annex a - architectural & services works appendi… · annex a - architectural & services...

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 Consultant’s 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 Company’s 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


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-Contractor’s 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-

Contractor’s 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 Contractor’s Safety Officer of any special safety procedures in force and he will then

be responsible for training all the of the Contractor’s 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 Employer’s toilets, supply of water and power. F. SECURITY The Contractor’s 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

Employer’s premises.

CT1401B001


P3 - 3 -3

b) The Contractor shall at the reasonable request of the Employer’s 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. Consultant’s

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 manufacturer’s 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 Consultant’s 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 Contractor’s 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 Contractor’s 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 Employer’s 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


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 Contractor’s 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-contractor’s materials and plant, providing light to the nominated sub-contractor’s 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


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 Contractor’s proposal and will follow the BCA’s 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


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 Consultant’s 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


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 board’s 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


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 ½ 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


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 painter’s works shall be of the best grade and obtained from an approved manufacturer.

The Painter’s materials shall be used strictly in accordance with the manufacturer’s 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


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 manufacturer’s 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 manufacturer’s

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


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

manufacturer’s 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


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 manufacturer’s 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


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 Contractor’s 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 Contractor’s responsibility. f) Maintenance Recommendations Supply for Employer’s use, duplicate copies of manufacturer’s 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


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 manufacturer’s 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


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 Designer’s satisfaction and any work disturbed as a consequence shall be made good at the carpet Contractor’s 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 Employer’s use, duplicate copies of manufacturer’s 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


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


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 manufacturer’s 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


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 manufacturer’s 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 manufacturer’s 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


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


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


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 Contractor’s 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 Contractor’s 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 Contractor’s 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


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 110°C, 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

12φ

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


16 to 20


Over 22


(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 32°C at the time of placing.

(ii) Not exceeding 78°C during hydration at any time up to 14 days after

concreting.

(iii) Not exceeding 20°C 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 10°C 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/mm².

(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 20°C 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 (Cont’d)

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

Department’s 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

Contractor’s 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

Contractor’s 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 Contractor’s 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

Contractor’s 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 manufacturer’s 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 manufacturer’s 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

manufacturer’s 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 manufacturer’s 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

manufacturer’s 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 Engineer’s

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 day’s 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.


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.


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.


4. Aprons (Cont’d)

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.


5. Road Works (Cont'd)

Sub Base Course of Driveway (Cont’d)

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.



Grading of Materials (Cont’d)

Laterite (Cont’d)

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



Grading of Materials (Cont’d)

Granite (40mm to fine) (Cont’d)

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)



Wet Mix Asphalt Paving (Asphalt Concrete) (Cont’d)

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




Fine Aggregate (Cont’d)

TABLE 2

GRADING OF FINE AGGREGATE

PASSING B.S. SIEVE

WEARING COURSE MIXTURE


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


51mm -

38mm -

25mm 100




Coarse Aggregate (Cont’d)

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


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.




Asphalt Mixing & Delivery (Cont’d)

All aggregate of the requisite sizes and grading shall be throughly dried and fed at a temperature

of 167°C to 195°C 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 153°C to

181°C, 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 139°C. 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.




Spreading & Finishing (Cont’d)

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.



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


7. Channels around Buildings and Outfall Drains (Cont’d)

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


10. Scupper Drains and Pipes (Cont’d)

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 SAS’s 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