building services, road construction

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BUILDING SERVICES, ROAD

CONSTRUCTION



BTEC HND In Quantity surveying Construction technology-B

CASE STUDY

The Y Company is a recently formed consultant firm and two recent projects

are assigned for their consultation. The description of two projects is given

below.

PROJECT A: A five storey residential building and a work shop

building.

A single storey factory building has to be constructed for the Z Company for

their production works. This factory building needs large span without

restrictions for their production work and approximately 20’ vertical

clearance. The construction work should be completed with short time

period. Your company has decided to use steel frame work for this building.In a part of this building a mezzanine floor has to be constructed for storing

facilities. For the floor of mezzanine structure, pre-stressed hollow core slabs

will be used.

TASK 01

Application of pre-cast concrete in construction of building.

Methods of construction of pre-stressed beams.Application of steel frame work in building with justification of selection of

steel frame work for the factory building

The standard steel section that you propose for each element of factory

building with proper sketches.

The method of connection of the members providing suitable sketches for

the connection of each member.

Fire protection methods available and fire protection method that you

recommend for the framework with proper justification of selected

method.




01. A.2 Why mostly use pre-cast concrete?

Provides predictable quality and structural characteristics because of factory

controlled conditions.

Timeliness:

Mass production as well as off-site production shortens project timeline,

allowing earlier occupancy. For example, the walls of a building can be

manufactured while on-site foundations are being built.

Strength:

Precast concrete is capable of higher strength which allows for long clear

spans making it especially applicable to structures requiring large open

spaces such as parking garages.

Safety:

The concrete provides superior fire resistance and sound control for

individual building elements and reduces fire insurance rates, especially

useful in multi-family housing.

Durable:

Provides long service for high use applications.

Secure:

Acts as a strong barrier for locations where security is an issue.

Sustainability

Pre-cast concrete has many environmental benefits during construction and

for the life of the structure. See associated sustainability solutions and

technical briefs (right) for more detail.




01. A.3 During construction

Waste Minimization:

Less material is required because precise mixture proportions and tighter

tolerances are achievable. Less concrete waste is created due to tight

control of quantities of constituent materials. Waste materials are more

readily recycled because concrete production is in one location. Sand and

acids for finishing surfaces are reused. Steel forms and other materials are

reused.

Recycled Content:

Recycled materials such as fly ash, slag cement, silica fume, and recycled

aggregates can be incorporated into concrete, thereby diverting materials

from the landfill and reducing use of virgin materials. Hardened concrete is

recycled (about 5% to 20% of aggregate in pre-cast concrete can be recycled

concrete). Gray water is often recycled into future mixtures.

Less Community Disturbance:

Less dust and waste is created at construction site because only needed pre-

cast concrete elements are delivered; there is no debris from formwork and

associated fasteners. Fewer trucks and less time are required for

construction because concrete is made offsite; particularly beneficial in

urban areas where minimal traffic disruption is critical. Pre-cast concrete

units are normally large components, so greater portions of the building are

completed with each activity, creating less disruption overall. Less noise at

construction sites because concrete is made offsite.




01. A.4 During the life of the structure

Energy Performance: Energy savings are achieved in buildings by

combining the thermal mass of concrete with the optimal amount of

insulation in pre-cast concrete walls. Pre-cast concrete acts as an air

barrier, reducing air infiltration, and saving more energy.

Disaster Resistant: Pre-cast concrete structures are resistant to

fires, wind, hurricanes, floods, earthquakes, wind-driven rain, and

moisture damage.

Cool: Light- or natural-colored concrete reduces heat islands, thereby

reducing outdoor temperatures, saving energy, and reducing smog.

Indoor Air Quality: Pre-cast concrete has low VOC remittance and

does not degrade indoor air quality.

Recyclable: Pre-cast concrete structures in urban areas can be

recycled into fill and road base material at the end of their useful life

01. A.5 Summery

Standard pre-cast products such as beams, decks, and railroad ties are

shaped in one type of form that is used repeatedly. Specialty pre-cast

products are designed for the particular building, bridge, or other structure.

Most pre-cast companies have their own carpentry shops where skilled

workers create forms for the specialty products. Architectural concrete is

often cast specially for each new project. During the production process,

forms for concrete are well lubricated. Concrete is placed in the forms and

allowed to cure. After curing, the product is carefully lifted from the form and

taken to a yard for further curing before it is shipped to the project site. The

form is cleaned and prepared for the next batch of concrete. Many pre-

casters can reuse their forms every one to two days. Exterior finishes for

architectural pre-cast concrete can incorporate a full range of colors and

textures. Textures are achieved by acid-etching, retarders, or sandblasting.




TASK 01.b

METHOD OF CONSTRUCTION OF PRE-STRESSED BEAM

Concrete is strong in compression, but weak in tension: its tensile strength

varies from 8-14% of its compressive strength. Due to such a low tensile

capacity, flexural cracks develop at early stages of loading. In order to

reduce or prevent such cracks from developing, a longitudinal force is

imposed on the structural element. This longitudinal force is called a pre-

stressing force. This compressive force pre-stresses the section along the

span of the structural element prior to the application of other loads.

This imposed force prevents cracks development at critical sections of the

element by reducing the tensile stresses thereby raising the bending, shear,

and torsional capacities of the sections. The sections are then able to behave

elastically, and almost the full capacity of the concrete in compression can

be efficiently utilized across the entire depth of the concrete sections when

all loads act on the structure.

01. B.1 Methods of pre-stressing

Basically there are two methods of pre-stressing.

• Pre-tensioning

• Post tensioning




01. B.1.1 In pretension, the steel is stretched before the concrete is

placed. High-strength steel tendons are placed between two abutments and

stretched to 70-80% of their ultimate strength. Concrete is poured into molds

around the tendons and allowed to cure. Once the concrete reaches the

required strength, the stretching forces are released. As the steel reacts to

regain its original length, the tensile stresses are translated into a

compressive stress in the concrete. Typical products for pretension concrete

are roof, slab, piles, poles, bridge girders, wall panels, and railroad ties.

01. B.1.2 In post-tensioning, the steel is stretched after the concrete

hardens. Concrete is cast around, but not in contact with outstretched steel.

In many cases, ducts are formed in the concrete unit using thin walled steelforms. Once the concrete has hardened to the required strength, the steel

tendons are inserted and stretched against the ends of the unit and

anchored off externally, placing the concrete into compression. Post-

tensioned concrete is used for cast-in-place concrete and for bridges large

girders, floor slabs, shells, roofs, and pavements.




01. B.2 Construction methods of pre-tensioning beam

Fig-01

Steel is tensioned between abutments.

Fig-02

The concrete is placed in moulds around it.

Fig-03

When the concrete has achieved sufficientcompressive strength; the steel is releasedfrom the abutments.




Fig-04 stages of pre-tensioning




01. B.2.1 Long line method

The most effective method is long line

production; where by a number of similar

units are produced at the same time.

The steel tendons are tensioned

between anchor plates at opposite ends

of a long stressing bed. These anchor

plates are supported by large steel

sections embedded in a blocks of

concrete at each end of a casting

surface.

Fig-05 long line method

The base slab mat act as a strut between these blocks of concrete but, with

long stressing beds, each block is made massive enough to remain stable; it

will not slip or rotate. At one end, the anchor plate bears directly into the

supporting joists is referred to as the fixed abutment. At the other end, the

jacking end, temporary steel struts are introduced between the anchor plate

and the supporting joists. The anchor plates are usually thick steel plates

with holes through which the wires or stands can be passed and anchored.

The ends of each unit will have a stop end, which will be drilled to the lay out

of the tendons required and for the size of wire or strand being used.

When the concrete has attained

sufficient strength, the temporary struts

are replaced by jacks who can be slowly

released.

Fig-05 long line method

As the tensioned steel tries to return to its original length, the bond between

the concrete and steel prevents this and so concrete is put in to




compression. Provided the units are free to slide along the bed, the tension

in the steel between the units is released, thus enabling the steel to be cut

quit safely at the ends of the units.




01. B.2.2 Stress bench method

The frame that is generally adopted in

a pre-tensioning system is called a

stress bench. The concrete mould is

placed within the frame and the

tendons are stretched and anchored on

the booms of the frame. The following

figures show the components of a

stress bench.

Fig-06 stress bench method

Fig-07 The free body diagram by replacing the jacks with theapplied forces.

Fig-08 The stress bench after casting of the concrete.




01. B.3 Construction methods of post-tensioning beam

1. Compressive forces are induced in a concrete structure by tensioning

steel tendons of strands or bars placed in ducts embedded in the

concrete.2. The tendons are installed after the concrete has been placed and

sufficiently cured to a prescribed initial compressive strength.

3. A hydraulic jack is attached to one or both ends of the tendon and

pressurized to a predetermined value while bearing against the end of

the concrete beam.

4. This induces a predetermined force in the tendon and the tendon

elongates elastically under this force.

5. After jacking to the full, required force, the force in the tendon is

transferred from the jack to the end anchorage.

6. Tendons made up of strands are secured by steel wedges that grip

each strand and seat firmly in a wedge plate.

7. The wedge plate itself carries all the strands and bears on a steel

anchorage. The anchorage may be a simple steel bearing plate or may

be a special casting with two or three concentric bearing surfaces that

transfer the tendon force to the concrete.

8. Bar tendons are usually threaded and anchor by means of spherical

nuts that bear against a square or rectangular bearing plate cast into

the concrete. For an explanation of post-tensioning terminology and

acronyms, see Appendix A.

9. After stressing, protruding strands or bars of permanent tendons are

cut off using an abrasive disc saw.

10. Flame cutting should not be used as it negatively affects the

characteristics of the pre-stressing steel.

11. Approximately 20mm (¾ in) of strand is left to protrude from

wedges or a certain minimum bar length is left beyond the nut of a bar

anchor.




12. Tendons are then grouted using a cementitious based grout. This

grout is pumped through a grout inlet into the duct by means of a

grout pump.

13. Grouting is done carefully under controlled conditions using

grout outlets to ensure that the duct anchorage and grout caps are

completely filled.

14. For final protection, after grouting, an anchorage may be

covered by a cap of high quality grout contained in a permanent non-

metallic and/or concrete pour-back with a durable seal-coat




Fig-09 procedure in post-tensioning construction




01. B.3.1 Equipment for pre-stressed beam construction

Fig-10 jack using for stressing

01. B.3.2 Grip assembly for pre-tensioning

SLA (Spring Loaded Anchor) Threaded grips should

normally be used at the non-stressing end of a bed,

but if prestressing is carried out using a jack

without power lock-off, spring loaded anchors

should also be used at the stressing end of the

bed. The threaded cap type anchor incorporates

the same type of wedge as the open grip, but has a longer barrel, a spring

and a threaded cap. Two threaded cap type anchors may be used with a

centre plug to form a double-ended joint. Used at the Dead End (Non-

Stressing) of the bed. Available is sizes; 3mm 4mm 5mm 6mm 7mm 8mm

9.6mm 11mm 13mm 15mm 18mm

The Open Grip is the most popular multiple use grip in use

throughout the world. It comprises a barrel and a wedge.

The wedge is in two segments for wire and three segments

for strand. The wedge segments are held together with a '0'

ring the grips are highly economical with few components

and may be inspected during use. They also provide ease

of detensioning and cleaning.Usedat the live end

(Stressing) of the bed. Available is sizes; 3mm 4mm 5mm 6mm 7mm 8mm

9.6mm 11mm 13mm 15mm 18mm




==Conclusion==

End of the task 01.b I gain the knowledge about, what is the 2 type of pre-stressed construction, what is the definition of pre-tension, post-tension

construction, , how to do the pre-tensioning, post tensioning construction,

what type of materials used to the construction. As well company decided to

include a mezzanine floor structure to build it by pre-stressed hollow core

slabs to use for storing facilities. Therefore it's the quick, easy, cost effective

way of installing a mezzanine floor and gaining the advantage of additional

room for extra storage.




TASK 01.c

APPLICATION OF STEEL FRAME WORKS IN BUILDINGS WITH JUSTIFICATION OF SELECTION OF STEEL FRAME WORK FOR THEFACTORY BUILDING

Today the cheapest proven construction method is steel. Many builders have

begun pre fabricating the buildings, which has further decreased

construction costs with steel buildings. Further benefits include fast

construction, reusable parts, and fire resistance. Another significant

advantage is steel's resistance to aging. Steel buildings can also be

constructed into a variety of buildings types, allowing for many uses.

Typically people imagine steel building being used for warehouses and

manufacturing. Steel have made great strides in their function ability and

style and are now often used for office buildings and even homes.

01. C.1 Benefits of steel

The physical properties of steel, such as its durability, flexibility and strength

offer significant advantages in the material efficiency of a product

application.

Steel is one of the most sustainable building materials with unique

characteristics that favour its use in the construction industry.

1. Steel for sustainable development

Steel has many significant advantages with regard to the demands of

sustainable development. In the construction sector, in which regulation on

environmental matters is becoming increasingly strict, it is vital to

communicate and demonstrate the advantages of steel to builders, specifies,

the authorities (regulatory bodies, in particular) and educators.




2. Steel for long lasting homes

The benefits of steel use and technologies in the homebuilding industry is

gaining momentum and creating additional customer value. The strength to

weight ratio of steel is the highest of any residential building material and itcan be easily formed and joined. Because steel is strong and lightweight, it is

beneficial for builders to work with and can be engineered to better

withstand hurricanes and earthquakes.

Steel is unique in that it is dimensionally stable. Unlike other materials that

shrink, expand, warp and twist with age to cause settlement cracks or floor

squeaks that require builders to make costly repairs.

3. Steel for architecture

Steel offers new solutions and opportunities, allowing architects to expand

their artistic expression and actually create some of the most challenging

buildings they have designed in their minds. Today it provides not only

strength to buildings, but also beauty and drama - enhancements that are

difficult or too costly to produce with other materials. Curving and bending is

now possible in ways that were never thought possible before. Curves using

steel beams bent to a certain radius or segmented curves or combinations of

both can create members that follow the outlines of irregular facades, arches

or domes.

4. Steel to build faster

The speed and accuracy of construction is critical to the creation of building

and stakeholder value. Earlier occupancy means an office owner can begin

renting space sooner, a factory owner can start producing products faster

and the store operator can bring in sales pounds quicker. Fast construction

also lowers financing costs and overhead expenses for construction

management services.




Because structural steel is lighter than other framing materials, it needs a

smaller and simpler foundation. This reduces both cost and the time spent

on construction.




5. Steel for earthquake safety

Earthquakes are unpredictable in terms of magnitude, frequency, duration,

and location. Consequently, the ideal structure to withstand earthquake

forces will behave in a consistent and predictable non brittle manner. Light

gauge steel framing is capable of meeting this standard due to its ductility

and the strict process used to manufacture steel studs, the inherent

properties of steel, and typical construction methods used in steel framing.

Building with steel should be considered at the top of the list to protect the

house against house damage and related consequences in case of

earthquake.

6. Steel to optimize space

Reducing storey heights will cut the costs for steel and other building

materials. From an energy-efficiency standpoint, minimising floor-to-floor

heights also helps curb heating and cooling costs. Running mechanical

systems through web openings is one solution for minimising building height.

Another way is integrating floor beams into interior walls or partitions. In

some cases, it is possible to limit the depth of beams by choosing a membersize that is shallower, though heavier, yet still offers the same required

strength.

'Slimflor' and the new Asymmetric Beam provide exciting new alternatives.

These both provide the opportunity to limit the depth of the floor to the

depth of the beam and the thickness of the concrete cover over the decking.

Steel's high strength-to-weight ratio enables it to span large distances

gracefully and economically - more so than any other building material.

In single storey buildings rolled beams can provide clear spans of over 50

metres, while using trussed or lattice construction can stretch this to more

than 150 metres.




The long spanning capability of steel also enables the creation of large areas

of unobstructed space in multi-storey buildings.

While short to medium span steel systems typically provide the lowest

structural frame construction costs, many clients are now demandingincreased flexibility which only steel can provide with column grid spacing of

15 metres and more.

Steel transfer girders may bridge two points to create column-free spaces by

eliminating columns. The Vierendeel truss, in particular, does not use any

diagonal members, which can inhibit sight lines and traffic flow.

Fewer columns make it easier to subdivide and customize living space for

current and future tenants. Open space also is more attractive to speculative

buyers and commands a premium price in a competitive market

7. Steel for flexibility

Building owners often are faced with the challenge of modifying an existing

space to meet changing needs - perhaps adding a new staircase, elevator or

column-free space, or even raising or lowering a ceiling. Changes may also

be necessary to comply with legislation such as the need to provide accessfor the disabled.

Steel is the only material that allows the strength of a structure to be

increased economically once it is built.

This is critical when a tenant would like to increase floor loads by adding

such things as file storage, computer systems, mechanical units or hospital

diagnostic equipment.

Non-composite steel beams can be made composite with the existing floor

slab or cover plates may be added to the beams for increased strength.

Additional steel may also be bolted or welded to the existing steel

framework.




Beams and girders can be easily reinforced, supplemented with additional framing

or even relocated to support changed loads.




Steel frame usually refers to a building technique with a "skeleton frame" of

vertical steel columns and horizontal I-beams, constructed in a rectangular

grid to support the floors, roof and walls of a building which are all attached

to the frame.

Single- storey lattice roof buildings

Single-storey rigid portal

Medium rise braced multi storey building

By using these three types’ structure steel frame buildings such as factories,

warehouses, flats, schools and transmission towers (etc). The building frame

is made up of separate elements the beams, columns, trusses, and bracing.

These must be joined together and building is attached to the foundations.

Structural steel elements, steel buildings are composed of distinct elements.

Beams and girders – members carrying lateral loads in bending and

shear.

Ties – members carrying axial loads in tension

Columns, struts – members carrying axial loads in compression

these members are often subjected to bending of struts and ties.

Trusses and lattice girders - framed members carrying lateral

loads. These are composed of struts and ties.

Purling - beam members carrying roof sheeting.

Sheeting rails - beam members supporting wall cladding.

Bracing - diagonal struts and ties that, with columns and roof trusses

from vertical and horizontal trusses to resist wind loads and stabilize

the building.

Joints connect members together such as the joints in trusses, joints between

floor beams and columns or other floor beams. Bases transmit the loads from

the columns to the foundations.




Symmetrical pitch lattice steel roof on columns structural steel Skelton frame

Common type of building

Application of steel for the propose factory building




Justification of selection of steel frame work for the factory building

In a building steel member can be used as a substitute material for the

construction of structural elements like column, beam, roof, etc… In the

particular factory building the construction should be completed quicker andthe height of the roof fairly high when compare to standard structural level.

In this case, as the steel having good strength characteristics and readily

available at any length or can be easily fabricated any length or position.

Also this has different verity of sections for multiple purposes. The steel

frame work could be the better option rather than going with conventional

reinforced concrete structures, as this would consume more time and need

some sort of complicated arrangement for high roof buildings.




TASK 01.d

THE STANDARD STEEL SECTIONS THAT YOU PROPOSE FOR EACHELEMENT OF FACTORY BUILDING WITH PROPER SKETCH

01. D.1 Standard rolled steel sections

The steel sections most used in structural steel work are standard hot rolled

steel, universal beams and columns together with a range of tees, channels

and angles illustrated.

Fig-11 standard rolled steel section




01. D.2 Hot rolled structural steel sections

Universal beams: These are very efficient sections for resisting bending

moment about the major axis.

Universal column: These are sections produced primarily to resist axial load.

Channels: These are used for beams, bracing members, truss members and

in compound members.

Equal and unequal angles: These are used for bracing members, truss

members and for purlins, side and sheeting rails.

Structural tees: The sections are produced by cutting a universal beam or

column into two parts. Tess are used for truss members, ties and light

beams.

01. D.3 Steel tubes and hollow sections

A range of seamless and welded seam

steel tubes is manufactured for use as

columns, struts and ties. The use of these

tubes as columns is limited by the

difficulty of making beam connection to a

round section column. These round

sections are extensively used in the

fabrication of lattice girders, frames, roof

decks and trusses. Hollow square and

rectangular sections are much used as the

members of lattice roof trusses and lightly

loaded framed structures with the square

sections for columns and the rectangular

sections as beams.

Fig-12 steel tube and hollow section




01. D.4 Cold roll formed steel sections

Cold roll-formed structural steel sections are made from hot rolled steel

strips which are passed through a series of rollers. As the strip is cold formed

it has to be passed through a series of rollers to avoid the thin materials

being torn or sheared in the forming process which produces sections with

slightly rounded angles to this end.

Fig-13cold

roll formed steel

section

01. D.5 Compound

sections

Compound sections are

formed by the following

means

• Strengthening a rolled section such as a universal beam by welding on

cover plates.

• Combining two separate rolled sections

• Connecting two members together to form strong combined members.

Fig-14 compound section




Justification for the selection of certain steel sections for main

members

Column: - Basically this member carries four side buckling possibilities, so

it’s important to resist those buckling moments. In

the available steel section the ‘’H iron’’ so called

universal column section would be a best

choice for the steel column, which has wider

flange and web. The size of the section will vary

with loading and height of the column.

Beam: - It’s slightly differs from the columns, mostly it has two dimensional

bending possibilities such as sagging and

hogging. So in this case there is no need for

wider flange section but it should have

sufficient web size to resist those loads. The ‘’Iiron’’ section so called universal beam

sections could be the suitable one for this type

of loading conditions

Roof: - This is assembled with collective of different steel section. Basically

in the roof truss unequal L iron section will be used. At the same timemembers like purline could be I section or box channel section.




TASK 01.e

THE METHOD OF CONNECTION OF THE MEMBERS PROVIDINGSUITABLE SKETCHES FOR THE CONNECTION OF EACH MEMBER

. There are three types of connection in structural steel work

Blots

Rivets

Welding

01. E.1 Bolts

There are three types of bolts

01. E.1.1 Black bolts

This type of bolts used end connections of secondary beams. The term of

black bolts does not indicate the colour. That is indicating the comparatively

wide tolerance to which these products are usually made. Black bolts and

nuts diameter range is 5-to 68mm.

01. E.1.2 Bright bolts

Bright bolts are sometimes called turned and fitted bolts. These types bolt

greater dimensional accuracy, fitting in to a hole with a small clearance

allowance.

01. E.1.3 High strength friction bolts

These bolts made by high-tensile steel and used in conjunction with high-

tensile nuts and tempered washers. This bolts are provide will transfer the

loads in the connecting members by fraction between the parts and not by

shear in, or bearing on, the bolts.




01. E.2 Rivets

Rivets made by mild steel. Rivets are available as either cold or hot forged

with a variety of head shapes (semi-circular or

snap head, universal or flat head). Today,

rivets fasteners are rarely used and bolts are

used as fasteners for site connections with

welding for some shop connections. Site

bolting required less site labor than riveting,

requires less skill, is quieter and eliminates fire

risk.

Fig-15 rivets

01. E.3 Welding

There are two types of welding methods available fillet or butt welds. The

methods of welding are oxy-acetylene and electric Fillet welds are used on

the edges and ends of members and form a triangular fillet of welding

material. Butt welds are used on chamfered end-to-end connections

Fig-16 Manual metal-

arc welding




Fig-17 Metal inert gas welding and submerged arc welding




01. E.4 Structural steel connections

These are either shop or site connections according to where the fabrication

takes place. Most site connections are bolted whereas shop connections are

very often carried out by welding. The design of structural steel work

members and their connections the province of the structural engineer who

selects the type and number of bolts or the size and length of weld to be

used according to the connection strength to be achieved.

01. E.4 1. Beam to column connection

These connections are made by

means of protruding studs or TS

welded to the columns and bolted

to the beams. Studs welded to

column are bolted to small

section beams and ties, and

larger section beams to tee

section cleat is welded to

columns, as illustrated. The T

section cleat is required for larger

beams to spread the bearing area

over a sufficient area of thin

column wall to resist bucking.

Fig-18 beam to column connection

Advantages

1. Frames are produced under factory controlled conditions resulting in a

uniform product of both quality and accuracy.

2. Repetitive casting lowers the cost of individual members.

3. Off site production releases site space for other activities.

4. Frames can be assembled in cold weather and generally by semi-

skilled labor.




Disadvantages

1. Although a wide choice of frames is available from various

manufacturers’ these systems lack the design flexibility of cast in-situ

purpose made frames.

2. Site planning can be limited by manufacturer’s delivery and unloading

programmers and requirements.

3. Lifting plant of a type and size not normally required by traditional

construction methods may be needed.

01. E.4 2. Column to column connection

Pre-cast columns are usuallycast in one length and can be

up to four store’s in height.

They are either reinforced with

bar reinforcement or they are

pre-stressed according to the

loading conditions. If column

to column are required they

are usually made at floor

levels above the beam to

column connections and can

range from a simple dowel

connection to a complex

connection involving in-situ concrete.

Fig-19 column to column connection

justification

Justification for selection of joints: In this construction, the mixture of bolt

and welding methods have adopted for joints. As this is a short period of




construction welding could be the best choice to work quickly, but some

cases still to be stick with bolt joints.




TASK 01.f

FIRE PROTECTION METHODS AVAILABLE AND FIRE PROTECTIONMETHOD THAT YOU RECOMMEND FOR THE FRAMEWORK WITHPROPER JUSTIFICATION OF SELECTED METHOD.

Building regulations are mainly concerned with controlling the spread of fire

to ensure the safety of those in the building and their safe escape in a

notional period of time that varies from a half – hour to six hours, depending

on the use of the building, its construction and size. Regulations also impose

conditions to contain fires inside compartments to limit the spread of flame.

One aspect of fire regulations is to specify notional periods of fire resistance

for the load bearing elements of a building so that they will maintain their

strength and stability for a stated period during fires in buildings for the

safety of those in the building. The larger the section of a structural steel

member, the less it will be affected by heat from by absorbing heat before it

loses strength.

The traditional method of protecting structural steelwork from damage by

fire is to cast concrete around beams and columns or to build brick or block

work around columns with concrete casing to beams. These heavy, bulky

and comparatively expensive casings have by and large been replaced by

lightweight systems of fire protection employing sprays, boards, preformed

casing and insitu-mescent coatings. The materials used for fire protection of

structural steel work may be grouped as;

• Spray coatings

• Board casings

• Preformed casings

• Plaster and lath

• Concrete, brick or block casings




01. F.1 Spray coating

A wide range of products is available

for application by spraying on the

surface of structural steel sections to

provide fire protection. The materials

are sprayed on to the surface of the

steel sections so that the finished

result is a lightweight coating that

takes the profile of the coated steel,

as illustrated.

Fig-20 spray coating

This is one of the cheapest methods of providing a fire protection coating or

casing to steel for protection of up to four hours, depending on the thickness

of the coating. The finished surface of these materials is generally coarse

textured and, because of the lightweight nature of the materials, these

coatings are easily damaged by knocks and abrasions.

1. Mineral fibre coating

2. Vermiculite / cement coatings

3. Intumescent coatings

01. F.1.1 Mineral fibre coating

Mineral fibre coatings consist of mineral fibres that are mixed with inorganic

binders, the wet mix being sprayed directly on to the clean, dry surface of

the steel. The material dries to form a permanent, homogenous insulation

that can be applied to any steel profile.

01. F.1 .2 Vermiculite / cement coatings

Vermiculite / cement coatings consist of mixes of vermiculite or aerated

magnesium oxychloride with cement gypsum plaster. The materials are




premixed and water is added on site for spray application directly to the

clean, dry surface of steel. These materials are somewhat more robust than

mineral spray coatings but will not withstand knocks.




01. F.1 .3 Intumescent coatings

These coatings include mastics and paints

which swell when heated to form an

insulating protective coat which acts as a

heat shield. The materials are applied by

spray or trowel to form a thin coating over

the profile of the steel section. They

provide a hard finish which can be left

textured from spraying or trowelled

smooth, and provide protection of up to

two hours.

Fig-21 intumenscent coating

01. F.2 Board casings

There is a wide choice of systems based on the use of various preformed

boards that are cut to size and fixed around steel

sections as a hollow, insulating fire protection. Board

casings may be grouped in relation to the materials

that are used in the manufacture of the boards that

are used as

1. Mineral libre boards or batts

2. Vermiculite / gypstum boards

3. Plasterboard

Fig-22 board casing




Fig-23 performed mineral fire protection




01. F.3 Preformed casing

These casings are made ‘L’ or ‘U’ shapes ready for fixing around the range

of standard column or beam sections, respectively. The boards are made of

vermiculite and gypsum, or with a sheet finish on a fire resisting lining, as

illustrated. The vermiculite and gypsum boards are screwed to steel straps

fixed around the steel sections and the sheet metal faced casing by

interlocking joints and screws.

01. F.4 Plaster and lath

Plaster on metal lath casing is one of the traditional methods of fire

protection for structural steelwork. The lath is covered with vermiculite

gypsum plaster to provide an insulating fire protective casing that is

trowelled smooth ready for decoration. This rigid casing can suffer abrasion

and knocks.

01. F.5 Concrete, brick or block casing

In situ cast concrete casing is the traditional method of providing fire

protection to structural steel work and protection against corrosion. This

solid casing is highly resistant to damage by knocks. This disadvantage is its

mass, which considerably increases the dead weight of the frame, and the

cost of onsite labour and materials in formwork.

Justification for fire protection method.

The mineral fiber coating has selected for the

fire protection method for the particular factory

building as this a quick construction and

possibility for knocking as this a factory or

workshop. So the selection of the fire protection

method should satisfy these both requirements.




Fig-24 mineral fibre coating




CONCLUSION

I made some visits to several construction sites and found some important details which the area

a Quantity surveyor must have some knowledge. I went to the site with the aim of having somekind of knowledge in building services

• I got most important details about steel structure and their connection methods water

supply, stack system, electrical work, sanitary appliances which replaced for it

• I came to know about some different services and their behaviors, their advantages and

disadvantages.

• And it gives the great experience to talk with senior Engineers and share their knowledge.

• I found alternative materials instead of normally used materials and also the origin of them for the road construction

• I learned how to read the BOQ for road construction

• I got to know how to select the sub base, base, type of surface for the road

• I realized the what are the types and components in bridge and their functions

This is the Assignment which gave me the practical site experience and some knowledge in

construction industry.




CONCLUSION

Lecture notes

Galwatta, B.S.L.K (2009) Building services. Colombo: British college of applied studies.31-pages handout, circulated 4th November 2009 in learningoutcome 2.

Referred books

Abeles, P. W. (1964). An introduction to prestressed concrete. London: Concrete Publications>

Andrew, R. P. and P. Witt (Eds.) (1951). Prestressed Concrete Statically Indeterminate

Structures. Cement and Concrete Association.>

Bazant, Z. P. and F. H. Wittmann (1982). Creep and shrinkage in concrete structures. JohnWiley.>

Burgoyne, C. J. (1988). Cable design for continuous prestressed concrete bridges. Proc. Inst. Civ.Engrs 85, 161{184.>

Cusack, P. (1984). Fran»cois Hennebique: the specialist organisation and the success of ferro-concrete: 1892-1909. Trans. Newcomen Soc. 56, 71{86.>

Web sites

[Cited 05 Jan2009]. Available from <www.brettmartin.com/.../roddingaccess.aspx>

[cited 05 Jan 2009]. Available from http://nett21.gec.jp/GESAP/themes/themes5_3.html

[cited 05 Jan 2009]. Available from <www.slotcosteel.com/mmrf.htm>

[cited 05 Jan 2009]. Available from <www.vhxn.com/.../>

[cited 05 Jan 2009]. Available from <www.cpci.ca/?sc=potm&pn=monthly102005>

[cited 05 Jan 2009]. Available from <http://www.whelansgroup.com/precast-piles-beams-wheel-

stocks.php>

[cited 05 Jan 2009]. Available from <http://www.ebawe.de/en/anwendungen/massiv-waende/?

navid=36>

[cited 05 Jan 2009]. Available from <http://www.acp-concrete.co.uk/Precast%20Concrete%20Bunker%20Walls.html>

http://www.brettmartin.com/building/underground/technical_guide/roddingaccess.aspx

http://nett21.gec.jp/GESAP/themes/themes5_3.html

http://www.slotcosteel.com/mmrf.htm

http://www.vhxn.com/samsung-bacteria-killing-air-conditioner-using-mpi-technology/

http://www.cpci.ca/?sc=potm&pn=monthly102005

http://www.whelansgroup.com/precast-piles-beams-wheel-stocks.php


http://www.ebawe.de/en/anwendungen/massiv-waende/?navid=36


http://www.acp-concrete.co.uk/Precast%20Concrete%20Bunker%20Walls.html


http://www.brettmartin.com/building/underground/technical_guide/roddingaccess.aspx

http://nett21.gec.jp/GESAP/themes/themes5_3.html

http://www.slotcosteel.com/mmrf.htm

http://www.vhxn.com/samsung-bacteria-killing-air-conditioner-using-mpi-technology/

http://www.cpci.ca/?sc=potm&pn=monthly102005







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