VOLUME 1 - Civil & Architectural Specifications

PROPOSED CAST ALUMINIUM PLANTAT KIZAD, ABU DHABI

VOLUME - 1

CIVIL & ARCHITECTURAL SPECIFICATIONS

DOCUMENT NUMBER: CAIPACESPECCA01DESCRIPTION DATE AUTHOR CHECKED BY APPROVED BY REV

Issued for Tender 21st August2014

Swaroop Abraham,Hani Akkari Faisal Majeed Faisal Majeed R0

CLIENT: MASTER DEVELOPER: DESIGN CONSULTANT:

Proposed Cast Aluminium Plant @ KIZAD, Abu Dhabi VOLUME 1: Civil & Architectural SpecificationsADM Project Number: 201355150 Revision Number: R0

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Section AA. Excavation and Earthworks


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1. EXCAVATION AND EARTHWORKS

1.1. Nature of Soil

1.2. Original levels

1.3. Site investigation report

1.4. Excavation

1.5. Finish of excavation and inspection

1.6. Removal of water

1.7. Sheeting and shoring

1.8. Storage and disposal of excavated material

1.9. Utilities trench excavation

1.10. Filling, back-filling and compaction

1.11. Soil improvement by Vibro-compaction.

1.12. Disposition of existing utilities

1.13. Safety of adjoining existing buildings/structures

1.14. De-watering

1.15. Site clearance

1.16. Demolitions

1.17. Blinding

1.18. Polythene Sheeting

1.19. Bitumen Treatment / Protection

1.20. Protective membrane to U/G Reinforced Concrete Structures

1.21. Depth of foundations

1.22. Anti-termite Treatment


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1. EXCAVATION AND EARTHWORKS

All Materials shall be of the best quality and to the approval of the Engineer in accordance to therelevant standards such as ASTM, British Standards, ACI, IBC-UPC and Agreement BoardCertificates noted in Specifications and the Local Authorities the ESTIDAMA CreditsRequirements to be fulfilled for obtaining the required Pearl Ratings for the Project.

Workmanship shall be to the highest required standards and codes of practices.

1.1. NATURE OF SOIL

The Contractor is to visit the Site and ascertain for himself the condition of the surface of theexcavations, previously completed by others and the type of substrata encountered in theexcavation.

The Contractor shall judge for himself the nature of the ground and shall be fully responsible forascertaining all necessary information concerning strain, permanent water table, periods ofrainfall, flooding of the site and all matters affecting the excavations and foundation work. Noextra will be allowed due to want of knowledge in this respect.

The methods of excavation which the Contractor desires to use shall be at the sole discretion ofthe Contractor.

The Contractor shall confirm to the Engineer that excavations are ready to receive foundationconcrete and shall obtain consent before depositing concrete. Any concrete deposited beforeconsent is given may, at the Engineers request, be broken up and removed at the Contractorsexpense and the work re-executed at no extra cost to the Employer.

In the event of additional excavation being made deeper than required, the Contractor shall fill inthe excavated void to the correct profile with hardcore or with sulphate resistance mass concreteas described in the "Concrete Work" Section hereinafter, at his own expense, and to thesatisfaction of the Engineer.

1.2. ORIGINAL LEVELS

A survey of the existing site excavation shall be made and the results of same submitted to theEngineer before commencement of the work.

1.3. SITE INVESTIGATION REPORT

Site investigation report has been carried out for the engineering design at the consultancy stage.The Contractor shall carry out his own further site investigation as required.

1.4. EXCAVATION

Excavation shall be carried out in all materials and by whatever means are necessary accuratelyto the lines and levels shown on the Drawings, or as ordered by the Engineer.

No blasting of any kind will be permitted without the written permission of the Engineer.

Slopes and formation surfaces shall be trimmed true to line and the required profiles shall be leftwell consolidated, neat and smooth.


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Any additional excavation occasioned by slips, falls, wash-ins, etc., shall be made good at theContractor's expense with mass concrete or approved filling materials as ordered by theEngineer's Representative.

1.5. FINISH OF EXCAVATION AND INSPECTION

The Engineer's Representative shall inspect all the excavations before commencement of furtherwork and the Contractor shall notify the Engineer's Representative when excavations are readyfor inspection.

The Engineer's Representative may instruct the Contractor to test the bearing capacity of the soilin the bottom of excavations. Upon receipt of such instructions, the Contractor shall forthwithcarry out such tests as the Engineer's Representative may instruct.

Should the bottoms of excavation be found to be unsuitable as bearing surfaces as a result ofsuch tests or inspection by the Engineer's Representative, the Contractor shall excavate further asdirected until a satisfactory bearing surface is achieved.

No excavation shall be refilled nor any permanent work commenced until the formation has beeninspected by the Engineer's Representative and his permission to proceed given.

1.6. REMOVAL OF WATER

The excavations shall at all times be kept free from storm water, percolating water or subsoilwater by means of de-watering Systems installed by the Employers previous contractor, andhanded over to the Main Contractor for continued operation. The Contractor shall provide,maintain and clear away on completion any equipment necessary together with temporary drainsand the like. Under no circumstances shall concrete be poured, fill placed, pipes laid orappurtenances installed in excavations containing water.

1.7. SHEETING AND SHORING

Shoring shall be provided where required, at the excavations to ensure complete safety againstcollapse of soil at sides of excavations, to provide protection of workmen and to prevent damageto adjacent property, structures, paving and utilities.

1.8. STORAGE AND DISPOSAL OF EXCAVATED MATERIAL

Any additional excavated material shall be removed from site.

1.9. UTILITIES TRENCH EXCAVATION

Utilities shall generally be installed in open cut trenches except that short connections may betunneled if in the opinion of the Engineer's Representative, the pipe or duct can be safely andproperly installed and back-fill can be properly placed and compacted in such tunneled section.

Bottom of trenches shall be graded evenly to secure the required falls for pipes and to ensurebearing over the entire length of the pipe. Bottoms of trenches shall be firm undisturbed soil,other than topsoil and free from rock, stones, hard substances, rubbish, and the like. Where rock,stones or other hard materials occur, these shall be removed for a depth of at least 150mm andthe space back-filled with selected sand or granular material compacted in accordance with back-fill requirements. No such material shall be excavated or back-filling carried out without theapproval of the Engineer's Representative.


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1.10. FILLING, BACK-FILLING AND COMPACTION

All filling material shall be imported. The imported filling material shall be sand and obtainedfrom an approved source in accordance with the latest instructions issued by the Department ofMunicipalities regarding the winning of material for filling. Imported filling material shallcontain no perishable or organic rubbish and no particles. The maximum dry density of thematerial shall be not less than 1600 kg/m.

Care shall be taken when filling or back-filling to avoid any wedging action or eccentric actionupon or against the structure of the work. Before placing of fill, the surface of the sub-grade shallbe compacted at optimum water content to the same percentage of maximum dry densityrequired of subsequent layers.

Filling and back-filling shall be placed in layers not exceeding 150mm thick (after compaction).Each layer shall be uniformly spread and shall be moistened or dried by aeration when requiredto ensure the optimum water content and shall be compacted uniformly by hand or machinemethods of specified density as follows:-

Filling under, At least 98%concrete beds, side walks maximum dryand other bearing situations density

Fill within 300mm, measured horizontally, At least 95%of foundation walls, retaining walls, maximum dryedges of footings, and other below-grade densityvertical surfaces. When machine compacted,compaction shall be by means of a 6 tonsmooth wheeled roller.

The Engineer's Representative shall have the right to disapprove any compacting device ofinadequate capacity or in his opinion, of type unsuited to the character of the material beingcompacted. Heavy equipment for spreading and compacting fill and back-fill shall not beoperated closer to walls than a distance to the difference in height between the top of the footingsand the layer being compacted

Testing to determine the density of in place soil shall be by means of ASSHTO Standard Methodof Test T147 or in accordance with BS 1377: 1975. The number of density tests per layer shallbe as instructed by the Engineer's Representative.

When back-filling behind retaining walls, basement walls and the like the said structures shall bekept propped during the complete operation. The hydraulic compaction of fill shall not bepermitted and the back-filling shall be carried out in layers not exceeding 150mm thick. Eachlayer shall be compacted to 90% of the modified compaction. No back-filling shall be carried outuntil the wall concrete has achieved its full works cube strength and care shall be exercised so asnot to damage the external tanking membrane and its protection.

Trenches shall not be back-filled until all required pressure tests have been performed and untilthe utility systems, as installed, conform to the requirements of the Specifications governingmechanical, electrical, and utility work.

Where, in the opinion of the Engineer's Representative, damage is likely to result fromwithdrawing sheeting, the sheeting shall be left in place. The trenches shall be carefully back-filled with approved back-filling materials, as herein before specified, deposited in 150mmlayers and thoroughly and carefully hand tamped until the pipe has a cover of not less than


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300mm for electric ducts, and 600mm for sewers and water mains. Where the pipe is speciallycoated for protection against corrosion, care shall be taken not to damage the coating. Theremainder of the back-fill material shall then be placed in 150mm layers, and compacted by handhammers or mechanical tampers to at least 90% maximum dry density. Settling the back-fill withwater will be permitted, and will be a requirement, when so directed by the Engineer'sRepresentative. Any trenches improperly back-filled, or where settlement occurs, shall bereopened to the depth required for compaction, then refilled and compacted, with surfacerestored to the required grade and compaction, mounded over and smoothed off.

Open trenches across parking areas and trenches at other areas to be paved shall be back-filled asspecified above, except that the entire depth of the trench shall be back-filled in 150mm layersand each layer shall be moistened and compacted to at least 98% of maximum dry density, toprovide the required bearing value, so that construction or paving over the area can proceedimmediately after back-filling is completed. Along all other portions of the trenches, the groundshall be graded to a reasonable uniformity and the mounding over of the trenches left in auniform and neat condition to the satisfaction of the Engineer's Representative.

Field control density tests shall be made by the Contractor as directed by the Engineer'sRepresentative to determine the degree of compaction being obtained by field compactionprocedures during construction of sub grade. Each lift of material placed by the Contractor shallbe subject to the approval of the Engineer's Representative. No material shall be placed on aprepared sub grade, without the prior acceptance of the sub grade by the Engineer'sRepresentative. Sub grade shall be compacted throughout to 98% of maximum density atoptimum moisture content.

Compaction equipment shall consist of smooth power rollers or other equipment which willproduce the compaction 7kg/cm2. No compaction equipment may be employed for thepermanent work without the approval of the Engineer's Representative. Material in the layersshall not be compacted when the moisture content is more than 2 percentage points above or 3percentage points below the optimum moisture content except for cohesive materials for whichno optimum point can be obtained.

If the material is too dry, immediate steps shall be taken to rectify the situation and no additionalmaterials shall be placed until the compaction can be resumed and the required moisture contentand densities required can be met. If the material is too wet, compacting work and placement ofadditional fill shall be delayed until the material has dried to the extent that the required moisturecontent will be required through the layer for the particular soil involved, wetting or drying andmanipulation of the material will be required, if necessary, to accomplish this objective. Duringthe progress of the work, the Engineer's Representative will inspect the material as to type,condition, moisture content and densities, and may direct the location of its placement in the fill.The compaction of each layer shall be completed both in widths and longitudinal extent beforethe next lift is started. The quantity of material being placed shall not exceed the capacity of thecompaction equipment. The Contractor shall make "in place" density and moisturedeterminations and the Engineer's Representative will approve the compaction and moisturecontents of each layer. The distribution of materials shall be such that the compacted materialswill be free from lenses, pockets, streaks or other imperfections. Based on unsatisfactory resultsof 'in place' density and other moisture tests, the Engineer's Representative will require theContractor to obtain the specified valued for these items, including, if necessary, replacement ofwork. The Contractor shall be responsible for the stability of all fill made under the Contractuntil the work has been accepted by the Engineer's Representative and shall replace any portionwhich, in the opinion of the Engineer's Representative has become displaced.


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Compact fill shall consist of approved materials obtained either from excavations or from otherapproved sources. Compacted fill shall comprise suitable granular materials well graded andshall not include perishable matter or an excess of fines and should give a dense fill layer.The material shall be free of organic matter and have the following properties:

Minimum Soaked CBR of 15% when he material is compacted to 95% of the maximumdry density.

Insitu CBR of 10% when the compacted layer is field tested at site.

Liquid Limit not more that 35% and plasticity index not more than 6%.

Linear Shrinkage not exceeding 3%

Water Soluble Salts not more than 0.5% by weight of dry material.

Organic Materials no organic material permissible

Maximum Particle Size not more than 75 mm; max passing sieve No.200 < 30%

Lab CBR Tests as determined by Test 16, BS 1377.

Sulphate Content as per BS 1377 0.5% maximum.

Chloride Content as per BS 812 1% maximum.

Field Density Test as determined by Test 15B of BS 1377.

Linear Shrinkage Test as determined by AASHTO T92: Not to exceed 3%

Organic Matter Test as determined by Test 8 of BS 1377.

Maximum Dry Density at Optimum Moisture Content as determined by Test 13, BS1377, but not less than 1600 kg/m3.

Liquid Limit as determined by BS 1377; 1975: 2.2 (Test 2 A : Preferred method usingthe cone penetrometer)

Plasticity Index as determined by BS 1377: 1975 2.4: Less than 6%

Prior to any approval of the source of fill material, tests will be performed to ascertain that thematerial complies with the above minimum requirements. Subsequently if different material is tobe used other than the approved one, new tests shall be carried out.

Tests for Density and Compaction

The following gives the minimum testing required for fill. Additional or more frequent tests maybe required if materials vary or workmanship is inconsistent:

a) Laboratory tests for MDD, optimum moisture contents, for each layer.

b) Field density and moisture content, insitu CBR, for each layer as required by the Engineer.

The areas shall be rejected if the resulting test results do not satisfy specified requirements.


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1.11. SOIL IMPROVEMENT BY VIBRO COMPACTION.

Vibro-compaction is a ground improvement technique that densifies clean, cohesion-lessgranular soils by means of a down-hole vibrator.

The vibrator is typically suspended from a crane and lowered vertically into the soil under itsown weight. Penetration is usually aided by water jets integrated into the vibrator assembly.After reaching the bottom of the treatment zone, the soils are densified in lifts as the probe isextracted. During vibro compaction, clean sand back-fill is typically added at the ground surfaceto compensate for the reduction in soil volume resulting from the densification process. Thevibratory energy reduces the inter-granular forces between the soil particles, allowing them tomove into a denser configuration, typically achieving a relative density of 70 to 85 percent. Thetreated soils have increased density, friction angle and stiffness. Compaction is achieved aboveand below the water table.

The improved soil characteristics depend on the soil type and gradation, spacing of thepenetration points and the time spent performing the compaction. Generally, the vibrocompaction penetration spacing is between 1.8 m and 4.3 m, with centers arranged on atriangular or square pattern. Compaction takes place without setting up internal stresses in thesoil, thus ensuring permanent densification.

The use of clean sand back-fill during vibro compaction allows the original site elevation to bemaintained. However, on sites where the planned final grade is below the existing grade,lowering of the site elevation may be desirable. In these instances, the ground surface is allowedto subside during the compaction effort.

Vibro-compaction permits the use of economical spread footings with design bearing pressuresgenerally of 240 kpa up to 480 kpa .Settlement and seismic liquefaction potentials are reduced.The required treatment depth is typically in the range of 4.5 to 15 m. Examples of previouslyperformed applications include increasing bearing capacity, decreasing settlement and mitigatingliquefaction for planned structures, embankments, railways and roadways.

Vibro-compaction rigs can be fully instrumented with an on-board computer to monitorparameters during vibro-compaction. Monitoring these parameters allows the operator to correctany deviations in real-time during the construction process to keep the vibro compaction withinproject specifications. Data from the Data Acquisition (DAQ) system such as amperage and liftrate are recorded and displayed in real-time alongside specified target values on an in-cabmonitor.

1.12. DISPOSITION OF EXISTING UTILITIES

Before commencing any construction work, the Contractor shall obtain from the various utilitiesDepartments, Companies or Employer the location of any existing utilities on the Site. Activeutilities on the Site shall be carefully protected from damage, relocated or removed as requiredby the work. When an active utility line is exposed during construction, its location and elevationshall be plotted on the Record Drawings and both the Engineer's Representative and the utilityowner notified in writing.

Inactive or abandoned utilities encountered during construction operations shall be removed,plugged or capped. The location of such utility shall be noted on the Record Drawings andreported in writing to the Engineer's Representative.

Active utility lines damaged during the course of construction operations shall be repaired orreplaced as determined by the Engineer's Representative at the Contractor's expense.


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Immediately, when an active utility line is damaged, the Contractor shall notify the Engineer'sRepresentative and the utility owners by telephone and in writing.

1.13. SAFETY OF ADJOINING EXISTING BUILDINGS/STRUCTURES

The Contractor shall take all necessary precautions during the excavation for the Worksparticularly those excavation which are adjoining existing buildings/structures and shall protectsuch buildings/structures from the damage or collapse by means of temporary or permanentshoring, strutting, sheet piling or underpinning or excavation in short lengths and/or othermethods as he deems fit also he shall properly support all foundations, trenches, walls, floors, etc.affecting the safety of the adjoining existing buildings/structures.

The Contractor shall alter, adopt and maintain all such works described above for the wholeperiod of the Contract and shall finally clear away and make good all damages done.

The construction and efficiency of the shoring, underpinning, strutting and the like for thepurpose for which it is erected shall be the responsibility of the Contractor, should anysubsidence or any other damage occur due to the inefficiency of the shoring, underpinning,strutting and the like or any other support provided, the damage shall be made good by theContractor at his own expense and responsibility.

The shoring, strutting, piling and the like, shall be executed in such a manner as to cause as littleinconvenience as possible to adjoining owners or the public and the Contractor shall beresponsible for negotiating with the adjoining owners the means to safeguard their property andfor the use of any portion of their land for the purpose of executing the excavations and noclaims submitted on this ground will be entertained.

The Contractor shall be held solely responsible for the safety of the adjoining existingbuildings/structures the sufficiency of all temporary or permanent shoring, underpinning, piling,and the like. The Contractor shall keep the Engineer informed as to manner in which he intendsto proceed with the execution of the excavations and obtain his approval, such approval if givenshall not absolve the Contractor of his responsibility under this Clause.

The Contractor shall save harmless and indemnify the Employer in respect of all claims,demands, proceedings, damages, costs, charges and expenses whatsoever arising out of or inrelation to any such matters in so far as the Contractor is responsible under this Clause.

1.14. DE-WATERING

Surface water and ground water shall be prevented from flowing into excavations and fromflooding the project site and surrounding areas.

Water shall not be allowed to accumulate in excavations and the Contractor shall provide andmaintain pumps, well points, sumps, suction and discharge lines, and other de-watering systemcomponents necessary to continuously convey water away from excavations.

Temporary drainage systems, pumps and/or other diversions outside excavation limits shall beestablished and maintained to convey rain water and water removed from excavations todischarge locations.

Surface and subsurface water encountered in the course of the work shall be collected andproperly disposed of.


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The Contractor shall maintain adequate supervision and control, to ensure that stability ofexcavated and constructed slopes are not adversely affected by water, erosion is controlled;flooding of excavation or damage to structures does not occur.

The Contractor shall ensure that groundwater removal will not cause settlement of adjacent soil,or any displacement, settlement or damage to permanent and temporary works, existingstructures, roads, utilities and other property. He shall monitor conditions at all times todetermine that no soil or fines is removed in the pumped water which would cause displacement,settlement or damage.

Water removed from excavations shall be disposed of in a manner to avoid endangering publichealth, property and portions of work under construction or completed. Sumps, sedimentationtanks, oil separators, and other flow control devices shall be provided as required by LocalAuthorities.

Settling tanks are to be provided to collect earth fines and other sediment from pumped waterbefore it enters the discharge system. Tanks are to be cleaned out on a regular basis to ensurethat only clear water is discharged by the system.

The water pumped from the excavations or well points shall be conveyed to a discharge locationapproved by the Local Authorities. Under no circumstances may water be disposed of in theMunicipality's foul sewer system.

Stand-by equipment is to be provided on site, installed and available, for immediate operation ifrequired to maintain de-watering on a continuous basis in event any part of the system becomesinadequate or fails. If de-watering requirements are not satisfied due to inadequacy or failure ofde-watering system, extra equipment has to be installed at no additional cost to the Contract.

1.15. SITE CLEARANCE

The site shall be given to the Main Contractor clear of all obstructions.

1.16. DEMOLITIONS

Demolition includes the complete demolition including grubbing up of foundations and theproper termination of all services as required by the Drawings including the removal anddisposal of all demolished materials. The demolition work shall be executed in a systematicmanner.

Demolition operations and the removal of debris shall be carried out to ensure minimuminterference with roads, streets, footpaths and other adjacent occupied or used facilities.

The Contractor shall be responsible for removing all kerb footings etc. In this respect he shallliaise with the respective department at the Municipality, gain the necessary permission, paymentof fees as applicable before commencing this item of work.

Damage caused to adjacent facilities by demolition operations shall be repaired by theContractor at his own expense. The Contractor shall arrange and pay for the disconnecting,removing and capping of utility services, notify the affected utility agency in advance and obtainwritten approval before commencing work.


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1.17. BLINDING

The Contractor shall lay min. 100mm blinding to excavations generally as directed afterinspection of the excavations by the Engineer. Sand blinding shall be clean sand obtained froman approved source, crushed stone blinding shall be well graded from 10mm to dust and obtainedfrom an approved source, concrete blinding shall be sulphate resisting concrete (1:2:4 mix) asspecified in "Concrete Work" Section and on the drawings.

The surface of the blinding shall be floated smooth to receive the building waterproofing systemor polythene sheeting in other areas.

1.18. POLYTHENE SHEETING

Cover the whole of the area beneath concrete slabs, other than the raft foundation, and elsewheredirected by the Engineer with polythene sheeting. The polythene shall be 1000 gauge nominalweight 0-94 kg per sq meter manufactured by a manufacturer and shall be approved by theEngineer.

The sheet shall be supplied in rolls and laid by rolling over the prepared base at the levels and inthe areas shown on the drawings. Joints at the side or end of a sheet shall be 450mm wide doublewelts made by placing the edges together and folding over twice. The joints shall be preventedfrom opening prior to concreting by blocks placed at intervals on top of the joint.The Contractor shall protect the sheets from damage during laying and subsequent operationsand shall replace all damaged sheets to the satisfaction of the Engineer.

1.19. BITUMEN TREATMENT/PROTECTION

Unless shown otherwise, all surfaces of concrete or block work shall be painted with 3 coats ofbitumen. This shall be cold applied by rollers to give a minimum thickness of 2mm to thesatisfaction of the Engineer.

1.20. PROTECTIVE MEMBRANE TO U/G REINFORCED CONCRETE STRUCTURES

All surfaces of foundations, or where indicated on drawing shall be protected by a proprietarywaterproof membrane system as described in Particular Specifications. The membrane is to bespecified and to be protected by protective board to the approval of Engineer.

1.21. DEPTH OF FOUNDATIONS

The foundations shall be the minimum depth below original ground level shown on the drawingsand soil investigation report.

1.22. ANTI-TERMITE TREATMENT

1.22.1. General

Work shall be carried out by a qualified specialist sub-contractor registered in the UAE.The specialists sub-contractors shall be from the list of approved manufacturers /suppliers or equal approved.

The Sub-contractor shall be responsible for all the pre and post termite treatment for theconstruction. The Sub-contractor shall make all necessary arrangements for and provideall necessary attendance to the Pest Control Section, if required.


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The Sub-contractor shall carry out the pre and post treatment work for anti-termitecontrol to include the whole of the site areas within the areas defined by the contractlimit lines.

1.22.2. Scope of Works

The Contractor shall survey the sites before tendering to ascertain the nature and extentof the work involved for anti-termite treatment and any conditions and restrictionslikely to affect the execution of the works. Work consequent upon treatment, but notincluded in the tender, is to be clearly identified as such. The Contractor shall ensurethat the sites are adequately prepared before treatment commences.

Prior to application of the treatment on site all chemical dilution samples andcomputations shall be submitted for approval with a copy of the submission furnishedto the Engineer.

Samples of materials, chemical applicator and protective clothing and accessories shallbe provided together with all necessary certificates for approval by the Engineer and AlAin Municipality, if required.

Samples shall not be incorporated in the works but kept intact for the duration of thewhole contract period for purposes of comparison with the works carried-out. Samplesfrom manufacturers shall be in the manufacturers packaging sealed and unopened.

A work programme shall be prepared taking into account and coordinating all otherrelated works and shall be submitted for the Engineers approval.

The Sub-Contractor shall submit a list of chemicals and their respective manufacturerstechnical literature.

The Sub-Contractor shall submit a Method Statement for carrying out the works to theEngineer for approval and the works shall be carried out as per the method statement.

The Sub-Contractor shall keep all the working areas clean and shall keep all chemicalsand tools/machineries in a safe place each day after works are completed.

Clear warning notices shall be posted at the entrance to the site during treatmentoperations and immediately following completion. The sign shall show the name of thepesticide being utilized and date of application.

Materials shall include the supply of all chemicals, water, tools, equipment, machineries,protective clothing and emergency items and clear procedures to be followed for healthand safety in case of accident including all necessities to complete the applicationeffectively and safely.

The Contractor shall prepare as built drawings for walls, floor slabs and other areastreated with residual chemicals and shall submit 4 copies of the drawings to theEngineer, together with Contractors guarantee certificate.

The Contractor shall provide 4 copies of all documents for submission to the Engineeras required, unless specified otherwise.


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1.22.3. Procedures

All pre and post termite treatment works shall be in accordance with the bestinternational pest control practices, paying special attention to safety of workerscarrying out the works and all staff and personnel within the construction site.

Specifically, all chemicals, equipment, machineries used or supplied and allworkmanship shall be in accordance with the appropriate practices of the British PestControl Association (BPCA) and the National Pest Control Association of the UnitedStates of America (NPCA) and the related requirement of the World Pest ControlOrganization (WPCO) and the European Community Council (ECC) guidancedirectives on the use of pesticides, unless otherwise approved.

The Sub-Contractor shall note that the Engineer does not have suitably qualified andcertified personnel to make any recommendations on the use and choice of pesticidesand such responsibility shall remain solely with the Sub-Contractor.

The Sub-Contractor shall obtain the advice of a suitably qualified person prior to theuse of any pesticide. Such advice shall be taken into account in all respects and fulldetails and recommendations shall be provided to the Engineer prior to the applicationof pesticides on the site.

The Sub-Contractor shall be entirely responsible for the choice, application and storageof any pesticides utilized for the works all of which shall conform to standard practicesrecognized by BPCA and/or NPCA or as approved.

The Contractor shall use a qualified and locally certified technician and operator toapply the pesticides in accordance with all local and international legislation.

The Contractor shall give the Engineer 3 weeks minimum notice on the proposedapplication of pesticides, giving details of the purpose, chemical dose rate, method ofapplication, proposed application dates, and 4 copies of the appropriate current productinformation.

The Contractor shall keep full and accurate records of all pesticides used. Records aftereach application and a summary recorded at the end of the contract shall be provided toEngineer.

The Contractor shall dispose of all empty containers and unwanted chemicals includingall surplus diluted tanked mixture, to an off-site location approved by the Engineer.

All areas shall be made clean during and after work operations. No chemicals, dilutedsolutions or equipment shall be left unattended during and after working hours.

During lunch break, works are to be secured and supervised by visible sign boardswhich shall be provided before and after chemical applications. Contractor to prepareand submit pesticide work safety program. This program shall include the following:

Advise as to how pesticides can harm human beings, animals, vegetation.Instruction, training and supervision of pesticide workers.Emergency care if an accident occurs.Medical supervision routine following an accident or illness.Special instructions restricting employees handling toxic pesticides.Personal hygiene.


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Protective clothing.Safety equipment (personal).Safety requirements for pesticides application equipment.Maintenance of pesticide application equipment.Safety of field workers, general public, animals, vegetation and property.Protection of the soil and environment.

Copies of the following certificates shall be provided to the Engineer for acceptance ofthe chemicals to be utilized and a method statement for applications.

Certificate from any of the Emirates within the UAE to certify that the said applicatorcompany is an authorized and certified pest control contractor.

Importation, transportation and any certification for all chemicals and materialsrequired by national and/or local laws, unless otherwise approved.

Chemical certificate confirming the certified analysis of the chemicals to be used andlisting the proportions of the various ingredients, as declared by the originalsupplier/manufacturer and by the approved testing laboratory.

All pre and post termite treatment applications shall be carried out in appropriate seasonand weather conditions.

If during the application of chemicals the weather condition changes making conditionsunfavourable to works being carried-out, the contractor should immediately stop theworks and apply the contingency plan approved by the Engineer.

The Contractor shall ensure proper co-ordination of all pre and post termite treatmentapplications in relation to the carrying-out of associated works on site.

Such co-ordination must be approved in advance by the Engineer.

Chemicals shall be stored in a separate locked storeroom with proper ventilation systemapproved by the Engineer.

Contamination of materials due to contact with other materials or alien substances shallbe avoided. Contaminated material shall be immediately removed from site. Materialdetrimental to humans, animals and plants shall be stored separately.

Storage areas and protection of stored materials shall be agreed with the Engineer inadvance of the works.

During lunch break, the works are to be secured and supervised by a qualified memberof the staff.

Visible sign boards are to be provided before and after each application.

The Sub-Contractor shall submit a written, 10-year guarantee made out to the Ownerand jointly signed and sealed by the main Contractor, guaranteeing safety of thebuilding and surrounding areas against termite infestations.


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Section AA1. Piling


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PILING WORKS

1.0 SCOPE OF WORK

The works comprise the construction of reinforced concrete piles in the positions shown on thedrawings.

2.0 STANDARDS

All Materials shall be of the best quality and to the approval of the Engineer in accordance tothe relevant standards such as ASTM, British Standards, ACI, IBC-UPC and AgreementBoard Certificates noted in Specifications and the Local Authorities, also the ESTIDAMACredits Requirements to be fulfilled for obtaining the required Pearl Ratings for the Project.


Safety regulations throughout the piling operations shall comply with the standards previouslylisted.

3.0 GUARANTEE

The Contractor shall guarantee unconditionally in writing that each and every pileinstalled will safely carry the maximum working load as stated on the drawings. In additionhe shall guarantee that a load of at least 1.5 times the working load can be carried by each andevery pile without progressive settlement or creep.

It should be noted that the performance of satisfactory pile tests on the site (as specifiedbelow) does not release the Contractor from responsibility, liability or consequence arisingin the future due to unsatisfactory performance of the foundations which can be attributedto the piles

4.0 SPOIL AND RUBBISH DISPOSAL

The Contractor shall include in his work for the prompt removal from site of any spoilremoved from the pile bores and upon completion of the works shall clear away all spoil andrubbish and leave the site clean and to the satisfaction of the Engineer

Disposal of drilling mud is the responsibility of the Contractor. It must not be deposited intothe local drainage system etc. The ground water may be removed by passing throughsettlement tanks and disposed in accordance with local authority regulations and to theapproval and satisfaction of the Engineer.

5.0 SETTING OUT

The Contractor will be responsible for setting out the base lines and pile positions andestablishing datum and cut off levels as shown on the Engineer's drawings.

A maximum tolerance of 50 mm in any plan direction may be permitted in the position of anypile. The maximum permitted deviation of the finished pile from the vertical is 1 in 100. Ifthese tolerances are exceeded, the Contractor shall be responsible for the cost of andproviding the means of rectifying the error . The contractor shall propose a method ofovercoming the error to the satisfaction of the Engineer

Forcible corrections to piles shall not be made.


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6.0 RECORDS

The Contractor shall keep full records of each pile for daily submission and approval of theEngineer. An approved format for these records will be agreed before commencement of thepiling works.

7.0 PILE LENGTH

All piles shall be founded at a common level and any significant variations are to benotified to the Engineer before proceeding.

8.0 CUT-OFF

All piles shall be terminated in faultless concrete at the cut-off level specified on thedrawings, with a deviation of +200 mm -0.00 mm. The Contractor will be responsible forany additional cost in cutting down or making up piles outside this tolerance or for replacingdefective concrete up to cut-off level.

9.0 CONCRETE

Concrete and reinforcement for piles shall fully comply with the requirements of theappropriate section of this specification together with the following extra clauses. Theminimum cement content for piles to be 400 kg/cu.m with a maximum 0.45 w/c ratio.

Concrete shall be placed in the piles using an approved tremie system. Where piles areconcerted in water or bentonite mud a tremie pipe must be used.

All piles shall contain a minimum of 6 number longitudinal bars with suitable helical binding.The bars are to project a minimum of 1.0 m, as specified on the approved drawings, above thespecified cut-off level. The actual quality and size of the reinforcement bars is to be specifiedby the Contractor and is to be dependent upon the loading conditions on the pile shaft.

10.0 PILING

The Contractor shall supply full details when tendering of the type and size of pile offered,the standards of control to be used and how the calculation and checking of the load bearingcapacity and settlement of the piles will be carried out.

The Contractor shall supply for approval all relevant details of the method of piling andthe proposed plant to be used. Any alternative designs to that shown on the tenderdrawings may be submitted at tender for the Engineer's consideration and approval.

10.1. Reinforced Bored Cast in-situ Piles

Bored piles shall be formed by boring in an approved method to a minimum of 1 meter or twodiameters (whichever is the greater) into a suitable foundation stratum as defined by the Siteinvestigation report and approved by the Engineer. Throughout boring, the hole will be fullylined with a steel casing to ensure whole stability and avoid loss of or loosening of groundbetween piles. Where requested by the Engineer any cores recovered, arisings from boringwill be laid out for examination.

On completion of boring, the pile base shall be thoroughly cleaned of all slurry and loosematerial in a manner to be approved by-the Engineer. The reinforcement cage will then be.placed with appropriate spacers to ensure that a minimum steel cover of 70 mm (or other


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cover as directed) is maintained throughout the pile. Concrete will be placed by tremie pipeto the base of the hole and the tremie will be withdrawn so that its base is never less than 1meter below the top of the concrete until concreting is completed.

Lining casings may be withdrawn on completion of concreting or during concreting providedthat its base is never less than 1 meter below the top of the concrete. Delays between addingindividual batches of concrete to the pile shall not be greater than 15 minutes.

The Contractor shall ensure that when all piles are trimmed back to sound anduncontaminated concrete, the trimmed level shall not be below the specified finished cut-off level as shown on the Engineer's drawings.

10.2. Reinforced Bored Piles by Continuous Flight Auger Method

The construction of piles by the CFA method may only be adopted by prior agreement withthe engineer. This method may only be used on low rise projects.

During uncased boring with continuous flight auger , the feed forward and speed (revolutionsper minute) are to be adjusted according to the soil conditions in a way that the excavation ofsoil will be limited to a quantity that the lateral support of the uncased borehole wall will beensured . While withdrawing the CF-auger, the auger has to be rotated in the same direction asduring drilling into the soil or has to be withdrawn without rotation

The number of auger rotations has to be automatically recorded in dependence to the depth.The records are to be part of the complete pile records.

The system and equipment used must ensure that neither water nor soil can enter the hollowstem of the CF -auger during drilling.

The inclination of piles should not exceed 6 degrees (10:1)

The installation of the reinforcement cage after concreting may be achieved by vibration.Concrete cover and location of the reinforcement cage should be assured. The reinforcementcage should be installed immediately after pouring concrete. The volume of concrete pouredmust be checked to ensure that it is equal to the excavated volume to be occupied by the pile.In the event of significant discrepancies in these two values the matter must be investigated toestablish the cause and necessary action immediately taken. In all events Al-Ain Municipalitymust be informed and approval of corrective measures must be obtained prior to effectingrepairs and alterations.

10.3. Reinforced Cast in situ and Precast Driven Piles

These types of pile may only be used with the prior agreement of the engineer and themunicipality. This agreement will only be given in very particular circumstances.

11.0 PILE TESTS

A minimum of two non working piles shall be installed and tested to a maximum capacity of2.5 times the working load .

Working piles shall be tested to 1.5 times the working load.

The selection of the working load test piles shall be made by the Engineer and theMunicipality Engineers.


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Pile testing procedures shall be in accordance with BS 8004 and to Annexure 3 of the AbuDhabi Municipality Building Regulations and Guidelines for Structural Design.

12.0 INTEGRITY TESTS

All piles shall be integrity tested.

13.0 DRILLING FLUID

Bentonite as supplied to the site and prior to mixing shall be in accordance with specificationDFCP 4 of the Oil Companies Materials Association.

A certificate shall be obtained by the Contractor from the manufacturer of the bentonitepowder, showing the properties of each consignment delivered to the site. This certificateshall be made available to the Engineer on request. The properties to be given by themanufacturer are the apparent viscosity range (in centipoises) and the gel strength range (innewtons per square meter) for solids in water.

Bentonite shall be mixed thoroughly with clean fresh water to make a Suspension which willmaintain the suitability of the pile excavation for the period necessary to place the waterused in mixing the bentonite suspension and of the suspension when supplied to theborehole, shall be not lower that 5( C

Where saline or chemically contaminated groundwater occurs, special precautions shall betaken to modify the bentonite suspension or prehydrate the bentonite in fresh water so as torender it suitable in all respects for the construction of piles.

The frequency of testing drilling fluid and the method and procedure of sampling shall beproposed by the Contractor prior to the commencement of the work. The frequency maysubsequently be varied as required, depending on the consistency of the results obtained.

Control tests shall be carried out on the bentonite suspension, using suitable apparatus.The density of freshly mixed bentonite suspension shall be measured daily as a check on thequality of the suspension being formed. The measuring device shall be calibrated to read towithin 0.005 g/ml. Tests to determine density, viscosity , shear strength and pH value shallbe applied to bentonite supplied to the pile boring. For average soil conditions the resultsshall generally be within the ranges stated in Table 1.

The tests shall be carried out until a consistent working pattern has been established,account being taken of the mixing process, any blending of freshly mixed bentonitesuspension and previously used bentonite suspension and any process which may be usedto remove impurities from previously used bentonite suspension. When the results showconsistent behaviour, the tests for shear strength and pH value may be discontinued, and test todetermine density and viscosity shall be carried out as agreed with the Engineer.

In the event of a change in the established working pattern, tests for shear strength andpH value shall be reintroduced for a period if required.


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Table 1

Property to be measured Range of results at 20' C Test method

Density

Viscosity

Shear strength(10 minute gel strength)

pH

Less than 1.10g/ml

30 - 90 s or less than 20 Cp

1.4 - 10 N/m2or4-40 N/m2

9.5 - 12

Mud density balance

Marsh cone method Fannviscometer *

Shear meter

Fann viscorneter

pH indicatorpaper strips or electrical pHmeter

* Where the Fann viscometer is specified, the fluid sample should be screened by anumber 52 sieve (300 mu) prior to testing.

END OF SECTION


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Section BB. Concrete Works


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2. CONCRETE WORKS

2.1. Concrete

2.1.1. Codes of Practice

2.1.2. Materials

2.1.3. Storage of Materials

2.1.4. Testing of Materials

2.1.5. Concrete Mix Design & Concrete Mixing

2.1.6. Sampling & Testing of Concrete

2.1.7. Quality Control of Concrete

2.1.8. Concrete Placing

2.1.9. Vibration

2.1.10. Cutting Away

2.1.11. Waterproof Concrete

2.1.12. Expansion Joints

2.1.13. Form-work

2.1.14. Construction Joints

2.1.15. Remedial Treatment of Surfaces

2.1.16. Finishes

2.1.17. Curing

2.1.18. Work below ground

2.2. Glass Reinforced Plastic (GRP)

2.3. Glass Reinforced Concrete (GRC)


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2. CONCRETE WORKS

2.1. CONCRETE

2.1.1. CODES OF PRACTICE

All Materials shall be of the best quality and to the approval of the Engineer in accordanceto the relevant standards such as ASTM, British Standards, ACI, IBC-UPC and AgreementBoard Certificates noted in Specifications and the Local Authorities the ESTIDAMACredits Requirements to be fulfilled for obtaining the required Pearl Ratings for the Project.


2.1.2. MATERIALS

Except where otherwise specified all materials for which British Standard Specificationsexist shall conform to the latest revised editions of such specifications as published at thedate of tender.

a) Cement

Except where otherwise required, cement shall be locally manufactured controlled finenessordinary Portland cement complying with BS 12 or ASTM C 150 Type 1.

The source of supply of cement shall be subject to the Engineer's approval and theContractor shall at all times furnish the manufacturer's certificates and proof that therequired specification has been complied with together with a note of the date ofmanufacturer, certified by an independent agency. The Engineer shall have the power toreject a part of the whole of any consignment of cement if the considers it to be unsuitablefor use in the works.

The chemical composition of the cement shall comply with the standards as stipulated abovean in addition with the following requirements.

i. Tricalcium Aliminate (C3A) content shall be within the range of 4% to 12%.

ii. The total lime (CaO) contents shall not exceed 70% unless agreed otherwise by theEngineer.

iii. The total alkali content shall not exceed 0.6%.

One brand as approved by the Engineer shall be used throughout the works unless otherwiseauthorized by the Engineer in writing.

b) Aggregates for Concrete

i. General

Aggregates for concrete shall consist of naturally occurring materials complying with therequirements of fine and coarse aggregates of BS 882 and as specified herein, except that forClass D concrete all-in aggregate within the grading limits of Table 3 of BS 882 may beused. Approval of aggregate will not prevent subsequent rejection if results of subsequenttests of not indicate compliance with the specified requirements. The properties specified foraggregates in below points Nos. ii, iii & IV shall be for aggregates form individual sources.The use of beach sand in mixes for reinforced concrete is prohibited. The frequency oftesting aggregates shall be one test each 50 m or different batch of aggregates received at


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site. The CI test shall be as per BS 812 (Part 117), S03 as per BS 812 (118) and waterabsorption test as per BS 812.

ii. Fine Aggregate

The grading of fine aggregate shall be within the limits of Class C or M, table 5 BS 882 :1983 and the percentage by weight passing BS 410 test sieve 300 m shall not be in excess of30%.

The amount of deleterious material shall not exceed the following limits when determinedby the ASTM standard test stated below.

Clay Lumps & friable particles 1% by weight ASTM C142Coal, Lignite & shells 1% by weight ASTM C123

Fine aggregate shall satisfy the requirements of ASTM C33 with regard to organicimpurities, when tested in accordance with ASTM C40 and C87. Local sands containaggressive salts, and it is essential to test the fine aggregate to ascertain that the maximumquantity of acid soluble chlorides shall not exceed 0.06% by weight of fine aggregate andthe maximum quantity of acid soluble sulphate shall not exceed 0.4% by weight of fineaggregate. The fine aggregates shall be washed with fresh water complying with BS 3148(1980) Unwashed sand shall not be allowed under any circumstances for any part of theworks.

When fine aggregate is subjected to five cycles of the sodium Sulphate Soundness Test.ASTM C88, the loss shall not exceed 10% of weight.

Fine aggregate shall be of such uniformity that the fineness modulus as defined in AASHTOM6 shall not vary more than 0.20 either way from finess modulus of the representativesamples used in the mix design.

The sand equivalent for fine aggregate (AASHTO T176) shall be a minimum of 70%.

The water absorption of fine aggregate shall not exceed 2% (BS 812)

iii. Coarse Aggregate

Coarse Aggregate shall be prepared as single size aggregate and blended to produce normalsize grading. The combined grading of coarse aggregate shall be within the limits given inTable 1 of BS 882 for nominal size of graded aggregate 20mm to 5mm.

The proportion of soft and friable particles in coarse aggregate shall not exceed 1% whentested in accordance with ASTM C142. The maximum quantity of acid soluble chlorides(C1) shall not exceed 0.03% weight of coarse aggregate. The maximum quantity of acidsoluble sulphate (SO3) shall not exceed 0.4% by weight of coarse aggregate. (BS 812 part118). No organic matter of any nature shall be permissible to be contained by the aggregatessuch as wood, paper, plastic, or any other matter. The standard test method for organicmatters shall be as per BS 1377 Test 8.

iv. Combined Aggregate in Concrete

For the combined grading, the quantities of acid soluble salts shall not exceed the followingin the concrete mix.

Chlorides (CI) - Max. 0.3% by weight of cement (OPC) and max 0.06% for SRCSulphates (So3) - Max 4% by weight of cement (including the sulphate in the cement)


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v. Potential Aggregate-Cement Reactivity

If so directed by the Engineer, the Contractor shall carry out petrographic analysis inaccordance with ASTM 33 and C295 on all aggregates proposed for use. Arising from suchanalysis the Engineer may require the Contractor to perform further tests in accordance withASTM C286 and BRE Digest No. 35; also in accordance with ASTM C227 and C586 if theEngineer so decides after his examination of the results of the proceeding tests. In the eventthat tests in accordance with ASTM C227 are called for, the cement used in the test shallhave an alkali content (expressed as sodium oxide + 0.658 potassium oxide) greater than0.8% by weight of 2.25 to 1.0. Depending on the results obtained the Engineer may decideto limit the alkali content (Na20 and K20) of the cement to 0.6%.

c) Water

Unless otherwise authorized in writing by the engineer only water form portable supplysystem may be used for mixing concrete and other products containing cement. Similarlyonly portable water conforming to BS 3148 (1980) may be used for curing purposes. Noother source of water shall be allowed to be used for any of the above purposes.The PH requirements of water shall be from 7 - 9.The inorganic impurities in water shall not exceed the following:

Chlorides = 600mg/litersSulphates = 500mg/litersTotal dissolved solids = 2000mg/litersAlkali Carbonate and Bicarbonate = 1000mg/liters

d) Admixtures

No admixture of any type shall be allowed in preparation of concrete unless agreed by theEngineer in writing. In case any admixture are used these should be silicates based (sodiumor calcium or magnesium) pore blocking type to produce water proof, impervious and denseconcrete. The admixture shall be generally to ASTM-C-260 + C494 standards. The ratesand method of application shall be as instructed by the manufacturer. Admixture containingchlorides salts will not be permitted under any circumstances.

e) Reinforcement for Concrete

Steel reinforcement shall generally be one of the following types:

i. Hot rolled mild, medium or high yield steel smooth round or deformed bars complyingwith BS 4449 or similar approved standard.

ii. Cold twisted bars complying with BS 4482 or similar approved standard.

iii. Steel fabric reinforcement complying with BS 4483 or similar approved standard.

In case any other type of reinforcement is required, it shall comply with the requirements ofthe particular specification.

All reinforcement shall be free of loose rust and mill scale and any coating such as oil, clay,paint etc., which might impair the bond with the concrete. Steel reinforcement shall bestored in clean conditions and shall be protected from damage at all times. It shall be cleanand free of loose rust, dirt, mud, loose mill scale, paint, oil or all other foreign substances atthe time of fixing in position and subsequent concreting.

Manufacturer's test certificates for all classes of reinforcement shall be supplied whenrequired. Specimens sufficient for three tensile tests and three cold bending tests per tentons of bars or fraction thereof and for each different size of bar shall be sampled under the


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supervision of the Architect. Testing shall be in accordance with BS 4449 or other approvedstandard and batches shall be rejected if the average results for each batch are not inaccordance with the specification.

The Contractor shall cut and bend bars to BS 4466 (or ACI (SP-66)) and to schedule, ifprovided or unless otherwise instructed by the Architect. Straight sections of bars must bekept out of winding. The internal radius of bends shall in no case be less than two times thediameter of the bar. Great care is to be taken to bend stirrups and blinders separately and tothe sizes shown.

All bars will be bent cold on approved machines, and at temperatures in the range of 5C to100C. Lengthening of bars by welding, and rebending of incorrectly bent bars will not bepermitted, except where requested by the Engineer.

Unless otherwise allowed for in the particular specification splices in reinforcing bars shallbe formed by lapping. Such laps in bars in any member shall be staggered. Except asotherwise indicated on the drawings, the minimum overlap of lapped splices shall be 40 bardiameters or 300mm whichever is greater. No splices shall be made in the reinforcementexcept where described in the Contract or where approved by the Engineer.

Reinforcement shall be placed and maintained in the position shown in the Contract. Unlessotherwise permitted by the Engineer, all bar intersections shall be tied together and the endsof the tying wire shall be turned into the main body of the concrete. 1.2mm diameterstainless steel wire shall be used throughout.

f) Cover Blocks (Buried Concrete Surfaces)

i. Concrete cover blocks required for ensuring that the reinforcement is correctly positioned,shall be as small as possible consistent with their purpose, of a shape acceptable to theEngineer, and designed so that they will not overturn when the concrete is placed. Theyshall be made of concrete with 10mm maximum aggregate size to produce the samestrength as the adjacent concrete. Tying wire complying with the requirements of abovetopic e last paragraph shall be cast in the block for the purpose of tying it to thereinforcement.

ii.Cover Blocks (Exposed Concrete Surfaces)Concrete cover blocks required for ensuring that the reinforcement is correctly positioned,shall be as small as possible consistent with their purpose, of a shape acceptable to theEngineer, and designed so that they will not overturn when the concrete is placed. Theyshall be made of asbestos cement, factory produced and of the same strength as theadjacent concrete. Tying wire complying with the requirements of above topic e lastparagraph shall be cast in the block for the purpose of tying it to the reinforcement.

2.1.3. STORAGE OF MATERIALS

a) Cement

The cement shall be stored in a weather proof shed used exclusively for this purpose. Theshed shall be large enough to allow proper aeration and effectual separation of the variousconsignments, the old consignments being used before the latter ones. Cement shall not bestored on site for more than 21 days; after this it must be removed from the site at theContractor's expense. Alternatively, the cement may be stored in a Silo, the design of whichhas been approved by the Engineer.

All cement received shall be subjected to test at a frequency of one test each 50m or atchange of source of supply.


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b) Aggregates

The aggregates are to be stored on a concrete slab in such a way that contamination fromother materials and inter-mixing of the various grading will be prevented. The aggregateshall be deposited in a way that will prevent segregation through dropping on to the peak ofa high heap.

The Contractor's attention is drawn to the fact that for some of the design mixes specified itmay be necessary in order to obtain the required cube strength with minimum cementcontent to store the aggregate in different sizes so that they can be combined in the correctproportion at the mixer.

c) Reinforcement

The reinforcement should be stored clear of the ground and should be protected fromcontamination by other materials.

2.1.4. TESTING OF MATERIALS

(All tests to be carried out by an independent approved Lab.)

The costs of all tests required under this clause are to be met by the Contractor, whether thetest results show the materials to be satisfactory for the work or not.

The Contractor shall submit to the Engineer sufficient quantity of material proposed to beused for the works, together with a list of suppliers to be employed. The Engineer's consentin wiring shall be obtained to all such samples and source of supply before any concretingwork is put in hand and no change shall subsequently be made without the Engineer'sapproval. The Engineer shall have access to all sources of supply for the purpose ofinspecting and taking samples of any materials which will be later delivered to the site.

a) Cement

Cement will be tested at an approved testing station. Samples are to be taken from eachdelivery of cement as directed and conveyed by the Contractor to a testing station to theapproval of the Engineer, or as specified.

b) Aggregate

All aggregates shall be tested by an approved testing laboratory at the beginning of the workand for every 50m of aggregate or before any change is made in the source of supply duringthe progress of the work and the Engineer shall have approved the results of such testsbefore the preliminary test cubes are made.

The size of the sample shall be as required by the testing laboratory but in the absence ofspecific instruction two samples of not less than 12 kg. of fine aggregate and 50 kg. ofcoarse aggregate shall be quartered down from representative bulk samples for each test.Each sample shall clearly and durably labeled to give the name of the supplier and of the pitof quarry and one of each pair of samples shall be sent to the laboratory for testing and oneretained on the site for reference.

c) Reinforcement

Generally the manufacturer's test certification should be obtained with each delivery ofreinforcement but the Engineer reserves the right to request tests from an independenttesting station from time to time or from every batch of steel delivered to site.


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d) Testing Equipment

The Contractor shall provide:-

1) Sufficient 150mm. cast iron cube moulds to enable him to carry out the requirementsof this specification.

2) BS Slump Cone, base plate and tamping rod.

3) Maximum and minimum thermometers, also thermometer to measure temperature ofconcrete.

4) Suitable graduated measuring tubes for measuring the moisture content of fineaggregate.

5) Suitable weighing scales

2.1.5. CONCRETE MIX DESIGN & CONCRETE MIXING

a) The concrete to be used in each part of the works shall be of the class described in thedrawing and shall conform to the requirements of the grade as set out in the table, unlessotherwise specified.

Mix for structural concrete shall be designed by the Ready-mix Sub-contractor. The grade ofconcrete shall be as shown on the drawings and as denoted by the minimum 28 day workscube strength and the maximum size of aggregate. Cement for blinding and mass concretebelow ground level shall be sulphate resisting. Cement for reinforced concrete shall beordinary Portland cement, unless otherwise specified or approved by Engineer on the basisof Soil Investigation Report or any other related information.

b)

For pump able concrete, plasticizers / Super-plasticizer may be used in particular cases toincrease the work-ability. As there is likelihood of higher strengths due to their use, therequirements of average of four cubes and that of an individual test result have to becorrespondingly increased and those figures shall be agreed upon at the trial mix stage.

7-day strength is 0.8 of 28 days strength.

Grade of Concrete A B C D E F

Characteristic Strength 28 daysN/mm2 40 35 25 15 60 45

Mixes to be designed for a meanstrength (N/mm) 45 40 30 20 68 52

Slump Max (with Plasticizer orSuper-plasticizer 100 100 100 120 120 100

Max water cement ratio 0.4 0.45 0.55 0.65 0.35 0.38

Minimum Cement (kg/m) 400 370 300 250 450 420

Nominal Maximum Size ofaggregate 20mm 20mm 20mm 20mm 20mm 20mm


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All materials are to generally conform to following standards:-

Cement : B.S 12Water : B.S 3148 (Also as specified for concrete works)Aggregates : B.S 882Admixtures : B.S 5075 Part I

All concrete mixes are to be designed according to requirements of the above table.

The concrete shall be mixed by machine to a uniform colour and consistency before placing.The quantity of water used shall not exceed that required to produce a concrete withsufficient work ability to be placed and compacted in the required location.

The concrete shall be compacted by mechanical vibration.

c) Trial Mixes

No structural concrete shall be placed in the works until the relevant mix has been approvedby the Engineer.

Generally for the major concrete only an approved ready-mix supply is to be used.

For minor concreting sections site mix will be accepted but must comply with thisspecification. The Contractor shall, at least 35 days before the commencement of concreting,have trial mixes prepared in a laboratory to be approved by the Engineer. The concrete fromeach mix shall be tested in accordance with Clause 4.1.6 and must satisfy the strengthrequirements of Clause 4.1.5.

When the mix has been approved, no variations shall be made in the proportions, theoriginal source of the cement and aggregates, or in the type, size and grading zone of thelatter without the consent of the Engineer who may require further tests to be made.

The Engineer may also require practical tests to be made on the site by filling trial moulds toconfirm the suitability of the mix for the works. In these tests, the type of plant used formixing, the method of compaction used, and the form-work face to the mould shall besimilar in all respects to those intended for use in the works.

When the Contractor intends to purchase factory-made precast concrete units, the Engineermay dispense with trial mixes and laboratory tests, provided that evidence is given whichsatisfies him that the factory regularly produces concrete which complies with theSpecification. The evidence shall include details of mix proportions, water-cement ratio,work-ability and strengths obtained at 7 and 28 days.

d) Mixing Concrete (for minor elements)

i. The weighing and water-dispensing mechanisms shall be maintained in good order. Theiraccuracy shall be maintained within the tolerances described in BS 1305 and checkedagainst accurate weights and volumes when required by the Engineer.

ii. The mass of cement and each size of aggregate indicated by the mechanisms employedshall be within a tolerance of 28% of the respective mass per batch agreed by the Engineer.The mass of the fine and coarse aggregates shall be adjusted to allow for the free watercontained in them. The water to be added to the mix shall be reduced by the quantity of freewater contained in the fine coarse aggregates, which shall be determined by the Contractorby a method approved by the Engineer immediately before mixing begins and further as theEngineer requires.


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iii. Unless otherwise agreed by the Engineer, concrete shall be mixed in a batch type mixermanufactured in accordance with BS 1305 or in a batch type mixer, a specimen of whichhas been tested in accordance with BS 3963 and having a mixing performance within thelimits of Table 6 of BS 1305. Where appropriate the batch capacity, conform to the detailsfurnished in accordance with the requirements of BS 3963 for the mix which correspondsmost closely to the mix proportions being used. The mixing blades of pan mixers shall bemaintained within the tolerances specified by the manufacturer of the mixer and the bladesshall be replaced when it is no longer possible to maintain the tolerances by adjustment.

iv. Mixers which have been out of use for more than 30 minutes shall be thoroughly cleanedbefore any fresh concrete is mixed, and unless otherwise agreed by the Engineer, the nextbatch of concrete through the mixer shall contain only two-thirds of the normal quantity ofcoarse aggregate. Mixing plant shall be thoroughly cleaned before changing from one typeof cement to another.

v. The Contractor shall ensure that the constituent materials of the concrete are sufficientlycool to prevent the concrete from stiffening in the interval between its discharge from themixer and compaction in its final position.

e) Ready-Mixed Concrete (for all major concrete pours and elements)

i. Ready-mixed concrete as defined in BS 5238, batched off the site, is to be used for theworks but must comply with all requirements of the Contract.

ii. The concrete shall be carried in purpose-made agitations, operating continuously, or truckmixers. The concrete shall be compacted and in its final position within 2 hours of theintroduction of cement to the aggregates, unless a longer time is agreed by the Engineer.The time of such introduction shall be recorded on the delivery note together with the rightof the constituents of each mix.

iii. When truck-mixed concrete is used, water shall be added under supervision at the centralbatching plant but in no circumstances shall water be added in transit or at site.

iv. Unless otherwise agreed by the Engineer, truck mixer units and their mixing and dischargeperformance shall comply with the requirements of BS 4251. Mixing shall continue for thenumber and rate of revolutions recommended in accordance with Item 9 in Appendix B ofBS 4251 or, in the absence of the manufacturer's instructions, mixing shall continue for notless than 100 revolutions at a rate of not less than 7 revolutions per minute.

f) Precautions Against High Temperatures

When the rate of evaporation of surface moisture from concrete is expected to approach 1kg/m per hour or when the shade air temperature is 35C and rising, precautions shall betaken, including the following:

Fig.1108 - effect of concrete and air temperatures, relative humidity, and wind velocity onthe rate of evaporation of surface moisture from concrete.

1) Dampening the forms.

2) Reducing the concrete temperature to the lowest practical level by procedures such as:


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i. shading the aggregateii. cooling the mixing water before use and/or adding flaked ice.iii. screening the mixing plant and transporting vehicles from wind, rain and sun.iv. erecting wind breaks ad sunshades at the concrete placing locationv. reducing the time between the placing of the concrete and the start of curing to the

minimum possible.vi. minimizing evaporation (particularly during the first few hours subsequent to

placing the concrete) by suitable means such as applying moisture by fog spraying.

All precautions to be taken shall be subject to the Engineer's approval and the Contractorshall demonstrate that all approved precautions are available for use prior to the Engineergranting approval to any concreting operation.

The temperature of the concrete when placed shall not exceed 32C or shall be concretemixed or placed when the shade air temperature is 40C or above, or is expected to reachsuch a level during concreting, without special permission from the Engineer.

g) Supervision of Concrete Work

The Contractor is to employ a qualified competent person whose main duty is to superviseall stages in the preparation and placing of the concrete work.

Concrete Mixes - See Engineers Drawing "General Notes" which shall supersede thespecified mix in the general specifications, if so instructed by the Engineer.

2.1.6. SAMPLING & TESTING OF CONCRETE

a) General

The cost, including transport to the testing station of all cube tests required under thisspecification, it to be met by the Contractor, whether the test results are satisfactory or not.The Contractor shall keep a set of at least six cube molds on site at all times, together with astandard slump cone.

b) Sampling

Sampling shall be in accordance with the requirements of BS 1881 (method of TestingConcrete) at a testing station approved by the Engineer.

Concrete shall be sampled in two series as follows:

Series A - one batch shall be sampled at random from every 50 cu.m of concrete placed. Forstrength tests one sample shall be taken from each batch samples, from which six test cubesshall be made, three of which shall be tested at 7 days and three at 28 days.

Series B - batches shall be sampled at the direction of the Engineer. For strength tests threeindependent samples shall be taken from each batch to be sampled, from each of which onetest cube shall be made. Test cbes shall test at 7 days as directed.

The work-ability tests, one sample shall be taken at an early stage the discharge of eachbatch sampled at the direction of the Engineer.


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c) Testing

Test cubes shall be made, cured and tested in accordance with BS 1881 Parts 101,108,111 &116.

Where a batch has been sampled for the purpose of determining the workability of theconcrete, one test shall be made on each sample using one of the following tests inaccordance with BS 1881 (1983) and shall be within the following limits of the values forthe accepted trial mix:

Slump 25mm or 1/3 of the trial mix value whichever is the greater.

Compacting Factor 0.03

`V-B' Consistometer 3 seconds or 15% of the average time for the trial mixwhichever is the greater.

d) Load Tests

Tests loads shall generally be in accordance with relevant clauses of CP-110-1972, or insuch other manner as may be directed by the Engineer.

e) Records

Each cube shall be clearly marked showing from which part of the structure the concretewas obtained and the mix proportions used, and this information must be recorded on thereport sheet. An accurate record is to be kept on site of all test made, indemnifying them tothe various parts of the work.

f) Work not upto standard

If any of the works tests are not upto standard, the Engineer shall be entitled t stop the workuntil the reason has been investigated and steps taken to prevent further low results.

Any concrete carried out from a batch that afterward appears to be faulty will be liable torejection and, if so directed, the Contractor shall, at his own expense, cut and replace thedefective work, or take such other measures as may be allowed to prove by means of testloading, at his own expense, that the concrete is capable of safely withstanding theprescribed stresses.

2.1.7. QUALITY CONTROL OF CONCRETE

a) General

The control of concrete quality shall satisfy the requirements of Clause 4.1.5 (a to c).

b) Standard of Control

The Standard of control for structural concrete shall be such that not more than 5% of worksconcrete test cubes shall have strengths which fall below the appropriate specified minimumstrength. Compliance with this standard of control shall be monitored by the methodsdescribed below.

As test results become available average values of test results and values of standarddeviation shall be determined on a continuing basis for Series A cubes taking 7 days and 28days tests results separately, but in each calculating the Standard deviation.


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Until the relationship between 7 days strength and 28 days strength has been established tothe satisfaction of the Engineer, the assessment of control shall be based on the 28 day testsonly. The required standard of control shall be deemed to have been attained if the averagevalue of the 28 day test results exceeds the specified minimum strength as detailed on thedrawing by not less than 1.64 times the standard deviation or by 7.5N/mm for Grades C andabove or by 5N/mm for Grade D, whichever is the greater. Where less than 40 tests resultsare available for the calculation of the standard deviation, the average of the 28 days testshall exceed the specified minimum strength, by 15N/mm for Grades C and above or10N/mm for Grade D.

When the Engineer is satisfied that sufficient cube test results from Series A cubes areavailable to establish the rates of 7 days to 28 days strengths the assessment of control asdescribed in paragraph above shall also be based on the 7 days cube tests.

c) Series B Test Cubes

The strength requirements of each set of three test cubes of Series B shall be deemed to besatisfied if none of the test results for the three cubes is below the required minimumstrength, or if the average value of test results for the three cubes is not less than the requiredminimum strength and the difference between the greatest and the lowest value is notgreater than 20% of the average value. The required minimum strength shall be the specifiedminimum strength at 28 days, as detailed on the drawing, multiplied by that ratio of 7 daysand 28 days strength as determined.

In cases where the standard of control is being met but where anyone cube tested has astrength less than 85% of the required minimum strength, or where any set of three cubes inSeries B fails to satisfy the strength requirements as specified, the Contractor shall take suchremedial action as the Engineer may direct. This may require the cutting out of the concreteto which the cubes correspond together with any sound concrete as the Engineer mayconsider necessary in order to effect a satisfactory repair, the whole to be carried out at theContractor's expense.

d) Additional Tests

Where a subsequent operation is dependent on the strength of the concrete in particularportions of the work, for example if the Contractor wishes to remove form-work in advanceof the minimum periods stated or to subject the concrete to early loading, the Engineer willrequire additional cubes to be made, stored, cured and tested on the same basis as isspecified for Series A & B in Clause 4.6 (b&c) to check the concrete has attained sufficientstrength for the subsequent operation to proceed until he is satisfied that the requisitestrength has been reached.

2.1.8. CONCRETE PLACING

Before the concrete is actually placed in position the inside of the shuttering or mouldsshould be inspected by the Engineer or the Engineer's representative to see that it has beenproperly assembled and fixed.

The Contractor shall submit to the Engineer a weekly and a monthly concreting program,which shall be approved before the concreting work is executed.

The Contractor shall be responsible for giving 24 hours notice in writing to enable theEngineer to have a representative present during concreting. In the event of the Contractornot giving such notice, the Engineer reserves the right to cut away such concrete as he mayrequire to expose the reinforcement and the cost of such cutting away shall be borne by theContractor, even is the position of the reinforcement is found to be correct.


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As soon as possible after the mixing and before the initial set has taken place, the concreteshall be deposited directly in the work from barrows, etc. carefully trimmed into position inlayers and well rammed and vibrated. Concrete shall not be thrown or dropped from aheight exceeding 2m without the written authority of the Engineer.

The concrete shall be worked up against the face of the previously deposited concrete oragainst form-work or molds with rods or long tampers. Very great importance is attached tothe depositing and through consolidating of the concrete to ensure that it is homogenous andfree from interstices and that it is in contact throughout with the forms or molds; all to theentire satisfaction of the Engineer.

Care shall be taken not to disturb setting concrete by shocks, loading or otherwise before ithas sufficiently hardened. Any concrete that it not finally placed within half an hour ofmixing shall be discarded. Any concrete which shows signs of initial setting before it isdeposited in the forms or molds shall not be used in the work and shall be removed from thesite or otherwise disposed of to the satisfaction of the Engineer.

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VOLUME 1 - Civil & Architectural Specifications

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Transcript of VOLUME 1 - Civil & Architectural Specifications