ANNEXURE - II TECHNICAL SPECIFICATIONS 1 TECHNICAL SPECIFICATIONS FOR CIVIL WORKS SECTION A – GENERAL The specifications herein are intended for the general descriptions of the work, quality and workmanship. The specification are not, however, intended to cover the minute details, and the work shall be executed according to the specifications given herein or in its absence the relevant CPWD Specification, or the best practice recommended by reputed manufacturers, or the best Public Works Department practices or to the recommendations of relevant Indian Standard/International Practice or according to the instructions of the Engineer-in- Charge. The project is registered with GRIHA for Green Building rating of 4/5 star, the provision stipulated is GRIHA Manual, will over ride the provisions stipulated in case of any difference. Wherever reference to CPWD/Indian Standard Code / NBC and practices is made, they shall be referred to the latest edition/revision of the same. The tenderer is expected to get clarified any doubts about the specifications etc. before
Transcript
ANNEXURE - II
TECHNICAL SPECIFICATIONS
1 TECHNICAL SPECIFICATIONS FOR CIVIL WORKS
SECTION A – GENERAL
The specifications herein are intended for the general descriptions of the work, quality and workmanship. The specification are not, however, intended to cover the minute details, and the work shall be executed according to the specifications given herein or in its absence the relevant CPWD Specification, or the best practice recommended by reputed manufacturers, or the best Public Works Department practices or to the recommendations of relevant Indian Standard/International Practice or according to the instructions of the Engineer-in-Charge. The project is registered with GRIHA for Green Building rating of 4/5 star, the provision stipulated is GRIHA Manual, will over ride the provisions stipulated in case of any difference.
Wherever reference to CPWD/Indian Standard Code / NBC and practices is made, they shall be referred to the latest edition/revision of the same. The tenderer is expected to get clarified any doubts about the specifications etc. before submission of the Tender in writing with the The Corporation in respect of interpretation of any portions of these documents.
Sketches relevant to the specifications of waterproofing treatment, expansion joints, brick coba roofing treatments, acoustic treatment etc. are enclosed herein and they shall be read in conjunction with the specifications and item descriptions as given in BOQ.
All testing shall be to the best standards offered in the respective specialists’ tradepractice. Detailed shop drawings compatible with BOQ items shall be prepared and gotapproved. Mock-ups if necessary shall be prepared and submitted along with site visits to similar installations to facilitate proper monitoring of execution to the best standards.Tenderers to consider all the above and quote their rates accordingly.
The tenderer shall provide a performance guarantee of requisite value to be indicated inthe Bill of quantities/Specifications, to provide for expenses, to cover the risk and cost ofrectification of defect, noticed during guarantee period. Guarantee period to start fromthe date of completion of the project. Such performance guarantees shall be provided for anti-termite treatment, waterproofing works and all other works as specified in the tender. The rates quoted by the bidder shall be deemed to include the cost of all suchperformance guarantees.
SECTION B - : MATERIALS
All materials shall be procured and arranged by contractor after approval by the EIC to its quality and specifications as of tender. Tests for materials shall be carried out by contractor as directed by EIC and costs of all such test shall be borne by contractor. A site laboratory shall be made available by the contractor, which shall have the following :
1. Cube testing machine (hydraulic) with cube moulds2. Dumpy level/ Auto level3. Theodolite/Total Station4. Vernier caliper5. Screw gauge6. Full set of sieves (for fine aggregate)7. Full set of sieves (for coarse aggregate)8. Slump cone apparatus9. Weigh balance (5/20 kg.)10. Sand bulkage apparatus11. Equipments for testing of cement12. All other equipments/instruments/apparatus as instructed by EIC.13. Rebound Hammer
Contractor shall procure sufficient quantities of materials of approved quality, well inadvance to ensure completion in stipulated time. In case material not available locally, the Contractor shall arrange from areas with longer leads and shall not be paid any extra on this account. Also this shall not be considered for granting any extension of time.
1. Materials shall be of the best approved quality and they shall comply with therespective Indian Standard specifications.
2. Samples of all materials shall be got approved before placing order and the approvedsample shall be deposited with the Architect.
3. In case of non-availability of materials in metric sizes, the nearest size in FPS unitsshall be provided with the prior approval of the Architects / EIC for which neither
extra will be paid nor any rebate shall be recovered.
4. If directed, materials shall be tested in any approved Testing Laboratory and the testcertificate in original shall be submitted to the Architects and the entire chargesconnected with testing including charges for repeated tests and transportation ifordered, shall be borne by the Contractor.
5. It shall be obligatory for the Contractor to furnish certificate, if demanded by theArchitects, from manufacturer or the material supplier, that the work has been carriedout by using their material and as per their material specifications.
6. All materials supplied by the employer/any other specialist firms shall be properlystored and the Contractor shall be responsible for its safe custody until they arerequired on the works and till the completion of work.
7. Unless otherwise shown in the Drawings or mentioned in the Schedule of Quantities or Special Specifications, the quality of materials, workmanship dimensions etc. shall be as specified .
8. All equipment and facilities for carrying out field test and materials shall be providedby the Contractors without any extra cost.
(a) CEMENT :
OPC Cement shall comply in every respect with the requirements of the latestpublication of IS : 269 for 33 grade OPC cement, IS:8112 for 43 grade OPC,IS:12269for 53 grade OPC .Unless otherwise specified ordinary _alvaniz cement shall be used.Portland pozzolona cement shall conform to IS:1489 (Part-I).
The weight of ordinary _alvaniz cement shall be taken as 1440 kg. Per cu.m. (90 lbs. Per cft) Cement shall be measured by weight and in whole bags, and each undisturbed and sealed 50 kg. bag being considered equivalent to 35 litres (1.2 cft) in volume, care should be taken to see that each bag contains full quantity of cement. When part bag is required cement shall be taken by weight or measured in measuring boxes.
No other make of cement but that approved by the Architects will be allowed on worksand the source of supply shall not be changed without approval of the Architects inwriting. Test certificates to show that cement is fully complying the specifications shallbe submitted to the Architects and notwithstanding this the Architects may at hisdiscretion, order that the cement brought on site and which he may consider damaged or of doubtful quality for any reason whatsoever, shall be retested in an approved testing laboratory and fresh certificates of its soundness shall be produced. Cement ordered for retesting shall not be used for any work pending results of retest.
Cement shall be stored in weather proof sheds with raised wooden plank floor to prevent deterioration by dampness or intrusion of foreign matter. It shall be stored in
such a way as to allow the removal and use of cement in chronological order of receipt i.e. first received being first used. Cement deteriorated and or clotted shall not be used on work but shall be removed at once from the site. However, allowing use of warehouse set cement shall be determined by the Architect.
Weekly record of cement received and consumed shall be maintained by the Contractor in an approved form and submitted to Architects./ E.I.C.
(b) FINE AGGREGATE :
Sand shall conform to IS : 383 and relevant portions of IS : 515. It shall pass through aI.S Sieve 4.75 mm (3/16 B.S.) test sieve, 100% of fine again shall be from natural source or crushed stone screenings, if allowed, chemically inert, clean, sharp, hard, durable, well graded and free from dust, clay, shale, large pebbles, salt, organic matter, loam, mica or other deleterious matter. The sum of percentage of all deleterious materials in sand shall not exceed 5% by weight. It shall be washed if directed to reduce the percentage of deleterious substance to acceptable limits, sand shall not contain any trace of salt and it shall be tested and sand containing any trace of salt shall be rejected.
The fine aggregate for concrete shall be graded within limits as specified in IS : 383 or as described in Clause 3.1.4.3 of CPWD specification.
The fine aggregate shall be stacked carefully on a clean hard dry surface so that it will not get mixed up with deleterious foreign materials. If such a surface is not available aplatform of planks or corrugated iron sheets or brick floor or a thin layer of lean concreteshall be prepared.
The grading of sand (fine approach) for masonry mortar shall conform is IS:2116 and that for plaster shall be as per IS:1542.
(c) COARSE AGGREGATE :
Shall consist of crushed or broken stone 95% of which shall be retained on 4.75 mm IStest Sieve. It shall be obtained from crushing Granite, Quartzite Trap, Basalt or similarapproved stones from approved quarry and shall conform to IS : 383 and IS : 515 Coarse aggregate shall be chemically inert when mixed with cement and shall be cubical in shape and free from sift, friable, thin, porous, laminated or flaky pieces. It shall be free from dust and any other foreign matter.
Gravel/Shingle of desired grading may be permitted as a substitute in part or full in plaincement concrete if the Architect is otherwise satisfied about the quality of aggregate. For all R.C.C work the size of coarse aggregate shall be 20 mm and down guage.
(d) REINFOCEMENT :
All Reinforcement shall be of TMT (Thermomechanically treated) Grade 415D or 500Dconforming to I.S. 1786-2008 unless mentioned otherwise .Mild steel tested qualityconforming to IS : 432 (Part II) Part and any other IS applicable or deformed barconforming to IS : 1786 or hard drawn steel wire fabric conforming to IS : 1566 .All steelshall be TMT of Fe 415 grade unless otherwise specified.In case TMT steel is beingsourced/procured from local rerollers,they must be approved conversion agents ofmainstream suppliers of reinforcement steel Like SAIL,VSL,Tata capable of furnishingtest certificates with each consignment of steel duly endorsed by the principle suppliersi.e SAIL,TATA,VSL etc.as and when required.
All finished bars shall be free from (i) loose mill scales, loose rust and coats of paints, oil, mud or any other substance which may destroy or reduce board cracks, surface flaws, Laminations, Jagged and imperfect edges.Refer Clause 6.1 of CPWD Specification for columns. The reinforcement shall be cleared by sand blasting or any other treatment as may be recommended.
Design Mix Concrete:
1. The contractor shall be guarantor of quality of concrete used in the constructionand shall carry out the mix design and mix so designate (not the method of design) shallbe approved by the Employer within the limitation of parameters laid down by IS:456-2000. Mix Design should be prepared as per IS : 10262.
2.The mix shall be designed to produce the grade of concrete having required workability and a characteristic strength not less than appropriate values of Table-2 to IS:456-2000. The TARGET MEAN STRENGTH OF CONCRETE MIX should be equal to characteristic strength plus 1.65 times the standard deviation.
3.Mix design done earlier not prior to one year may be considered adequate for later work provided there is NO CHANGE in the source and quality of material
4.While using PPC with flyash,every effort should be made to use cement from approved manufacturer containing less than 25% flyash by weight.
Nominal Mix Concrete
1.Nominal Mix Concrete may be used for concrete of M-20 or lower grade. Theproportions of material for nominal mi concrete shall be as per Table 9 of IS:456-2000.
2. The cement content of the mix specified in Table-9 for any nominal mix shall beproportionately increased if quantity of water in mix has to be increased to over comeplacement and compaction so that specified water chemical ratio is not exceeded.
(e) BRICKS :
Bricks shall generally comply with IS : 1077 except in size which shall be conforming tothe sizes locally available. Depending upon the quality of bricks, they shall be_alvanized as 1st and 2nd class. (Class 7.5 & 10 as per IS : 1077-1992). Fly Ash bricksshould be as per IS : 12894 Class 7.5 & 10 as per IS : 12894-1992).
Bricks shall be the best quality locally available table moulded well burnt but notoverburnt have plane rectangular faces with parallel side and sharp right angled edges,have a fine compact, and uniform texture. The bricks shall be free from cracks, chips,flaws, stones or lumps of any kind and shall not show efflorescence either dry orsubsequent to soaking in water. It shall emit a clear ringing sound on being struck andshall not absorb water more than 20% by weight. Common building bricks shall have aminimum compressive strength of 75 kg./sq. cm. When used as panel in frame structureand 75 kg/sq.cm. for load bearing wall construction, unless otherwise specifically statedin the schedule of Quantities.
List of mandatory test:-Test shall be carried out for dimensions, compressive strength,water absorption, efflorescence in conformity as tested by methods laid in IS : 3495 or to clause 6.1.3,6.1.4,6.1.5 of CPWD Sub-head 6.0 for brick work.
(f) WATER :
Water for mixing cement/Lime/Surkhi mortar or concrete shall not be salty or brakish and shall be clean, reasonably clear and free from objectionable items of silt and traces of oil, acid and injurious alkali, salts, organic matte and other deleterious materials which will either weaken the mortar or concrete or cause efflorescence or attack the steel in reinforced cement concrete. Water shall be obtained from sources approved by the Architect. Potable water is generally considered satisfactory for mixing and curingconcrete, mortar, masonry etc. Where water other than main source is used this shall be tested in an approved testing laboratory to establish its suitability. All charges connected therewith shall be borne by the Contractor.
For concrete work water quality shall conform to Clause 5.4 read all sub-clauses ofIS:456-2000.
f) STONE :
The stone shall be of the type specified such as granite ,trap, lime stone, sand stone,quartzite etc. and shall be obtained from the querries as approved. Stone shall be hard,sound, durable, and free from weathering decay, and defects, that may adversely affect its strength and appearance .As far as possible stones shall be uniform in color, quality or texture. generally stones shall not contain crupst crystalline silica or chart, mica and other deleterious materials like iron oxide organic impurities etc. Stones shall be tested
for water absorption, transverse strength, resistance to water, durability, in conformity to clause 7.1.1,7.4,7.8,7.9 of CPWD specifications.
g) MARBLE/GRANITE:
Marble shall be hard,sound,dense and homogeneous in texture with crystalline texture as far as possible.It shall generally be uniform in colour and free from stains,cracks,decay and weathering. Granite shall be of any colour and size as directed and shall be plain machine cut and mirror polished .The stone shall be smooth and even surface without holes or pits.
Criteria for conformity shall be in accordance with table 8.3 and physical properties inconformity to table 8.2 of CPWD specifications.Marble/Granite shall be tested for Moisture absorption, hardness, specific gravity inconformity to Table 8.2/table 8.3
h) STEEL :
Elements such as niobium, boron, vanadium and titanium added singly or in combination to obtain higher strength to weight ratio and better toughness, formability and weldability as compared to unalloyed steel of similar strength level .Structural steel –standard quality shall conform to IS:228.
Testing for tensile strength, bend test, Flattening test shall be in accordance to IS:1599 ,IS:1609,IS :2329,IS :2328.Electrodes shall conform to IS:814.
Compliance of following shall be carried out wherever buildings are required to becertified as green buildings mentioned else where in the tender documents.
CREDIT ITEM ACTION REQUIRED
SS P1 Erosion and Sedimentation Control
Preparation and maintenance of gravel pit for all transportation site.
Top soil conservation for disturbed areas on site. Stacking,covering and re-spreading.Temporary or permanent seeding and mulching for undisturbareas.No over-loading of trucks is permitted and covering of soil wappropriate fabric or tarpaulin is ensured for all vehiclesentering or leaving site.
The soil recovered from excavation is either used off-site butensure that it never reach to the landfill.Sprinkling of water on loose soil during construction to checwind erosionConstruciton of _alvaniz graded swales and detention pondcheck soil erosion through storm waterCompare post development storm water run-off to predevelopment conditions.Fencing of boundary with filter fabric upto atleast 3m to cont dust.Development of erosion sedimentation control plan and follow National Building Code to carry out same.
SS CR 5.1 Reduced Site Disturbance:Protect or Restore habitat
Limit site disturbance including earthwork and clearing of vegetation to 40 feet beyond building perimeter, 5 feet beyond primary roadway curbs, walkways and main utility branch trenches, and 25 feet beyond constructed areas with permea surfaces that require additional staging areas in order to limi compaction in the constructed area.
SS CR 5.2 Reduced Site Disturbance:Development Footprint
Provide open space (excluding parking and roads) that exceeds the local zoning open space requirement for the site by 25%.areas with no local zoning requirements, designate open space area adjacent to the building that is equal to the buildingfootprint.
SS CR 6.1 Stormwater Design:Quantity Control
Implement a storm water management plan that results in a 2 decrease in the rate and quantity of storm water runoff.
SS CR 6.2 Stormwater Design:Quality Control
Reduce imperviousness, and promote infiltration. Storm water treatment system designed to remove 80% of Total SuspendSolids (TSS). Follow NBC (Part, Section 1, Clause5.2 – Storm Water Management & Filtration Techniques.
SS CR 7.1 Heat Island Provide shade or light colour - high albedo
Effect: Non-Roof
materials on at least 30%of the non-roof impervious surfaces
SS CR 7.2 Heat Island Effect: Roof
Provide any one of these:1. Vegetated roof on a 50% of roof surface. Utilize highreflectance materials for the rest of the roof area. 2. Use roofing material having Solar Reflectance Index equal or greater than 78 for a minimum of 75% of the roof surface.
SS CR 8 Light Pollution Reduction
Interior Lighting - Design lighting plan such that the maximum candela beam from the perimeter fixtures does not go outsidethe transparent or translucent part of the window. ORAll non-emergency interior lighting shall be automatically controlled to turn off during non-business hours. Provide manual override capability for after hours use.
External Lighting - Do not exceed 80% of the lighting power densities for exterior areas and 50%of the building facades a defined in ASHRAE/IESNA Standard 90.1-2004, Exterior light section, without amendments.
WE CR 4.1- 4.2 Water Use Reduction -20% OR 30% Reduction
Reducing the amount of water used in the building (excluding irrigation) by using water efficient fixtures (Low flow WCs, taps,urinals, etc).
MR P1 Storage and collection ofRecyclables
Allot an area on site that provides a space for the whole buildto store and segregate materials for recycling (paper, cardboard, glass, plastics and metals) both during construction and posoccupancy.
MR CR 1.1- 1.2 Building Reuse- Maintain75% AND 100% of _alvanizwalls, floors and roof.
Maintain 75% or 100% of existing building structure and shell excluding window assemblies and non-structural roofingmaterials.
MR CR 1.3 Building Reuse-Maintain100% of shell +50% of non- shell
Maintain 100% existing building structure and shell along wit50% non shell like internal partition walls, flooring, ceilingsystem etc
MR CR 2.1- 2.2 Construction WasteManagement- Divert 50%AND 75% from disposal.
Divert 50% or 75% of Construction waste and debris from landfill by recycle, reuse and salvage of the same.
MR CR 3.1- 3.2 Resource Reuse- 5% AND10%
Use salvaged, refurbished or reused materials, products andfurnishings for at least 5% or 10% of the building materials.
Use materials and products that are extracted within a radius 800km from the site that accounts for 50% of total buildingmaterials cost.
MR CR 6 Rapidly renewablematerials- 5% of buildingmaterials.
Use materials and products that are rapidly renewable andaccount for 5% of total building materials cost.
MR CR 7 Certfied Wood- 50% ofwood based materials
Use a minimum of 50% of the total wood requirements of thebuilding with wood from sources that complies with the Fore Stewardship Council criteria.
EQ CR 3.1 Construction IAQManagement
Develop and implement an IAQ management Plan for construction period. With this well being of the people working in the premises,
Plan- DuringConstruction
materials stored on site and if applicable, filters for Air Handling Units to be used during this time will be taken care of.
EQ CR 3.2 Construction IAQManagement Plan- Afterconstruction/ beforeoccupancy.
Develop and implement an IAQ management Plan for after construction and pre-occupancy time. With this well being ofpeople working in the premises, materials stored on site and applicable, filters for Air Handling Units to be used during thistime will be taken care of.
Use composite wood and agrifiber product that are free of urea formaldehyde resins and have low VOC content.
PART-CExecution of Items and Requirements:
This chapter gives guidelines and specification for executing various items for which theTenderer is required to quote rates in the chapter of Bill of Quantities. These specification are general in nature and but not exhaustive for all items of work. The items of civil work in general, will be governed by CPWD Specification for civil works and relevant I.S. Codes wherever there is any ambiguity in description or no description at all. The specific requirements over and above CPWD specifications/IS Codes have been dealt in detail in this chapter.
EARTH WORK & EXCAVATION
1. General 1 The contractor must satisfy himself as to the actual nature of the sub-soil by personally visiting the site. No additional charge shall be allowed for importing fill to
the site.
2. The contract rates for excavation shall be deemed to provide for excavation in any soil except in rock.
2. Site formation 1. Excavation and filling to building or over site, to make up or reduce levels in forming embankments, roads, paths, turfed areas etc. shall be carried out and graded to levels and falls as shown or as directed by the Architects. All filling to be with selected earth free from roots and all vegetable matter filled in, watered and well rammed and compacted to 95% of MDD achieved on same soil by Proctor Test in laboratory, as directed in layers not exceeding 200 mm thick. When filling to the final level allowance for settlement shall be given as directed by the Architects.
3. Excavation forfoundation of walls etc.
Trenches, column footings, etc. are to be excavated as per provision in CPWD or to such further dimensions as may be directed. Excavations shall be kept always dry by pumping out or bailing out any water that might accumulate (from whatever source it may be during the progress of the work without any extra charge by the contractor.
4. Planking and strutting
The Contractor is responsible for the design, fixing andremoval of all planking and strutting, shoring etc. of sufficient strength required to resist earth pressure and to ensure the safety of the workmen and the work to prevent damage to any adjoining property. No extra payment will be made on this account.
5. Bottom ofExcavations
The contractor is responsible for forming the bottom ofexcavations to correct levels and falls as shown required and thoroughly compact them to the satisfaction of the Architects before the lean concrete or soling is laid.
6. Excavationexceeding therequired or shown dimension
Should the contractor excavate wide and / or deeper than shown or directed, he shall fill up the extra excavation done by him with cement concrete 1:4:8 at his own expense.
7. Surplus Excavated
All surplus excavated materials is to be deposited, spread and _alvani as and where directed to or
Materials otherwise removed from the site as required by the Architects without extra cost.
8. Making up BedsUnder floors
Shall consist of approved earth free from all deleterious materials well rammed in layers not exceeding 200 mm thick. Water to assist compaction to be added at the direction of the Architects. The surface of the consolidated earth shall be dressed to the required levels and slopes.
9. Protection of existing trees
The contractor shall take all necessary steps required for the protection of trees existing on the site, as directed and to the satisfaction of the Architects.
10. Existing Pits and Wells etc
1. All old roots shall be grubbed up and old concrete or brick foundations, drains or manholes demolished and removed as required by the Architects. All old wells and mess pools etc. found during process of excavation shall be emptied and cleaned, connections where required, shall be sealed up, all contaminated earth shall be removed, voids filled in with hard, dry material , and well rammed at no extra cost
2. All existing buildings and constructions, public and private electric or sanitary or other utilities on the site shall be maintained by the contractor in working order and free of all damage during the excavation of the work. Any damage arising to the said utilities during this period shall be fully repaired by the contractor without charge to the The Corporation. However, any existing electric, sanitary or other service pipe or cables etc., if required to be removed by the Architects, the same shall be done by the contractorwithout any extra cost to the The Corporations. Allpermissions, sanctions of public authorities, government bodies required for the purpose shall be entirely the contractor’s responsibility
11. Grading The backfill of the gardens shall be brought upto therequired levels with layers of first class approved earth, spread over the entire area. This earth shall be free from weeds, coarse grass and other foreign materials and it shall be brought to an even surface exactly corresponding to slope to those shown or directed.
EARTH FILLING
1. SCOPE 1. This technical specification covers all work required forearthwork in site preparation in all types of soil including clearing, grubbing, _alvaniz, dressing, excavation, removing earth, dumping, backfilling with excavated earth and carted earth, compaction of back filling in site grading, embankments, approaches etc. covered under the scope of this contract
2. GENERAL 1 Work to be executed by the contractor
1 The work /items to be carried out by the contractorat his own cost in all respects, unless otherwisespecified, shall include but not be limited to thefollowing:-
1 Furnish all selected earth suitable for site gradingeither available excavated soil or brought from approved sources carry out at his own cost different tests to ascertain the quality and suitability of filling materials to be used as and when desired/instructed by the The Corporation/Consultant and submit the test resultsto the Engineer-in-charge, labor, supervision services, materials, scaffolds, earth moving and compaction equipments/ machinery, tools and plants, transportation, electricity, if required and water supply required for compaction etc., construction of necessary approaches required for execution of the work.
2 Submit to the The Corporation/ Consultant progressively, the result of tests undertaken to assess the degree of compaction attained in the backfilling/filling done for area grading at regular intervals as specified herein and also as and when required / instructed by the The Corporation/ consultant.
3 Excavation, removing, spreading/compaction etc.of earth filling shall be done with mechanical devices/ equipment/machinery for timely completion of the job.
4 Contractor shall maintain adequate drainage facilities at site at all times during execution of work. Additional ditches, drains and such other temporary means to
achieve this over and above whatever is shown in the drawings, will be provided and maintained by contractor at his own cost.
2. Adequate dewatering facilities like dewatering pumps.Piping etc. will also be provided by the contractor for thiswork and also for dewatering during excavation/filling etc.shall be supplied and utilized by the contractor forexecution of the work entirely at his own cost in allrespects
2. Information on site conditions
1 The layout drawing showing the contours of the ground indicating the existing ground levels and the formation levels to be achieved have been furnished to the contractor. The existing ground levels as shown in the drawing are only indicative and the tenderers must satisfyhimself fully about correctness of the same as also the character and volume of all work to be executed under this contract and expected surface levels and degree of compaction required to be attained, sub-surface and /orsub-soil water to be encountered etc. He must also satisfy himself about general condition of site including but not limited to the approach conditions and the temporary approaches to be constructed by him for movement of hisvehicles/ machinery/ equipment and materials / labour and ascertain the existing and future obstructions likely to arise/met with during the execution of the contract to carry out the work under his scope of work.
3 Condes and Standards
1 All work under this contract, unless specifiedotherwise, shall conform to the latest editions and /or revision and / or replacements of the specifications mentioned below or any other Indian Standard Specifications and Codes of Practice relevant to the work under the scope of this specification / contract:
i) CPWD specifications 1993 with upto date correction slips.
ii) Is: 3764 : Indian Standard for Safety Code for excavation work.
iii) IS : 2720 : Parts IV, V & VIII for ascertaining different characteristics of soil proposed to be used for filling.
2 In case any particular aspect of work is not coveredspecifically by Indian Standard Codes / CPWD specifications or this specification, then any otherstandard specification / good engg. practice as suggestedby the The Corporation/consultant shall be followed.Further, in case of any variation in the above, the morestringent specifications shall be applicable.
4. Conformity with design
1 Contractor shall carry out the work only as per theapproved drawings issued to him and / or as directed bythe The Corporation/ consultant. However the contractormust prepare more detailed drawings to facilitate theexecution of the work on the basis of the drawings issuedto him and should take approval of The Corporation/Consultant before starting the job.
5 The item of Earth work covered under this contract shallbe for all kinds of soil except rock. Accordingly, the ratesquoted shall be applicable for work in / with all kinds andtypes of soil except rock.
6. Materials to be used.
1 All material required to be used in the work under thescope of this contract must be to the satisfaction of theThe Corporation/Consultant and shall be of the best andselected quality available and to their approval.
1 Borrow Material
.1 Borrow material required for backfilling shall beexcavated from approved locations and shall consist of
granular material free from roots, vegetations, decayedorganic matter, harmful salts and chemicals, free fromlumps and clods and shall be of uniform quality.
.2 Arrangement for borrow materials from areas, stacks and/ or sources other than factory complex limit shall bedone by the contractor at his own cost. The rates forborrowed materials must cover the cost of excavation,loading , transportation, unloading, all leads, lifts, depthsand heights, royalty, octroi etc. nothing extra on anyaccount whatsoever shall be payable to the contractor.
.3 Only material considered suitable by the Engineer-in-Charge shall be used in earth filling for area grading andthat considered unsuitable shall be disposed off asdirected by Engineer-in-charge.
.4 The contractor shall give the samples of earth which heproposes to use for filling alongwith the followingcharacteristics of to Engineer-in-charge, prior to collectionand use for approval.
i) Mechanical analysis or grain size analysis as per Is: 2720part – IV
ii) Liquid limit as per Is: 2720 Part – V
iii) Plastic limit as per Is: 2720 Part-V
iv) Moisture density relationship as per Is: 2720 Part – VIII
.5 The material (soil ) used for filling shall be free fromboulders, lumps, tree roots, rubbish or any organicdeleterious matter.
.6 Material (soil) having plasticity index less than 20 onlyshall be used for filling purposes
.7 Soil having laboratory maximum dry density of less than95 lbs. per cubic ft. 1500 kg/Cu.m) shall not be used
.8 Care shall be taken to see that unsuitable waste material/ rejected material is disposed off in such a manner thatthere is no likelihood of its getting mixed with thematerials proposed to be used for filling.
.9 The work shall be so planned and executed that the bestavailable material (soil) is reserved for the top portion ofembankments
7 Quality Control
1 The contractor shall establish and maintain quality controlprocedures for the various aspects of the work, methods,materials and equipments used. The quality controloperation shall include but not be limited to the followingitems of work:
i) Lines, levels, grades: Periodic surveys, establishment ofmarkers and boards. Ensuring that the cutting/filling isdone to the required formation levels.
ii) Backfilling: Checking the quality of the fill material;checking the degree of compaction by standard test,checking moisture content of soil.
2. For carrying out the tests in accordance with Is-2720,Parts IV, V 7 VIII, as also for testing the degree ofcompaction attained in the field as also for ascertainingthe moisture content in the borrow material. All theequipment and the laboratory shall be maintained inperfectly good working condition during the entire periodof execution of the work and properly trained personnelwith necessary assistants shall be deployed by thecontractor all at the contractors cost in all respects. Thetests shall be carried out in the presence of therepresentative of The Corporation. Further as and whenso directed by the Engineer in charge, the contractorshall arrange to get the tests carried out in a laboratoryapproved by The Corporation. Nothing extra on anyaccount shall be payable.
8. EXECUTION
1. The contract shall set out the work as per the approveddrawings and as desired/directed by the TheCorporation/consultant and carry the Bench mark from aknown reference point as shown by the TheCorporation/consultant to the place of his work and fixpermanent points and markers for future reference. Toshow the correct formation level, necessary profiles withpegs, bamboo and strings etc. shall be made prior to thestarting of the work. The permanent points and markersshall be checked by the The Corporation and certified byhim, after which the contractor will proceed with the work.before starting any work on excavation or back filling, theexisting ground levels shall be jointly recorded by the TheCorporation. Consultant and the contractor and certifiedby the former and plotted on plans for the purpose ofrecord and measurement. The levels should preferablybe taken at an interval of 5 M in two perpendiculardirections but depending on the topography, the owner/consultant may instruct the contractor to take levels atany interval, the magnitude of which will be decided bythe The Corporation at his/their sole discretion. It shouldbe noted that the checking by the The Corporation shallin no way absolve the contractor or his responsibilities ofcarrying out the work to true lines, levels, grades andsubsequent correction at his own cost in case any error isnoticed at any time.
2. Clearing and Grubbing:
The area to be excavated of filled up with earth shall becleared out of fences, trees, roots, legs, stumps, bushes,grass, undergrowth vegetations, rubbish, slush, etc. and_alvani up. The The Corporation may, at his discretioninstruct certain trees or vegetation to be retained fromaesthetic or other points of view. The contractor shalltake due care and protect these while clearing the rest
ofthe area
2. The sequence of operation for clearing shall be asfollows:
.1 To clear the entire area of all grass, shrubs, jungle , wildgrowth undergrowth and remove all the roots andclearing/cleaning the area to make it fit to receive theborrow material for area grading. No extra payment forany such jungle clearance, removal of unserviceablematerial, removal of grass etc. shall be admissible.
.2 To survey and demarcate properly the area to be clearedas per the data supplied by the The Corporation.
.3 To take stock of all useful growth in the area and markthe trees required to be felled jointly with the TheCorporation.
.4 To uproot trees below 30 cm girth and cut in suitablelengths separating the branches
.5 To cut and fell all trees above 30 cm girth and cross cutthem in 4-5 metre length as directed by the TheCorporation / Consultant
.6 To remove all fences, poles, Tegs, firewood, existingstructures etc. transport and stack them in designatedlocations.
.7 To cut out all undergrowth scrub etc. stack them inconvenient and safe place for burning under strictsupervision.
.8 To take out roots upto 600 mm below ground level or 150mm below formation level whichever is lower. After thetree is cut and roots taken out, the pot holes formed shallbe filled with good earth in 200 mm layers and properlyconsolidated, unless otherwise directed by the TheCorporation/ Consultant.
.3 The contractor shall not be entitled for any payment for
such clearance/removal of grass, shrubs, fences, poles,jungle clearance etc. and for felling of trees of girth above30 cm (measured at a height of 1.2 M above groundlevel) in accordance with CPWD specifications – 1993Vols. I & II, wherever so directed.
.4 Before earthwork is started, all the spoils andunserviceable materials and rubbish shall be burnt orremoved from the site to approved disposal areas, asmay be specified. Ash shall be spread or removed asdirected. All useful material and poles, logs, firewood etc.thus obtained in the process of clearing shall be propertyof the The Corporation.The safety of nearby structures of works and without anyhindrance to the other activities in the area. Excavationshall be carried out from top to bottom. In certain caseswhere deterioration of the ground, upheaval, slips etc. areexpected, the The Corporation/Consultant may ordertemporary suspension of work in the area and mayinstruct the contractor to complete the balance work at alatter stage. The contractor shall not be entitled to anyclaims/damages / extension of time on any such groundwhatsoever.
.3 Compact of fill
.1 Approved fill material shall be spread in uniform layersnot exceeding 20 cms. In loose depth for site/ areagrading/embankment filling. Shoulder construction shallbe so _alvanize as to keep pace with the construction ofdifferent layers of the pavement, which may require earthfill thickness less than 20 cm. All clods, lumps etc. shallbe broken before compaction.
.2 In general the soil shall be spread uniformly over theentire width of embankment or shoulder / area pocket asthe case may be. For large embankments, the spreadingof soil shall be done as directed by Engineer-in-Charge.
.3 Successive layers of filling shall not be placed until thelayer under construction has been thoroughly compactedto satisfy the requirements laid down in thesespecification.
.4 Prior to rolling, the moisture content of material shall bebrought to within plus or minus 2% of the optimummoisture content as described in Is: 2720 Part – VIII. Themoisture content shall preferably be on the wet side forpotentially expansive soils.
.3 Earthwork in excavation and backfilling.
1. GENERAL
.1 All top soils shall be stripped from areas to be excavatedas shown on drawings and / or as directed by the TheCorporation/ Consultant to a depth of 200 mm andstacked within site and shall be filled back without anyextra cost . During excavation work as also during theentire period of execution of earth filling for site grading,the natural drainage of the area shall be maintained bythe contractor at his own cost. The final surface ofcutting and the top surface of the finally finished areashall be consolidated and neatly dressed so as to give aneven, neat and tidy look to the site.
.2 The area where filling is to be placed must be cleared ofall loose material and virgin soil must be exposed. Suchexposed surface must be consolidated properly to obtain95% of maximum laboratory dry density of the soil. Allsoft patches must be worked out to remove the soft soiland selected approved earth must be filled back andcompacted, at no extra cost.
.2 Payment for the removal of loose top soil and alsomaking up of soft patches, as described above shall beincluded in the rate for the item for earthwork in filling.No separate payment for consolidation of exposedground surface will be made. The rate quoted for the
earthfull shall be inclusive of the cost of clearing andstripping, consolidation including watering, testing etc. ofthe exposed ground
.2 Excavation in ordinary Soil, Hard Soil:
.1 Excavation shall be carried out as per contractorsproposal as approved and / or modified by the TheCorporation/consultant. The work shall be carried out ina coordinated manner without endangering
.2 After adjusting the moisture content as described abovethe layers shall be thoroughly compacted by means ofrollers till 95% of maximum laboratory dry density isobtained as per IS: 2720 Part – VIII.
.3 After adjusting the moisture content, the layers shall bethoroughly compacted by either sheep foot roller orpower driven roller 8-10 ton capacity or vibratory roller asapproved by Engineer-in-Charge till the specifiedmaximum laboratory dry density is obtained.
.4 Each layer shall be tested in field for density andaccepted by Engineer-in-Charge subject to achieving therequired density before laying the next layer. A minimumof one test per 500 sq.m for each layer shall beconducted
.5 If the layer fails to meet the required density and theconsolidation stipulated above, it shall be reworked or thematerial shall be replaced and method ofconstruction/consolidation altered as directed byEngineer-in-charge to obtain the required density
.6 Each layer shall be tested in field for density andaccepted by Engineer-in-Charge subjected to achievingthe required density before laying the next layer.
.7 The type of rollers that should be employed forcompaction shall be as per direction of Engineer-incharge
.8 The filling shall be finished in conformity with alignment,levels cross-sections and dimensions as shown in thedrawings
.9 Extra material shall be removed and disposed off asdirected by Engineer-in-charge
.10
Roots of trees, branches, leaves and other organic anddeleterious materials shall be removed from the areas tobe filled and from the excavated spoils as also from theearth used for filling before filling is started.
.11
Any damage to the embankments/filling due to rains shallbe made good by the contractor at his own cost
.12
The sequence of cutting and filing shall be as instructedby the The Corporation/Consultant
.13
The contractor shall mention the method of consolidationhe intends to adopt for the execution of thefilling/embankment to be done under this contract.Spreading, consolidation etc. must be done bymechanical equipment.
.4 Lead
.1 Excavated/borrowed earth shall be used for filling thefactory complex area as mentioned in the schedule ofitems only if found suitable and approved by the TheCorporation/Consultant. The rates quoted shall includeall leads and lifts and heights and depths unlessotherwise specified and no extra payment on any accountshall be admissible.
.5 Lift
.1 Rates quoted shall include work involving all lifts anddepths and no extra payment shall be made
.6 Dewatering
.1 At all stages of the work of excavation and backfilling, thework should be so planned that there is no accumulationof water. The contractor shall at his own cost in allrespects, make all necessary arrangements forprovision/operation and maintenance of pumps requiredfor dewatering whether before start of work or duringexecution of work under this contract. No separate claimfor dewatering shall be entertained for excavation andback filling/filling over areas /in embankments unlessmentioned otherwise
.7 Timber Shoring
.1 Timber shoring made out of approved quality timber shallbe of '‘closed’ or ‘open’ type depending on the nature ofsoil and the depth of pit or trench and the type oftimbering shall be determined by the TheCorporation/Consultant. It shall be the responsibility ofthe contractor to take all necessary steps to prevent thesides of trenches and pits from collapsing. No extrapayment for any timber shoring and strutting to be doneas per the site requirement shall be admissible
1. Close Timbering
i) Close timbering shall be done by completely covering thesides of the trenches and pits generally with short, uprightmembers called ‘polling boards’. These shall be ofminimum 250 x 40 mm sections or as directed by the TheCorporation /Consultant. The boards shall generally byplaced in position vertically in pairs, one board on eachside of cutting and shall be kept apart by horizontalwalers of strong wood at maximum 1.2 metres spacing,cross strutted with ballies or as directed by the TheCorporation/Consultant. The length of the bally strutsshall depend on the width of the trench or pit.
ii) In case where the soil is very soft and loose, the boardsshall be placed horizontally against the sides of the
excavation and supported by vertical walers, which shallbe strutted to similar timber places on the opposite faceof the trench or pit. The lowest board supporting thesides shall be taken into the ground. No portion of thevertical side of the trench or pit shall remain exposed, sothat the earth is not liable to slip out
iii) The withdrawal of the timber shall be done very carefullyto prevent the collapse of the pit or trench. It shall bestarted at one end and proceeded systematically to theother end. All care shall be taken to ensure that noportion of any concrete or masonry gets damaged duringthe removal of the timber. No claim shall be entertainedfor any timber which cannot be withdrawn and is lost orburied.
.2 Open timbering
.1 1 In the case of open timbering, the entire surface of theside of trench pit is not required to be covered. Thevertical board of minimum 250mm width and minimum 40mm depth shall be spaced sufficiently apart to leaveunsupported strips of maximum 500 mm average width.The detailed arrangement, sizes of the timber and thedistance, apart shall be subject to the approval of the TheCorporation/ consultant. In all other respects,specification for close timbering shall apply to opentimbering.
3. Rates 1 Earth work in excavation and back filling:
.1 The rates for earth work in excavation and back filling forthe soil as listed in the schedule of items shall include thecost of all materials consumed in the work, cost ofoperation and / or hire charges of tools, plants andequipment, cost of labour, insurance, transport, taxes androyalties, security and safety arrangements, power fuel,lubricant, services, accommodation, supervision,
overhead, profit etc. the rates should also include thecost of clearing and grubbing, dewatering, temporarystacking the excavated spoils and re-handling at a laterdate for back filling if required or disposing of the same iffound unsuitable as well as compaction as per clause2.8.6 of this specification. The rates shall also includeany temporary works like staging, sleeving etc. necessaryfor speedy and safe execution of the works, as also for allleads, lifts, heights and depths involved in execution ofthe work.
.2 Rates shall be quoted per Cu.M basis in schedule ofquantities. These rates shall be all inclusive and thecontractor shall not be entitled to any extra payments.
4. Method of Measurement
.1 . Clearing and Grubbing
No separate measurement shall be done for this item for the purpose of payment nor any separate / additionalpayment for this shall be admissible
.2 Earth work and back filling
No extra measurement for the purpose of payment shallbe done for temporary approaches, fencing and othertemporary works required to be done for the properexecution of the work
5. Control tests on earthbrought from outside
.1 Soil suitable for consolidation under O.M.C. conditionsshould preferably have the following characteristics:
a) Minimum percentage of clay 10%b) Liquid limit 14c) Plasticity index 4d) Percentage of silt should not exceed 50%e) Peat, muck and organic soils are unsuitable
.2 Various test required to be conducted on the borrowmaterial with their recommended frequency are
indicatedbelow. The frequency of testing indicated refersgenerally to the minimum number of tests to beconducted. The rates of testing must be stepped up asfound necessary depending upon the variability of thematerials and compaction methods employed at aproject.
a) Gradation: At least one test for each kind of soil. Usualrate of testing 1 to 2 tests per 8000 cu.m of soil.
b) Plasticity: At least one test for each kind of soil. Usualrate of testing 1 to 2 tests per 8000 cu.m of soil
c) Proctor tests: At the rate of 1 to 2 tests per 8000 cu.m ofSoil
d) Deleterious Contents: As required.
e) Moisture contents: one test for every 250 cu.m of sil
6. Tests for compaction
Field testing and random testing by external laboratories shall be conducted for all earth filling, at contractor’s cost, to ensure achieving of 95% of MDD compaction. The frequency of tests shall be as per norms stipulated in CPWD specifications
.ANTI-TERMITE TREATMENT
PART 1 – GENERAL
Work Included
This specification covers the Anti-Termite Treatment to the buildings.
Submittal
Submit manufacturer's literature, specifications and application instructions for insecticide materials for the reference of Engineer.
Environmental Conditions
Apply chemicals only when ambient temperature is above 40"F(5"C).
Qualifications
Operators to be trained and accredited and to work strictly in accordance with theManufacturer's specifications/ directions.
Protection
Protect surfaces not intended to have treatment.
Health and Safety
Observe health and safety precautions recommended by manufacturer.
Guarantee
Provide a Bank Guarantee for 10% of approved executed contract value against this work. If no defects are found 5% shall be released after five years and balance after ten years of the issue of handing over certificate.
Standards
The Anti-Terminate treatment shall conform to IS 6313 (latest edition).
PART 2 - PRODUCTS
ChemicalsThe Contractor shall use the following chemicals as Insecticides for the treatment :
a) Chloropyrifos EC 20% bearing ISI Certification or equivalent as approved by theEngineer.
PART 3 - EXECUTION
Treatment
1. Time of Application: Soil treatment should start when foundation trenches andpits are ready to take bed concrete/_alvaniz course in foundations, laying of bedconcrete/_alvaniz course should start when the chemical emulsion has beenabsorbed by the soil is and the surface is quite dry. Treatment should not becarried out when it is raining or soil is wet with rain or sub soil water. Treatmentto the surface of earth filling within the plinth shall also be done in the samemanner laying the sub-grade for flooring.
2 Treatment for Masonary Foundations & Basement:
a) The bottom surface and the sides (upto a height of 300mm) of theexcavations made for masonry foundations and basements shall betreated with the chemical at the rate of 5 litres per square metre surfacearea.
b) After the masonry foundation and the retaining wall of the basementscome up, the backfill in the immediate contact with the foundationstructure shall be treated at the rate of 7.5 litres per sqm. of the verticalsurface of the substructure for each side. If water is used for ramming theearth fill, the chemical treatment shall be carried out after the rammingoperation is done by rodding the earth at 150mm centres close to the wallsurface and spraying the chemical with the above dosage.
3 Treatment for RCC Foundation and Basements: In the case of RCC foundations,the concrete mix is dense (being 1:2:4 or richer). It is, therefore, unnecessary tostart the treatment from the bottom of excavations. The treatment shall start atthe depth of 500mm shall be determined from the new soil level resulting fromthe filling or cutting mentioned above and soil in immediate contact with verticalsurfaces of RCC foundations shall be treated at the rate of 7.5 litres per squaremetre.
4 Treatment of Top Surface of Plinth Filling: The top surface of the filled earthwithin the plinth walls shall be treated with chemical emulsion at the rate of 5litres per sqm of the surface before the sand/sub grade is laid.
5 Treatment at Junction of the Walls and the Floor: To achieve continuity of theverticals chemical barrier on inner wall surface from the ground level, a smallchannel 30x30mm shall be made at all the junctions of walls and columns with
the floor (before laying the sub-grade) and rod holes made in the channel uptoground level 150mm apart and the chemical emulsion poured along the channel@ 7.5 litres per sq.m of the vertical wall or column surface so as to soak the soilright to bottom. The soil shall be tamped back into place after this operation.
6 Treatment of Soil along External perimeter of Building: After the building iscomplete, 300mm deep holes shall be provided in the soil with iron rods along theexternal perimeter of the building at intervals of about 150mm and these holesshall be filled with chemical emulsion at the rate of 7.5 litres per sqm of verticalsurfaces.
If the depth of filling is more than 300mm, the external perimeter treatment shallextend to the full depth of filling up to the ground level so as to ensure continuityof the chemical barrier. In case the earth outside the building, this treatment shallbe carried out on completion of such grading.
7 Disturbance: The treated soil barrier shall not be disturbed. If for some reasonsthe treated soil barriers are disturbed. The same should be treated again to restorethe continuity and completeness of barrier system. Any repeat treatment carriedout to maintain the continuity should be measured separately.
.1 Provide all labour, materials and equipments necessary to executeall plain and reinforced concrete works shown in drawingsincluding concrete required for mechanical and electricalunderground services.
.2 Cutting and coring of concrete wherever required including thatrequired by mechanical and electrical trades is the responsibilityof the general contractor.
1.2 Standards .1 Indian Standard IS:456 "Code of Practice for Plain andReinforced Concrete" forms an integral part of this Section.Concrete work shall be carried out to the requirements of this Standard unless otherwise noted.
.2 IS:269, Specification for Ordinary, Rapid Hardening and LowHeat Portland Cement.
.3 IS:383 Specification for Coarse and Fine Aggregates fromNatural Sources for Concrete.
.4 IS:1786, Specification for High Strength Deformed Steel Bars and Wires for Concrete Reinforcement.
.5 IS:1199. Methods of Sampling and Analysis of Concrete.
.6 IS:516. Methods of Tests for Strength of Concrete.
.7 Reference to a Standard shall mean the latest edition of thatStandard.
.8 The contractor shall keep a copy of all the above IS codes for reference at site.
1.3 Samples .1 Provide samples of materials specified and as directed byENGINEER. at least 35 days before they are required for use. Deliver materials to site in time to enable further samples to be selected and tested to Engineer’s approval.
2.EXECUTION
2.1 Storage .1 Cement: store in a suitable building, protect against dampness and weather. Use in the order in which it comes to the site. Cement that has become lumpy or partially wet shall not be accepted and to be removed from site.
.2 Reinforcement: Store the reinforcement bars on supports above the ground.
.3 Aggregate: Deposit separately each type and size of aggregate on site at specified and prepared areas, Avoid contamination of materials and mixing of various types and sizes before use.
2.2 Reinforcement .1 Before being placed in work, clean off to the ENGINEER.'ssatisfaction loose mill scale, rust, oil grease, paint or othermaterial liable to impair bond, corrode reinforcement ordisintegrate concrete.
2.3 Aggregate .1 Sources : Source of material shall be such that qualitative material could be procured and it shall be subject to approval from engineer in charge. Do not vary source of supply without ENGINEER.'s knowledge or approval.
.2 Grading: Grading should be such as to produce concrete ofspecified strength and workability. If necessary, supplyseparately coarse aggregate in different sizes, combine on site as per the requirement of design mix.
COARSE AGGREGATE:
I.S. Sieve Designation
Percentage Passing for graded of nominal size
Aggregae
40 mm 20 mm 12.5 mm
75 mm 100 --- ----37.5 mm 95-100 -10019 mm --- 30-70 45-10016 mm --- --- -10011.2 mm 90-1009.5 mm 10 to 35 25-55 40-854.75 mm 0 to 5 0-10 0-10
a) Concrete to be Controlled Concrete, Grade of concreteshould be as per detailed structural drawings and confirm toIS:456 complying with following specific requirements.
Concrete mixes shall be so designed and the concrete soproportioned and produced as to provide an average compressivestrength sufficiently high to restrict the probability of strengthtests falling below the specified minimum to 1 in 10. Initially, therequired average strength value shall be calculated on an assumedvalue of the coefficient of variation to be 20%. The mixturesshall then be adjusted according to the actual value of thecoefficient as determined from a set of 10 site tests. For testingthe initial mix, one sample shall be extracted from each of atleast
four separate batches. For every initial trial mix each sampleshall consist of atleast of four companior cubes, two for testing atseven days and two for testing at 28 days. The average of all fourtests shall be equal to or greater than the required average strengthcalculated on assumption of coefficient of variation being 20%.
The proportions of ingredients for concrete shall be such that inaddition to complying with the strength requirement as statedabove, the concrete shall have adequate workability and properconsistency to permit it to be worked readily into the forms andaround reinforcement, under the conditions of placement to beemployed without excessive segregation or bleeding. Theminimum cement contents for concrete of various grades shall beas Per Latest edition of IS:456:2000
The mix required to produce, place and compact the specifiedgrade of concrete shall be designed by the contractor and detailsthereof submitted to the client for their record, along with theresults of sieve analysis and such other tests on cement,aggregates and water or on concrete as the clients may required.Design mix shall be tested from approved laboratory and testreports submitted to Employer. No concreting shall be carried outat site till this is done. These details shall then be scrupulouslyfollowing for subsequent concreting operations at site till avariation in some characteristics of any ingredient is observed ortill a variation in the degree of quality control necessitates achange in the mix. Full details of all such changes shall besubmitted to the clients for their record. All ingredients shall beproportioned and measured by weight using approved weighbatching equipment. It is to be clearly understood that mix design shall be the contractor’s sole and ultimate responsibility.Compression strength tests shall be conducted on the 28 day on15 cms works cubes and results evaluated . The contractor shallprepare all calculations, tabulations, graphs etc. pertaining to themix design and/or tests, as required by the clients. Copies of thesame shall be submitted to the clients and one copy shall be keptavailable at site. Contractor’s rates should include all these andno extras shall be entertained on this account.
b) Maximum aggregate size : Shall be as per drawings andspecification of item.
c) Proportions of fine coarse aggregate and cement, to besuch that, it shall produce mixtures workable concrete. Buthowever, in case of design mixer the proportion andgrading of concrete ingredients shall be strictly as per
design requirement to produce the concrete of requisitestrength.
d) Volume of coarse aggregate to be not less than volume offine aggregate.
e) Slump : As decided for each portion of the work byENGINEER.. Slump to the measured by ENGINEER.Using standard test confirming to IS:1199.
f) Design mix shall be as specified in respective items and asshown on drawings.
.1a Unless otherwise specified on drawing all concrete shall be designmix.
Batching:
Volume batching may be allowed only for weigh batching is not practicaland accurate nominal mix concrete where bulk deviation of material to beused in concrete have been established. Then procedure to convert mixproposition by weight to mix proportion by volume for nominal mixconcrete shall be as per CPWD specification of concrete work and shallbe got approved by the Contractor from EIC.
MIXING:
Concrete shall normally be mixed in a Batching Plant of adequatecapacity to mix batch of concrete requiring one or more whole bag of 50kg. cement.
TRANSPORTING OF CONC. BY PUMPS ONLY
Concrete shall be handled from the place of mixing to the place of finaldeposit as rapidly as practicable by methods which will preventsegregation or loss of any of the ingredients. For this purpose concreteshall be poured using pumps.
PLACING AND COMPACTING:
Unless otherwise approved concrete shall be placed in a single operationconstruction to the final position to the full thickness of slabs, beams andother similar members and shall be placed in horizontal layers notexceeding. 150 to 200mm. While concreting the member like beams,walls and girders the concreting should start from the ends to centre.
When concrete is to be placed at lower levels a covered chute with a slope by 1:2 to 1:3 should be used and it should be adequately supported on all sides. Concrete shall be thoroughly compacted during operation ofplacing and thoroughly worked around the reinforcement, aroundembodied fixtures and into the concrete corners of formwork.Compaction of Concrete: Mix like internal pin, external form, table, plateor screed vibrators should be used for compaction. Over vibration of verywet mixes is harmful and should be avoided.
STRUCTURAL JOINTS:
Expansion joints, contraction joints, dummy joints or other permanentstructural joints shall be provided in the positions and of the formdescribed in the drawings.
CURING:
Concrete shall be carefully protected after it is laid, against the action offrost and shielded from exposure to the sun which will cause too rapiddrying. All exposed surfaces and forms covering concrete are to becovered with not less than 1 inch of water by providing earthen bund onhorizontal surfaces and with jute or other approved suitable material onvertical faces. These shall be kept thoroughly and continually wet for aperiod of not less than 14 days after being deposited. Specialarrangements shall be made for holidays.
Tests: Following mandatory tests shall be conducted on RCC andreinforcement in CPWD Specification for RCC work.
1. Slump Test - Field/Lab2. Cube Test - Lab3. ReinforcementPhysical Tests:a) Ultimate Tensile strength Labb) Retest Labc) Rebend Test Labd) Nominal mass Lab/fielde) Bend Labf) Elongation Labg) 0.2% Proof Strenght Test Labh) Chemical composition Lab
Measurement of Materials:
a) Cement shall be used as per predetermined test in case ofdesign mix and by volume in case of volumetric mix.
b) Measure aggregates by weighing on an approved apparatus,which shall measure the weight of each separate fractionwithin an accuracy of one percent. The contractor shallarrange for the calibration of the weighing device before andduring the progress of the work.
c) Water may be measured either by weight or volume.
d) Only concrete produced through weigh batching shall beallowed for pouring purpose.
Mixing:
a) Mix concrete in a powered mechanical batch mixer of a typeapproved by the ENGINEER..
b) Do not load the mixer beyond the manufacturer's ratedcapacity which shall be sufficient to allow the use of one ormore complete packages of cement for each batch ofconcrete.
c) Continue mixing until there is uniform distribution of thematerials and the mass is uniform in colour and consistency.
d) Remixing of partly set concrete shall not be permitted.
e) Discharge the entire contents of the mixer before recharging.Clean the mixer after each period of continuous use; maintainin such condition that the mixing action shall not be impaired.
Placing:
a) Concrete placing shall not be started until the ENGINEER. hasinspected and approved all preparations including forms,reinforcing steel, construction joints, mixing, conveying,spreading, compacting, finishing, curing and protectionequipment.
b) The contractor to inform to the engineer well in advance ofplacing of concrete to facilitate checking and approval.
c) Convey concrete from the mixer to the point of deposit asrapidly as practicable, using means and equipment whichshall prevent separation or loss of materials.
d) Keep conveying equipment free from hardened concrete andforeign material. Thoroughly flush with water before andafter each run.
e) Deposit concrete in the forms as close as practicable to its finalposition; in layers that are approximately horizontal, not morethan 30 cm. Piling up of concrete in such a manner as shallallow the escape of mortar from the coarse aggregate shall notbe permitted.
f) Where necessary, place concrete through suitable vertical droppipes. Limit the vertical height of free fall to preventsegregation. Pour exposed walls in one continuous operationfrom floor to floor.
g) The size of section to be placed in one continuous operationto be as directed by the ENGINEER.. Depositing to becontinuous until this unit of operation is complete, andsufficiently rapid as to ensure the bonding of successivelayers and so producing a uniform texture. The maximumpermissible time interval between placing successive layers ofconcrete to be established by the ENGINEER.. Whereconcrete in deep beams, walls or columns is intended to bemonolithic with any member which they support, a delay toallow for vertical settlement of the concrete shall bescheduled before placing the upper concrete.
h) Place no concrete later than 1.5 hours after the mixing of waterto the cement and aggregates. No water shall be added to theconcrete at any time unless authorized by the ENGINEER..Compacting:
a) During and immediately after, all concrete to be thoroughlycompacted by means of approved mechanical vibration,supplemented by hand tamping to secure a densehomogeneous structure, close bond with reinforcement, andsmooth formed surfaces.
b) Use immersion type vibrators throughout. For thin walls orinaccessible portions of the forms, the concrete shall beassisted into place by vibrating, tapping or hammering formsopposite the freshly deposited concrete.
c) Apply the vibrator at any point, until the concrete iscompacted, and not for such a time that will cause
segregation. Great care shall be taken to ensure that thevibrators do not disturb the reinforcing steel or its bond topartially hardened concrete.
d) Vibrators are for compaction purposes only; do not use tocause concrete to more than a short distance.
e) If electric vibrators are used, mechanical vibrators shall bekept on site to take over in the case of power failure.
Curing and Protection:
a) After the concrete has set sufficiently, the exposed surfacesshall be kept continuously moist for at least 7 consecutivedays after placing, by means of water spray, wet sand or wetcement bags.
b) Protect freshly placed concrete from effects of direct sunshine,drying winds, cold excessive heat, and rain water by the useof adequate tarpaulins or other suitable materials to covercompletely or unclose freshly laid concrete.
c) Concrete in foundations and other underground work shall beprotected from adjoining falling earth during and afterplacing.
d) Adequately protect surfaces which are to be exposed in thefinished structure from defacement during operations. Shieldexposed corners of columns and walls from damage duringconstruction by means of wood cover strips or other approvedmeans.
e) Equipment needed for the curing and protection of theconcrete to be ready on site for the use before concreteplacing is commenced.
f) The contractor shall not allow the new structure to be loadedbeyond its capacity at any time. Loads from materials etc.shall be adequately distributed to the approval of theENGINEER..
3. Reinforcement .1 Bending and placing:
a) Prepare cutting and bar bending schedules for reinforcement and Submit two copies of schedules to the ENGINEER.I/C.
b) Make bends for beam and column ties around a pin having adiameter not less than twice the bar diameter. Make bends for other bars around a pin having a diameter not less than six times the bar diameter. All hooks shall be of the U-Type to the detail shown on the drawing. Any failure of bars duringbending shall be reported to the ENGINEER.. All bars shallbe bent cold.
c) Place reinforcement accurately and adequately secure inposition by concrete or metal chairs or spacers. Where therelevant concrete surfaces shall not be fully protected fromthe weather, all supports and distance pieces in contact withthe formwork shall be made of concrete or othernon-corroding material.
d) Secure reinforcement against displacement by tying atintersections with annealed wire ties. Welding ofreinforcement to be to the approval of the ENGINEER.. Bondwire ties away from nearby faces of forms, clear of theconcrete cover.
e) Support slab reinforcement at such intervals as shall ensure no undue deflection of the bars during placing of concrete.
f) Make splices in reinforcement only where shown in detaileddrawings.
g) Concrete cover to reinforcement to be as shown in thedrawings.
h) Where it is necessary to displace reinforcement from thepositions shown in the drawings to accommodate electrical,mechanical and other essential services, the conflict situation shall be brought to the notice of the ENGINEER. and his approval obtained before proceeding with any alternative details.
i) The placing and fixing of all reinforcement shall be to theapproval of the ENGINEER., and no concrete shall be placed before the reinforcement has been inspected and approved by the ENGINEER. The contractor shall give ample notice to allow time for the inspection and approval of the ENGINEER.
j) The contractor shall from time to time arrange for samplingand testing of reinforcement as per frequency laid in the List
of Mandatory Tests.
4 Formwork .1 Refer to the Architectural/Structural drawings for details offormwork required for various members of the structure.Formwork shall be in accordance with these details and asotherwise required to produce the surface finishes specified.Particular care shall be taken with the location and spacing of formwork ties and joints; failure to comply with theArchitectural/Structural drawings in this respect shall cause for rejection of the form work.
.2 Submit shop drawings of formwork at least two week beforeconstruction of formwork to ENGINEER. for approval.Contractor shall be responsible for adequacy and structuralstability of all form work.
.3 Build forms with sufficient strength and rigidity to carry theweight or fluid pressure of the concrete and of any equipment or runways which might be placed upon them. Brace properly and tie together so as to maintain position and shape and prevent leakage of mortar. Solidly back each butt joint with 75 x 75mm or 100 x 100mm members.
.4 Construct forms so that the finished concrete shall conform to the lines, shapes, grades and dimensions indicated on the drawings within acceptable limit of tolerances.
.5 Members used in the forms shall be free from wrap, twist and other defects.
.6 Provide temporary openings in column and wall forms, and other places where necessary, to facilitate cleaning and inspection. Locate these openings so that water for removing debris will have a clear run from the outside of the forms.
.7 Arrange forms for easy dismantling and stripping, so that removal will not damage the concrete.
.8 Do not start concrete placement until forms have been inspected and approved by the ENGINEER.. Check before pouring, tighten forms to take to shrinkage.
.9 Do not disturb forms without permission of ENGINEER..Minimum stripping times to be as set out in IS:456. Do notremove shoring until the concrete of various members has
attained required strength to support safely its own weight and imposed loads. Remove forms progressively, at approximately the same interval to ensure even colour; with care, so that corners of concrete members are not damaged.
.10 Shore the members adequately to cater the requirement ofadditional load during construction with safety for both, theirown weight and the load of such construction. Shore in successive storeys directly over those below.
.11 Formwork shall be marine plywood or other material approved by the ENGINEER. capable of resisting damage to the contact surfaces under normal conditions of erecting forms.
.12 Scaffolding and props for slabs, beams, stairs etc. shall be of steel and of adequate strength.
5.Construction Joints .1 The locations and details of construction joints shall be asindicated in the drawings or as directed by the engineer.
.2 Locate and design construction joints in such a way so thatstrength and appearance of the structure is least impaired.Continue reinforcement through the joint in its normal position. Provide shear strength across the plane of the joint by mortises or keys formed in the concrete, two directions where necessary. Form shear keys with _alvani strips.
.3 Before placing new concrete on or against hardened concrete, cut back surface of hardened concrete to dense sound concrete, remove debris and dust. Immediately before placing the new concrete, clean the existing surface with an air-water jet, work a 2cm. layer of soft mortar of the same proportions as that in the concrete, into the surface.
6. Inserts .1 Co-operate with all trades in the forming and setting of slots,sleeves, bolts, hangers, insert, conduit etc. Ensure that all is secure and not displaced during the placing of concrete. Place electrical conduit after the reinforcement is placed.
.2 Provide necessary chases, grooves and regulates. Supply and set bolts as shown or as required for setting of equipment and machinery.
.3 Refer to mechanical and electrical drawings for concrete bases, sumps, man-holes, pits openings etc.
7. Tolerances The followings tolerances shall apply to this work :
.1 Variation from the plumb
a) In the lines and surfaces of columns and wallsIn 10 ft. (3 meters) 1/4" ( 6mm)In any storey or 20 ft. (6 meters) 3/8" (10mm)In 40 ft. (12 meters) or more 3/4" (12mm)
b) For exposed corner columns and other conspicuous lines In any bay or 20 ft. ( 6 meters) 1/4" ( 6mm)
I n 40 ft. (12 meters) or more 1/2" (12mm)
.2 Variation from the level or from grades indicated on the drawings.
a) In floor surfaces, beam and slab softies (measured before removal of supporting shores)
In 10 ft. (3 metre) 1/4" ( 6mm)In any bay or 20 ft. ( 6 metres) 3/8" (10mm)In 40 ft. (12 metres) or more 3/4" (20mm)
b) For exposed lintels, sills parapets, horizontal grooves and other conspicuous lines.In any bay or 20 ft. (6 metres) 1/4" ( 6mm)In 40 ft. (12 metres) or more 1/2" (12mm)
.3 Variation from plane surface. Surfaces designed to be plane shall not deviate more than 3/16" (5mm) when tested with straightedge 10 ft. (3 metres) long. Surfaces designed to be of shapes other than plane shall be of similar accuracy.
.4 Variation of the linear building lines from established position in plan and related position of columns, walls and partitions.
.5 Variations in cross-sectional dimensions of columns and beams and the thickness of slabs and walls.
.6 External concrete pavements.
a) Departure from established alignment 1/2" (12mm)b) Departure from established longitudinal grade 1/4" ( 6mm)
c) Departure from transverse template contour 1/4" ( 6mm)
.7 Reinforcement
a) FabricationSheared length 1" (25mm)Overall depth of cranked bars +0 -1/2" (12mm)Overall dimensions of ties +0 -1/2" (12mm)All other bends 1/2" (12mm)
b) PlacingSpecified distance from formwork 1/4" ( 6mm)Top bars in slabs 8" (20mm) or less 1/4" ( 6mm)Top bars in slabs thicker than 8" (20mm) 1/2" (+12mm)and in beams
8. Patching Defective Areas .1 All concrete to be subject to inspection and approval by the ENGINEER. after the stripping of the formwork and before any finishing or patching work has been commenced.
.2 Permissible defects are those which, in the opinion ofENGINEER., can be repaired as described below, without impairing the strength and, in the case of exposed work, the appearance of structure. Other defects shall make the work liable to rejection or repair as may be directed by the ENGINEER..
.3 The following describes methods of repair for permissible defects: Defective concrete shall be removed to reveal sound concrete but in no case to a depth of less than 1" (25mm). The area to be patched and an area at least 6"(15mm) wide surrounding it, shall be dampened and the exposed concretecoated with a neat cement mortar grout mixed to the consistency of thick cream, well brushed into concrete surface.
The patching mixture shall consist of cement and sand mixed in the same proportions as used in the concrete. A blend of white and grey Portland Cement shall be used to achieve a colour match with the existing work. The quantity of mixing water shall be the minimum required for the handling and placing.
.4 Cavities left by formwork ties shall be filled neatly as described above for repair of defects.
.5 Replace all pathway / road panels damaged during laying of service lines. Wherever a panel is damaged the full panel shall be removed and a new panel cast in accordance with existing specification of pathway / road. No patchwork is permitted.
9. Precast Concrete .1 All the forgoing requirements of this Section apply to concrete shown on the drawings as being precast.
.2 Handle precast concrete sections subsequent to their casting in such a manner as to prevent them being loaded their capacity at any time. Protect corners as necessary to prevent damage during erection.
.3 Provide mortar bedding under all precast concrete sections in the structure as necessary to provide even bearing.
.4 Formwork for precast concrete sections to be as required to produce surface finishes matching those on adjacent cast-in-place concrete.
CIVIL / ARCHITECTURAL SPECIFICATIONS
VACUUM DEWATERING SYSTEM
General
1. The requirements on the quality of industrial floors have rapidlybecome more excavation during the last few years. The reason for thisis mainly the use of fork lift trucks and other modern transportequipment. The increased wheel loads require higher compressivestrength and wear resistance of the floor then before with increasinglift heights higher accuracy as to the flatness of the floors become aprerequisite.
2. These demands of course lead to a further checking of traditional floorplacing methods and to development of new building methods. TheTREMIX vacuum dewatering technique, which is described here,satisfies these high quality requirements. In addition, this methodoffers several advantages, e.g. lower manufacturing costs.
3. According to traditional floor placing methods, a base course is firstplaced. This base is then covered with a topping. This topping whichmay consist of one or several courses, must be placed very carefully.Therefore, it is quite a hard work. The topping must have a good bendto the structural concrete if it is to function in operation and in traffic.Problems like break-away of the topping are usual on this type offloors.
In spite of similar initial materials, the physical properties of concreteand topping are different. Both layers behave differently at varyingtemperature-weather and environment conditions. This may lead tostresses in the floors for lintels, such stresses are desirable but not forindustrial floors as they cause separation of the topping from the baseconcrete cracking and finally break-away. A repair is then inevitable.Repair are not only expensive but also associated with costlyinterruptions in production and cause dust and noise problems.
4. The use of the TREMIX vacuum dewatering method is specified forthis section.
This method follows the well known laws of the concrete technologyand construction. For full utilization of the advantages of theTREMIX vacuum dewatering system, the following points should beobserved already at the planning stage.
Base
1. If the industrial floors are placed directly on the ground, the base musthave a sufficient bearing capacity. If necessary frost protection layersare placed on free surfaces on appropriate filling material for floors inhalls or hangars.
2. At this work and also at the ensuring concrete placing careful attentionshould be paid to the calculation of the expected traffic loads, keepingin mind also these often bigger ones which occur during theconstruction work.
3. If industrial floors are placed as suspended floors, the usual conditionsregarding frame work and static loads are valid.Service Location
1. The position of the pipes for water and drainage, heating, electricsupply and telephones must be fixed before concreting starts so they donot hinder the concreting work.
Joints
1. Through vacuum processing shrinkage is reduced by 5-75%.Compared to that of normal concrete. Correspondingly, joint spacingcan be increased on vacuum dewatered industrial floors. Jointless bays20x20mm are possible. One condition for this is, however, that thestability of the base and the construction including reinforcement iscalculated with regard to future traffic loads.
Also on suspended floors the joint distances can be increased. At theexecution, however, attention must be paid to the stresses of theconstruction. The joints must be expansion joints which give enoughroom for the movement of the concrete. Expansion joints can as a rulebe _alvanize on fixed bases for flat industrial floors.
Particle Share
1. The grading for the aggregate should be in the region A B 32.Preferably as near the line A 32 as possible. The amount of fined(sand) should be as small as possible.
Cement
1. Cement (ordinary _alvaniz) is particularly suitable as binding agent.Cement content should be at the lowest limit. The total filler contentconsisting of cement and fine particle, should be limited to a minimum.
This factor is of great importance both for the vacuum and for thereduction of shrinkage.
Water
1. In order to increase the workability concrete should have a plasticconsistency of K2 / K3. Slump between 8-13 cm.
Shop Drainage
1. Produce shop drawings as and when required by Engineer prior tocommencement of the work.
2. Vacuum concrete should be made according to standard DIN-104 withregard to concrete quality you must not use so much water that runs onits own into the form-work. Even if the excess water is then extractedduring the vacuum treatment, the quality of the concrete would suffer.There are the exacting demands of the standard DIN 1045 should beobserved.
Admixture
1. A pre-test of the admixtures, if used, is to be carried out in order todetermine their suitability for vacuum dewatering.
Standards
1. DIN-1045 is also valid for vacuum concrete. If a concrete withspecific properties for example impermeability, high frost resistance,high resistance against chemicals and high wear resistance is required,the prescriptions of paragraph 6, 5, 7 if the standard are to be followed,even if vacuum dewatering improves these properties further.
Quality
1. The improved properties of vacuum concrete can be proved by takingspecimens from cores or 35cm cables. The cubes are made in aTREMIX laboratory apparatus called TM1.
Work Cycle for Process
1. The TREMIX vacuum dewatering process has been developed in orderto _alvanized_ the concrete work and to achieve high quality concretefloors.
2. This system id advantages to anyone involved in building projects to
the designer as it means high quality and new aspects on the practicalwork, to the contractor trouble free application on sites, to theestimating engineer noticeable costs savings and finally, to the endused durability and reduced maintenance costs.
3. The work tear also enjoys the system. The previously usual, verytiresome _alvaniz with a board does not exist any more. Now, thereare handy machines with comfortable working positions.
Concrete DIN 1045 Levelling – Din 18.202
1. Concrete of consistency class K2 / K3 (8-12 cm slump) is placed eitherby pump, crane skip or direct from concrete truck. The next step as_alvaniz which is carried out with TREMIX surface vibrator.
The surface vibrator, available in lengths of 3 to 12m, consists of alight alloy double beam. The beam is provided with tensioning rods toprevent deflection. The TREMIX surface vibrator leaves a concretesurface within the tolerance region of DIN 18.202, line 6 or 7.
Execution, Vacuum, Dewatering
1. The purpose of vacuum processing if the removal of surplus waterfrom the concrete to provide quicker setting and earlier maximumstrength properties. Vacuum dewatering takes place immediately afterthe screeding operation.
2. Upon the surface of the wet concrete is place a filter pad consisting oflayers, the bottoms layer in contact with the concrete is fine nyloncloth to act as a filter. The upper layer consists of a special type ofplastic not and acts as water duct. Finally, the top cover consisting of atight plastic sheet is placed over the filter and projecting slightlyoutside on all sides. The border of the top cover rests directly upon thewet concrete to produce an air tight seal.
The suction mat is connected with suction to a vacuum pump. Thenormal atmospheric pressure in the pump is reduced by 90% and 90%of the atmospheric pressure compresses the concrete.
Concrete is submitted to a pressure of:
Air pressure 0.10 N/sq.mm (1.0 Kp/sq.cm)
Depression 0.01 N/sq.mm (0.1 Kp/sq.cm)
Effective pressure 0.09 N/sq.mm (9.0 Kp/sq.cm)
3. This pressure of about 9000 Kp/sq.mm compresses the concrete andcompacts the aggregate. At the same time the excess water which isnot necessary for the hydration process of the cement is extracted fromthe concrete and continuously discharged with the air.
4. Apart from normal compaction through vibrator, static compaction ontaken place during vacuum dewatering with ensuring reduction of theW/C ratio. The initial W/C ratio is reduced by 10 to 20%. Thisexplains the noticeable improvement of the concrete propertiesachieved through vacuum dewatering. Vacuuming time is abt. 1 to 2min/cm thick concrete slab takes about 30 minutes to dewater.Accordingly, a normal daily production rate is about 400 mt.
5. Floating and Trowelling
Immediately after vacuum dewatering the surface is power floated witha skim-floater. The floating disc leaves a rather rough structure whichis suitable for marking decks and industrial floors where a non-slipperystructure is required. If a smoother surface is required, the surface istrowelled with the same machine provided with trowelling blades.
The floating and trowelling operations take place within one hour fromconcreteing. The advantage, when compared to other methods, is thatthe binding process of the cement is not yet over at this time and thematerial is still live. In addition, usual waiting times of 2 to 20 hours,depending on concrete consistency, ambient temperature and weathercondition, are eliminated.
The starting time for the trowelling operation can be determined inadvance. It means tire savings as well as improved quality andincrease of production.
Curing
1. After trowelling, which is the last step of the TREMIX vacuumdewatering method, concrete is cured in the normal way. The surfaceis covered with a plastic sheet or a curing compound. In hot climateconcrete is to be covered with wet burlap and kept moist.
2. Curing should be made with care to prevent damage from wind andsun in order to achieve optimum quality properties.
CIVIL / ARCHITECTURAL SPECIFICATIONS
DRIETOP FH
WORK INCLUDED
Provide and install all equipment, material, and labour to complete work of this section in accordance with the details herein over all vacuum dewater surfaces. Also refer Schedule of Items.
PRODUCTS
Drietop Floor Hardener FH
Manufactured by M.C. Bauchemie/Fosroc or approved equivalent.
EXECUTION
The form works should be erected and _alvani as per designed bays.
The base should be cast of RCC concrete having water cement ration of not more than 0.4 incorporating an high early strength super plasticizer like Zentrament F BV and the concrete should be properly vibrated by screed vibrators.
The cement content should be minimum of 300 kg/cu.m.
When the surface is free from residual bleed water and is sufficiently hardened to allow light foot traffic and when the surface leaves an impression of about 2 to 3mm the try shake, surface hardener like Drietop FH manufactured by MC-Bauchemic (India) Private Ltd. can be broadcasted. The broadcasting should be done in two operations which are perpendicular to each other.
The surface can then be power floated and power trowelled to achieve desired finished.
Drietop FH should be used @ 6 Kg/sq.m.
The floors can be cured in a normal way.
After complete curing the surface should be well prepared and free from oil, grease and remnants of form oil or curing compound. The surface should be free from dust, laitance and completely dried. Surface driers can be used if residual moisture is observed on the surface.
Bricks shall conform to the latest Indian standard specification (ISS) Bricks shall be whole, sound, well burnt, free from cracks, to ring when struck and not to crack or break when soaked in water regular in shape and uniform in size. They should be of the best of description/class designation obtainable in the market, and of the best quality and colour, and in every respect to be approved by the Architect unless otherwise specified they should be of F.P.S Bricks of size 22.5x11.1x7.0 cm. No bricks to absorb water more than one fifth of their own weight when dry for use in load bearing walls. For bricks used in panel walls, the water absorption shall not exceed one fourth of their dry weight. Bricks to be thoroughly cleaned, well wetted or soaked in fresh water before being used on the work, and no broken bricks to be used except as closures. Specified brick quality shall be sampled as per IS :5454 – 1978 and tested as per IS : 3495 – 1976. The bricks shall meet the criteria as per IS : 1077 – 1992 for Burnt Clay Bricks or IS : 12894-2002 for Fly Ash Bricks when tested as mentioned herein.
1.1 Tile Bricks
Tile bricks of 4 cm height shall be moulded without frogs. Where modular tiles are not freely available in the market, the tile bricks of FPS thickness 4.4 cm (1.8”) shall be used unless otherwise specified and shall be of clause designation 75.
1.1 Brick Bats
Brick bats shall be obtained from well burnt bricks.
1.2 Classification
The common burnt clay bricks shall be classified on the basic of their minimumcomprehensive strength as given in the table below :
TABLE – 2 CLASSIFICATION OF BRICKS
ClassDesignation
Average compressive strength(kg/Square cm)
Not less than Not more than
100 100 125
75 75 100
50 50 75
35 35 50 The bricks of class designation 100 shall have smooth rectangular faces with sharpcorners and emit ringing sound when struck. Tolerance on dimensions upto ±3% shall be permitted.
The bricks of class designation 75, 50 and 35 may be permitted to have slight distortedand round edges provided no difficulty shall arise on this account in laying of uniformcourses. Tolerance on dimensions upto ±8% shall be permitted.
1.4 Sampling
For carrying out compressive strength, water absorption efflorescence and dimensionaltests, the samples of the bricks shall be taken at random according to the size of the lot as given in Table – 2 below. The samples thus taken shall be stored in a dry place until the test are made.
TABLE – 2
BrickDesignation
Loss Size Sample Size
100 More than 50,000 bricks 20 bricks
75 More than 1l00,000 bricks 20 bricks
5015
1.5 Soaking of bricks
Bricks required for masonry in cement mortar or composite lime mortar shall bethoroughly soaked in clean water before use for at least six hours and until air bubbles cease to come out. The soaked bricks shall be kept on wooden planks or bricks platform to avoid earth being smeared on them. Bricks required for masonry with mud or flat lime mortars shall not be soaked.
1.6 Mortar
All brick work shall be laid with specified mortar to be prepared in proportion described in schedule of items. It shall be of cement and coarse sand and shall be made in small quantities so as to be used up within 30 minutes. It shall be mixed to a sufficiently thick consistency as required by the Architect. No left over mortar shall be used. The mortar proportion to be used shall be as specified in the relevant items.
1.7 Laying
Brick work shall be carried out as per IS : 2212. Brick work shall be laid in English Bond unless otherwise specified. Half or cut bricks shall not be used except when needed to complete the bond. Each course shall be perfectly straight horizontally and transverse. The walls shall be taken up truly plumb, if battered, the batter is to be truly maintained. The plumb of the brick work in vertical walls shall be checked up at every one metre interval.
1.8 Raking back of walls at angle
Walls of all structures shall be carried up regularly in all cases, leaving no part, one metre lower than another. If this cannot be adhered to, the brick work shall be raked back at an angle not more than 45 degree so as to maintain a uniform and effectual bond, but raking back should not start within 60 centimetre of a corner.
Buttresses, Counterforts, etc.In all cases returns, _alvanized, counterforts etc. are to be built up course by course carefully bound into the main walls.
1.8.1 Junction of Walls
At all angles forming the junction of any two walls, the brick shall, at each alternate course, be carried into each of the respective walls so as to thoroughly unit the work. The brick work shall not be raised more than 14 courses per day.
1.9 Joints
Joints shall be restricted to 1.0 cm for brickwork with bricks of any class designation (unless any wider vertical joints upto 10mm are necessary to give the required thickness of the wall) All bed joints shall be normal to that pressure upon them i.e. horizontal in vertical walls, radial in arches and at right angles to the face in battered retaining walls.The vertical joints in alternate course shall come directly one over the other and shall be truly vertical. Care shall be taken that all joints are fully filled with mortar. (proportion as specified in Bill of Quantities) well flushed up and in case where struck as the work proceeds. The joints in `faces which are to be plastered or pointed shall be squarely raked out to a depth of 12mm while the mortar is still green. The raked joint shall be well brushed to remove loose particles. After the work, the faces of the brick work shall becleaned with wire brush so as to remove any splash of mortar during the course of raising the brick work. Before jointing the brick work with new brick work, old brick surface shall be raked brushed, cleaned and soaked with water.
1.10 Fixtures to be provided
All iron fixtures, pipes, conduits, drains, sleeves, bolts, holdfasts of doors and windows and other inserts of services and all other trades of works etc. which are required to be built in walls, shall be _alvaniz in cement mortar 1:3 ( 1 cement : 3 sand) or in cement concrete 1:3:6 ( 1 cement : 3 sand : 6 coarse aggregate) as per requirement to suit site conditions in their correct position as the work proceeds.
1.11 Brick Coping and Cut Corners
The top course of all plinth, parapet, steps and top wall below RCC shall be laid with brick on edge, unless specified otherwise. Care shall be taken than the bricks forming the top courses and ends of walls are properly radiated and keyed into position.
1.12 Protection and Curing
Green work shall be protected from rain by suitable covering. The work shall also be suitably protected from damage, mortar dropping. Brick work as it progresses shall be kept thoroughly well watered on all faces for at least 10 days after completion. Proper watering cans with nozzles must be used for this purpose. The top of brick work shall be left flooded at the close of the day by forming fillet of mortar 40 mm high round the edges of top courses and filled with water.
1.13 Scaffolding
Double scaffolding sufficiently safe and strong so as to withstand all loads likely to come upon it and having two sets of vertical supports shall be provided. Where two sets of supports are not possible the inner end of the horizontal scaffolding pole shall rest in a hole provided in the header course only. Only one header for each pole shall be left out. Such holes however shall not be allowed in pillars under one metre in width or immediately near the skew backs of arches; Such holes shall be filled up immediately after removal of scaffolding properly.
1.14 Half Brickwork
Bricks used for half brick wall shall be as specified above under para 1.1. It shall be laid in 1:4 cement mortar exactly in the same manner as described earlier except that all courses shall be laid with stretchers. The brickwork shall be reinforced with 2 nos. hook iron strips 25mm x 1.6 mm embedded at every third course for the whole length of the wall as per standard practice. Cost of hoop iron strips shall be deemed to be included in the rate.
1.15 Lateral Support for Walls
For half brick walls, no panel shall be greater than 8 square metere and side longer than 3.0 m. If the panel exceeds the length mentioned above, the bricks at 3.0m intervals shall be replaced by a RCC column of same width and shall be further tied to the structure by providing 100 x 200 mm continuous RC beam at lintel level. Cost of such RC works would be deemed to be covered under unit rate of brickwork.
1.16 Brick Tile work
The work shall be done in the manner as described in the Brick Work except that brick tile shall be used instead of bricks.
1.17 Mortar:
Shall be as specified and conform to accepted standards. Lime shall not be used wherever reinforcement is provided in brick work. Preparation and mixing of mortars shall be as per clause 3.2 in CPWD specifications.
AUTO-CLAVED AERATED CONCRETE:
General:
AAC blocks can be used in load bearing and non load bearing applications in external and internal walls.AAC blocks conform to IS2185(partIII) and masonary is carried out as per IS 6041(1995) and IS 1905(1987).They can be cut with carpenters handsaw,drilled nailed by using normal handtools For chasing give two cuts with marble cutter and chisel out material.Mortar(1:6) of 10 mm thick required for masonary work.Do not use mortar richer than 1:6 in AAC block masonary.Prior to masonary only the face in contact with mortar required to be wetted.Curing shall be carried out for 3-4 days.
Raw material in AAC
Flyash:55-60%Gypsum:2-3%Cement:10-12%Lime:12-14%Aluminium powder:0.03%Balance slurry solids generated during process
Properties of AAC BlocksDensity (Oven Dry) :550-650 kg/cumCompressive strength :min.30kgs/cm2Thermal conductivity :0.162w/mk(average)Resistance to fire: 2-6 hrs.depending on thickness.Drying shrinkage:0.02%Design gross density :850Kgs/cum(appx.)
