

    This shall consist of approved clean, well-graded, fines produced in a secondary crushing plant,

    or approved clean natural sand property washed, free of all impurities.

    The grading shall comply with the requirements given in Table 2 below for wearing course

    mixtures:

    TABLE 2

    GRADING OF FINE AGGREGATE

    PASSING B.S. SIEVE

    WEARING COURSE MIXTURE

    Percentage by Weight

    5mm 100

  • S4/9 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Contd)

    Fine Aggregate (Contd)

    TABLE 2

    GRADING OF FINE AGGREGATE

    PASSING B.S. SIEVE

    WEARING COURSE MIXTURE

    Percentage by Weight

    No. 7 95-100

    No. 25 75-95

    No. 72 15-60

    No. 200 0-3

    Coarse Aggregate

    Coarse aggregate shall consists of clean, well-graded, crushed granite of approved quality, free

    from an excess of flat, elongated deleterious materials, and free from an excess of flat, elongated

    or weathered pieces. Coarse aggregate for the purpose of this Contract, shall be taken as all

    material retained on a 3mm British Standard Sieve.

    The grading of the coarse aggregate shall comply with the requirements in Table 3 below for

    wearing course mixture.

    TABLE 3

    GRADING OF COARSE AGGREGATE

    PASSING B.S. SIEVE

    NOMINAL THICKNESS

    38mm - 44mm

    Percentage by Weight

    51mm -

    38mm -

    25mm 100

  • S4/10 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Contd)

    Coarse Aggregate (Contd)

    The grading of the coarse aggregate shall comply with the requirements in Table 3 below for

    wearing course mixture.

    TABLE 3

    GRADING OF COARSE AGGREGATE

    PASSING B.S. SIEVE

    NOMINAL THICKNESS

    38mm - 44mm

    Percentage by Weight

    19mm 85-100

    13mm 0-100

    10mm 0-100

    6mm -

    No. 7 0-5

    Asphalt Mixing & Delivery

    The Contractor shall furnish the Engineer in advance with full details of all asphalt mixing

    plant(s) to be used, including average output capacity, type, age, maintenance facilities and all

    other relevant particulars required by the Engineer. The mixing plant to be used shall have an

    average output capacity of not less than 20 tons per hour.

    The approximate mix required shall comply with W3 and W4 of Table 4. Wherever considered

    advisable, the Engineer may vary the specified proportions of coarse and fine aggregates within

    the range of + 10% and the Contractor shall NOT be entitled to any extra payment nor suffer any

    reduction in payment on this account.

    The Engineer may vary the percentage filler to be use, within a range of + 2% and the Contractor

    shall NOT be entitled to any extra or reduced payment of this account.

    The Engineer may likewise vary the percentage of bitumen to be used, whereupon the price paid

    for the work shall be adjusted by him in accordance with the change in bitumen content ordered,

    based only on the net purchase price paid by the Contractor for the bitumen being used. If this

    price is greated than the ruling nett purchase price of bitumen at the time of variation, then the

    latter price shall be adopted for the purposes of calculating the value of any such variation.

  • S4/11 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Contd)

    Asphalt Mixing & Delivery (Contd)

    All aggregate of the requisite sizes and grading shall be throughly dried and fed at a temperature

    of 167C to 195C into a mechanical mixer of approved type. An accurately registering

    pyrometer shall be installed at a suitable point at the discharge end of the drier with a registering

    device so located as to indicate clearly the temperature of the coarse and fine aggregate when

    discharged. The bitumen shall be heated, in an approved type boiler, to a temperature of 153C to

    181C, and shall thereafter be added, together with the required proportion of filler, to the coarse

    and fine aggregated, and all ingredients shall be thoroughly and efficiently mixed together until

    complete coating of all aggregate and filler with the bitumen has been achieved. The Engineer or

    his authorised representative shall have access at all times to the asphalt mixing plant(s) and shall

    be at liberty to take such samples of materials as considered necessary from time to time to verify

    the proper operation thereof.

    If is particularly important to avoid excessive heating of the bitumen binder as this will lead to

    hardening of the binder and result in a shortening of the useful life of the pavement. In all case

    temperature should be kept as low as is consistent with proper mixing and laying.

    The asphalt, after proper mixing, shall then be discharged from mixer direct into a tipping truck

    of suitable dimension, for transportation to the worksite. The temperature of the mix on arrival at

    such worksite shall not be less than 139C. The Contractor shall provide an adequate number of

    accurate thermometers for checking the temperature of bitumen, hot mix, asphalt, etc. as directed

    by the Engineer.

    Vehicles used for transporting the asphalt shall be thoroughly cleaned free of all foreign materials

    immediately prior to loading with asphalt. The use of dirty or otherwise unsatisfactory vehicles

    shall render the load(s) of asphalt liable to rejection.

    Spreading & Finishing

    The Contractor shall furnish the Engineer in advance with full details of the mechanical

    spreader/finisher to be used, including date of manufacture, model, whether tracked or wheeled,

    previous usage, maintenance facilities, and all other relevant particulars required by the Engineer.

    The mechanical self-propelled spreader/finisher shall be capable of laying an asphalt carpet of

    not less than 3m width, and of being operated at varying rates of travel consistent with the rate of

    delivery and the type of asphalt mixture to be laid.

    On arrival at the site, the asphalt mix shall be tipped into the hopper of the mechanical

    self-propelled spreader/finisher and shall thereupon be spread, levelled, tamped and finished to

    correct profile, camber or cross-fall without causing segregation, dragging, burning or other

    surface defects or irregularities. The Contractor shall follow the Engineer's instructions as to the

    rate of travel of such machine at all times, and the spreader shall be operated at a uniform rate of

    travel and the mixture shall be fed to the spreader at such a rate as to permit continuous laying,

    insofar as the supply and site conditions allow.

    The spreader/finisher shall not operate on any type of side forms, but shall employ mechanical

    devices to adjust the grade and confine the edges of the asphalt to true lines.

  • S4/12 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Contd)

    Spreading & Finishing (Contd)

    Immediately after laying, and before rolling, the surface shall be checked and all irregularities

    and defects in alignment, grade, texture, etc. corrected in an approved manner.

    The surfaces, after final rolling, when tested with a straight-edge 3 metres long (placed parallel to

    the centre line of the carriageway) shall show no depression greater than 10mm. Preliminary

    rolling shall be carried out initially with a 2 to 5-ton roller, as soon as the asphalt mix has cooled

    sufficiently to support such roller without lateral flow of the mix. Finishing rolling shall be

    carried out with an 8 to 10 ton tanden roller or other suitable type of roller acceptable to the

    Engineer as soon as practicable after the preliminary rolling and shall proceed until no further

    compaction of the asphalt can be obtained. All rolling shall proceed at a sufficiently slow speed

    so as to avoid pushing or shoving of the asphalt carpet. The rollers shall not remain stationary on

    the warm asphalt carpet for any appreciable length of time. No oil shall be used on the wheels of

    any roller to prevent adhesion of asphalt. Sections of newly compacted asphalt carpet shall be

    protected from traffic for at least six (6) hours, or until properly hardened by cooling. The

    Engineer's requirements in this matter shall be final.

    All joints, both longitudinal and transverse shall be cut back square immediately prior to laying

    of further asphalt in contact with such joints, in order to ensure proper bond. All joints shall be

    finished uniform and true and free from depressions and projections of any description, and in

    particular the asphalt carpet shall not form any discontinuity at the commencement or completion

    points of the work.

    All manholes, kerbs, channels and other projections against which the asphalt mix is to be laid,

    shall be cleaned and a thin coating of bitumen emulsion applied prior to the laying of the asphalt.

    The mixture shall be carefully tamped around and against all projections by means of hot tampers

    of not less than 11.5 kgs. in weight and the finished surface left flush or, if required, up to a

    maximum of 3mm above such projections.

    Preparation of Surfaces

    Prior to the application of any prime or tack coat or spreading of the asphalt on any surface, such

    surface shall be thoroughly cleaned and dried, and kept free from any loose or otherwise surplus

    materials. Adherent patches or foreign material shall be removed from the surface by the use of a

    scraper of other suitable method. All waste materials removed from the surface shall be properly

    disposed of forthwith by the Contractor, failure to observe these requirements may result in

    payment being withheld.

    Tack Coats

    The Contractor shall supply and lay a suitable tack coat of bitumen emulsion at the rate of 1.800

    to 2.900 sq. metres per litre, as directed, to any surface, immediately prior to the spreading of the

    asphalt thereon, and after such surface has been thorouqhly cleaned and dried.

    The bitumen emulsion shall be applied by means of approved type of mechanical sprayer only,

    and shall be uniformly applied at the specified rate of application. Any excess or unevenly

    distributed bitumen shall be forthwith removed from the road surface at the Contractor's own

    expense.

  • S4/13 MTECH CONSULTANTS

    5. Road Works (Cont'd)

    Wet Mix Asphalt Paving (Asphalt Concrete) (Cont'd)

    Sampling & Testing

    Samples of asphalt mixtures shall be taken as, when and where considered necessary, by the

    Engineer, and testing shall, as far as practicable, be in accordance with British Standard 598 -

    Methods for the Sampling and Examination of Bituminous Road Mixtures.

    The cost of sampling and testing shall be borne by the Contractor and where test results are

    unsatisfactory, the Engineer may condemn all the asphalt represented by such unsatisfactory

    sample (s), or alternatively may, at his discretion, reduce the payment to the Contractor for such

    asphalt in accordance with the degree of departure of the test results from those required by this

    specification.

    The Contractor or his representative shall be entitled to be present during the carrying out of any

    tests, provided he shall have given one day's clear notice, on each occasion of such intention.

    The test results shall satisfy both the following requirements:

    (i) The percentage (%) of soluble bitumen in the mix of any and every sample should not be less

    than the minimum percentage specified.

    (ii) The average percentage of soluble bitumen of all the samples tested should also be not less

    than the average percentage specified.

    (iii) Where any of the test samples fails to comply with the requirement (i), all the asphalt

    surfacing represented by such unsatisfactory samples will be reiected and no payment shall be

    made.

    (iv) Where the samples fail to comply with the requirement (ii), a reduced payment for such

    asphalt surfacing shall be made to the Contractor. The amount of deduction will be decided by

    the Engineer based on the content of bitumen. The Engineer's decision shall be final.

    6. Kerbs

    Precast concrete kerbs 300 x 100 x 900mm long in Grade 20 concrete shall be laid in cast-in-situ

    concrete foundation backing in Grade 20 concrete at edge of driveway and road with top of kerb

    100mm above proposed finished level of road. Joints between precast kerbs shall be filled with

    cement mortar. The horizontal alignment of the kerbs shall not deviate by +-12mm from that

    shown in the Drawings nor deviate from the straight by more than +-3mm in 3 metres length.

    7. Channels around Buildings and Outfall Drains

    Surface water channels around buildings, covered ways, etc. shall be of in-situ or precast as

    shown on the drawings or as directed and finished internally and on top with 20mm thick cement

    and sand (1:3) trowelled smooth. Channels shall be laid on a bed of prepared sand or hard-core

    and where required, or if directed by the Engineer, reinforced with a layer of an approved fabric

    or rod reinforcement. Layout of channels shall be as shown on the drawings with all bends and

    junctions being carefully made to allow smooth and even flow. Minimum depth of channels shall

    not be less

  • S4/14 MTECH CONSULTANTS

    7. Channels around Buildings and Outfall Drains (Contd)

    than 150mm and minimum falls not less than 1 in 180 unless otherwise stated on the drawings to

    suit site conditions.

    Composite channel drain shall be approved precast concrete 'V'-shaped composite drains, with

    half round inverts and sides of the sizes as shown on the drawings and cast in 600mm lengths

    with 50mm diameter weep hole in each side of each length and laid to fall on a bed of sand of the

    thickness shown on the drawings with joints grouted and pointed in cement and sand (1:3).

    The composite channel drains shall be laid to the lines and depths as shown on the drawings and

    Grade 15 concrete lining shall be laid to the revetments above the tops of drains.

    Precast concrete cover slab of the sizes shown on the drawings shall be laid over surface water

    channels, cast in 600mm lengths with notched hand holes at both ends and reinforced with one

    layer of an approved fabric reinforcement. Cover slabs shall be set in rebates properly cut to left

    in the channel sides.

    8. Construction of Precast Concrete Drains, Pipes and Culverts

    The roadside drains shall be constructed section by section as directed by the Engineer and shall

    be generally completed before commencing work on the carriageway and kerbs. The precast

    units and sections shall be true to shape and of correct dimensions, finish and strengthened with

    required reinforcement wherever required. All precast units shall be approved for use by the

    Engineer before they are incorporated in any part of the works. Precast channels, pipe, revetment

    slabs, etc. shall be properly laid, bedded on a sand base at least 75mm thick unless otherwise

    stated and joints pointed with cement mortar. Side connections where required or shown on the

    drawings shall be formed and secured in concrete and/or cement mortar as directed and shall be

    finished to a smooth and uniform appearance. All precast drains, pipe and culverts shall be laid

    to a gradient as indicated on the drawings or as directed by the Engineer. Box culverts shall be

    laid on a sand base of at least 150mm thick compacted and screed off to the required level unless

    otherwise indicated on the drawings.

    9. Surface Water Drains

    Construct surface water drains along the sides of buildings, roads, etc. as shown on the drawings,

    constructed of 150mm thick sides and bottom with half round inverts and reinforced as detailed

    and rendered inside and on exposed surfaces with cement and sand (1:3) 19mm thick. Construct

    all necessary bends, junctions, etc.

    On completion clear all debris and clean drain to ensure that the entire surface water drainage

    system is in proper working order.

    10. Scupper Drains and Pipes

    Scupper drains and pipes shall be laid to the correct lines and levels from the kerbs to the

    roadside drains and shall be properly connected in cement mortar to the openings in the concrete

    kerbs and to the roadside drains. Revetment slabs and/or channels to the roadside drains shall be

    broken to take the outlet ends of scupper pipes and the connections made good in cement mortar.

    Each pipe

  • S4/15 MTECH CONSULTANTS

    10. Scupper Drains and Pipes (Contd)

    shall be properly bedded down and all butt joints sealed all round with cement mortar filleted up

    to form a collar 50mm wide by 25mm thick.

    Drop inlet chambers shall be provided at scupper pipe inlet along the carriageway all to LTA

    Standard Road Details for Street Works and its requirement.

    11. Test for Precast Concrete Culverts

    The Engineer shall have access to the casting yard where the precast concrete culverts are being

    manufactured. A copy of the manufacturer's test certificate shall be provided to the Engineer on

    demand. The precast concrete pipe culvert shall be test to SS 183.

    12. Grating, Manhole Cover and Frame

    All gratings over drains including framing shall be constructed as shown on the drawings. They

    shall be of hot-dip galvanizing in accordance with SS117: 1975.

    The manhole covers and frames shall be of the ductile cast iron machined type and of approved

    size, weight and pattern. The heavy duty type shall be used in roadways and paved areas.

    Manhole covers and frames are to be set in cement mortar and surrounded with Grade 20A (Class

    A) concrete and covers left flush with the surrounding ground or road surface as the case may be.

    Care shall be taken to ensure that the cover is level with and sloped to any fall or grade in the

    surrounding surfaces.

    Manhole covers and frames shall be supplied coated with a black bituminous composition.

    13. Gate

    Provide and hang gates and gate posts in positions and to details as shown on the drawings.

    Prepare, prime and paint one undercoat and two finishing coats enamel paint on surfaces of gates.

    14. Chain Link Fencing

    Provide galvanised chain link fencing 1,800mm high, consisting of No. 9 gauge x 50 x 50mm

    mesh pvc-coated chain link mesh and screen/slats with 3 lines of No. 5 gauge galvanised

    straining wire to match existing. The fencing shall fix to 63 x 63 x 6mm thick galvanised steel

    angle post at 3.0m centres and 38 x 38 x 6mm thick painted galvanised steel stay at alternate post,

    which is set in concrete footing.

  • CT1401B001 ANNEX B

    PROGRAM SCHEDULE Page 1 of 1

    PROGRAM SCHEDULE Contractor to submit a final program schedule and subject to SAS approval before commence work. Construction Period from date of award is not to exceed 5 months but can be extended with SASs approval. The attached program schedule is for guidance only.

  • CT1401B001PROGRAM SCHEDULEANNEX B

    SATS TRANSSHIPMENT DEVELOPMENT PROPOSED CONSTRUCTION PROGRAMPROPOSAL 1A - WITH SHELTER (CONSTRUCTION PERIOD: 5 MONTHS)Date : 16-Jan-14

    Note : For Full Works with Shelter

    ITEMS

    A TENDER AWARD

    B1

    a. Site Survey and Services Detection

    b. Site Setting Up

    c. Application of Permit to Commence Works

    2

    a. Site Clearing, Backfilling & Pegging Out.

    b. Services Works, Diversions, New Lines

    c. Foundation Works

    d. Steel Works

    e. Roof Works

    f. Finishing Works including Services

    g. External Works

    3

    a. Authority Inspections

    b. TOP & CSC

    3 4 1 3

    CONSTRUCTION

    Construction Works

    Completion & Inspections

    Preliminaries and Site Preparation

    23 4 2 3 4 1 21 231 1Mth 3 Jun 14 Mth 4 Jul 14 Mth 5 Aug 14Mth 1 Apr 14

    2 3 4 1 2Mth 2 May 14

    4Mth 7 Oct 14

    1 2 3 4Mth 6 Sept 14

    4

    WITH SHELTER Page 1

Recommended

View more >