Specification for Concrete Work

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Specification for concrete

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SPECIFICATION FOR CONCRETE WORK

CONTRACT REF.: PROJECT NO.: XXXX

PROJECT TITLE:

DOCUMENT TITLE :SPECIFICATION FOR CONCRETE WORK

MAIN CONTRACTOR

ENGINEERING CONSULTANT

TABLE OF CONTENTS1INTRODUCTION61.1SCOPE61.2APPLICABLE CODES, STANDARDS AND SPECIFICATIONS62MATERIALS92.1CEMENT92.2AGGREGATES102.3WATER122.4ADMIXTURES122.5REINFORCING STEEL142.6ANCHOR BOLTS162.7INSERT PLATES / EMBEDDED PLATES172.8MISCELLANEOUS ITEMS173CONCRETE MIX DESIGN183.1GENERAL183.2CEMENT CONTENT183.3WATER/CEMENT RATIO183.4TOTAL SALT CONTENT IN CONCRETE193.5USE OF ICE AS MIXING WATER194TESTS FOR CONCRETE194.1GENERAL194.2SLUMP TEST194.3WORK CUBE TEST195GROUTING235.1TYPES OF GROUTS235.2PREPARATION OF GROUT245.3SURFACE PREPARATION245.4FORMWORK FOR GROUTING255.5WEDGES AND SHIM PLATES255.6PLACING, CURING AND TESTING255.7FINISHING OF GROUT276FORMWORK276.1GENERAL276.2FORM WORK FOR VIBRATED CONCRETE287TRANSPORTATION AND PLACEMENT287.1TRANSPORTATION287.2PLACEMENT287.3COMPACTION297.4TOLERANCE307.5FINISHES318CURING358.1HORIZONTAL SURFACES358.2VERTICAL SURFACES358.3CURING COMPOUND359REMEDIAL WORK3610READYMIX CONCRETE3611PROTECTIVE COATINGS3711.1GENERAL3711.2CASTING ONTO SOIL3711.3SURFACE BELOW SOIL3711.4ABOVE GRADE CONCRETE PROTECTION3812PRE-CAST CONCRETE3913THIRD PARTY INSPECTION39

PROJECT SPECIFICATIONS3771-MGDA4-1-14-0001Specification for Structural Steelwork

QP STANDARDS AND SPECIFICATIONS-QP standard specification civil works, Volume 1.

QP-SPC-L-002QP Technical Specification for Painting and Wrapping of Metal

QP-PHL-S-001QP Corporate Philosophy for Fire and Safety

QP-REG-S-001QP Safety Regulations for Contractors

ES.D.-10Engineering Standard for Drafting

QP-STD-A-001QP Accepted International & National Standards

INTERNATIONAL CODES AND STANDARDSThe following BS codes unless otherwise specified herein shall be applicable. In all cases the latest revision of the codes shall be referred to:BS EN 197-1:2000Specification for Ordinary and Rapid hardening Portland cement

BS EN 1992-1-1Euro code 2-Design of concrete structures.

BS EN 206Concrete. Specification, performance, production and conformity.

BS EN 196Methods for testing cement

BS EN 12620Aggregates for Concrete

BS EN 1008Mixing water for concrete, Specification for sampling, testing and assessing the suitability of water, including water recovered from processes in the concrete industry, as mixing water for concrete

BS EN 934Admixtures for concrete, mortar and grout (Parts: 2, 6)

BS EN 933Tests for geometrical properties of aggregates Determination of particle shape

BS EN 12504-1Testing concrete in structures. Cored specimens. Taking, examining and testing in compression

ASTM C-33Standard Specification for Concrete Aggregates

ASTM C-109Standard Test Method for Compressive Strength of Hydraulic Cement Mortars

ASTM C-227Tests for Potential Alkali Reactivity of Cement Aggregate Combinations (Mortar Bar Test Method)

ASTM C-289Test for Potential Reactivity of Aggregates (Chemical Method)

ASTM C-494Standard Specification for Chemical Admixtures for Concrete

ASTM C-579Standard Test Methods for Compressive Strength of Chemical-Resistant Mortars, Grouts, Monolithic Surfacing and Polymer Concretes

BS 1881Methods of Testing Concrete.

BS 4027Specification for Sulphate Resisting Portland cement

BS 4190ISO Metric Black Hexagon Bolts, Screws & Nuts

BS 4320Metal Washers for General Engineering Purposes

BS EN ISO 1461Hot dip galvanized coatings on fabricated iron and steel articles. Specifications and test methods

BS 4449Specification for carbon steel bars for the reinforcement of the concrete

BS 4482Specification for cold reduced steel wire for the reinforcement of concrete

BS 4483Specification for steel fabric for the reinforcement of the concrete

BS 6031Code of practice for earthworks

BS 8000Workmanship on building sites

BS EN 1338Concrete paving blocks, requirements and test methods

BS EN 12350:Parts 1 to 8Testing fresh concrete

BS EN ISO 5667Water quality. Sampling Guidance on the preservation and handling of water samples

BS 6100Building and civil engineering terms

BS 8666Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete

BS EN 1993Design of steel structures -Part 1-1: General rules and rules for buildings

BS EN 1997-1Geotechnical design - Part 1: General rules

BS 6089Assessment of concrete strength in existing structures

BS 6093Design of Joints and Jointing in Building Construction

MATERIALSCEMENTTYPE OF CEMENTCement shall be supplied from a source that has a well-established, proven record for consistent supply of quality materialOrdinary Portland cement conforming to BS EN 197-1 or equivalent shall be used for all concrete works both in sub structure and super structure. Sulphate Resisting Cement (SRC) complying with BS 4027 shall be used for blinding and mass concrete. CONTRACTOR shall use cement manufactured by Qatar National Cement Company (QNCC), subject to availability. All cement shall comply with part-1, section-5 of Qatar construction specification. Source of materials shall be subject to QP approval.TESTSTest for cement fitness, soundness, strength test (compression) and setting time shall be carried out in accordance with BS EN 196 for each shipment of cement.CEMENT STORAGEThe cement shall be suitably protected during storage to avoid deterioration in quality. Cement must be ordered well in advance to ensure an adequate and continuous supply. Cement shall be of recent manufacture and shall be used within a period of 3 months from production.Cement that has been in storage for more than 3 months (from the date of manufacture) shall not be used.Cement stored in bags under a shade should maintain relative humidity level not exceeding 60%. Any damaged bag of cement will be rejected. It must not contain lumps that cannot be crushed between fingers. Any cement with incipient setting or traces of humidity shall be rejected.Bagged cement shall be delivered to site in the Suppliers original sealed bags or containers and shall be stocked in a dry, weather tight, properly ventilated covered structure, with adequate provisions for preventing the absorption of moisture and raised at least 150 mm off the ground to prevent deterioration. Suitable shade/ covering shall be provided to limit the temperature to 40C.AGGREGATESSOURCESAggregates shall be obtained from an approved Qatari source unless CONTRACTOR can show that local materials are not available.All aggregate to be used for concrete shall comply with part 2, section 5 of QCS. Source of material shall be from GABBRO only. CONTRACTOR shall supply physical characteristics of the materials including samples and test, for QP review and approval.All aggregates used for the same structure shall be obtained from one source.Dune and beach sand shall not be used as fine aggregates.Fine and coarse aggregates shall conform to BS EN 12620. Fine and coarse aggregates shall be considered as separate ingredients. Both shall meet the grading requirements of BS EN 12620. They shall be well graded, clean, hard and free from undesirable material. The clay, silt and fine dust content, the organic impurities and the aggregate crushing value, shall be within the limits specified in BS EN 12620.TESTSThe CONTRACTOR shall take samples from stockpiles for testing in the Contractors site laboratory. Any material which, as a result of such test, does not conform to the requirements of BS EN 12620 shall be removed from the site by the CONTRACTOR at his own expense. All samples shall be taken in the presence of QP Representative.Aggregates test result shall be presented to QP for approval.Aggregate shall be tested in accordance with BS EN 933 or equal and shall meet the requirements of table 2.1, part 2, and section 5 of QCS.Aggregates shall be tested for any materials that are deleterious reactive with the alkalis in the cement. They shall also be tested for alkalis which are additionally present in the aggregates and mixing water, in amounts sufficient enough to cause excessive localized or general expansion of concrete or mortar, as described in ASTM C 33 when tested in accordance with ASTM C 227.Marine aggregates are prohibited.The maximum dust content of aggregates as determined by wet sieving through a 75m sieve as per BS EN 933 shall not exceed the following limits: Coarse aggregatesi. Natural or crushed gravel- 1 %

ii. Crushed rock- 3 %

Fine aggregatesi. Natural or crushed gravel- 3 %

ii. Crushed rock- 5 %

Chlorides in coarse aggregates shall be limited to 0.03% by weight and to 0.06 % by weight in fine aggregates and a cumulative total content of chlorides in concrete required shall be as specified in section 4.4.1.Sulphate in the coarse aggregates shall be limited to 0.3 % by weight and 0.4% by weight in fine aggregates and a cumulative total content of sulphates in concrete required shall be as specified in section 4.4.2.Aggregate shall be tested for reactive silicates in accordance with ASTM C-227 and ASTM C-289, or to be obtained from a supplier whose aggregates have previously been proven to meet these requirements. Compliance certificates shall be submitted to QP. Aggregates meeting the requirements of ASTM C-289 do not require testing as per ASTM C-227.Testing shall be carried out at the following frequency: Test for clay, silt, dust, moisture content and sieve analysis shall be carried out on every 20 tons of fine aggregates and 40 tonnes of coarse aggregates delivered to the site, with a minimum of each test once per day; Chemical analysis shall be carried out on every 100 tonnes delivered to site, with a minimum of each test once per week; andQP shall have the right to call at any time for additional samples for testing of aggregates delivered to the worksite or for the aggregates at the source of supply in order to conform that the aggregates meets the specified requirements.SIZECoarse aggregates shall be limited to 20 mm maximum single size.Fine aggregates shall be limited to 5 mm maximum size.Sand shall be graded so that, when mixed with coarse aggregate and cement, it shall produce a concrete of maximum density. Crushed sand may be added to natural sand in proportions to achieve required grading. Crushed sand alone is not acceptable without the approval of QP. GRADING OF AGGREGATEGrading of aggregates shall be in accordance with Table 2.3 and Table 2.4 of QCS Section 5, Part 2. STORAGEAggregate shall be stored under shade. Storage shall prevent contamination of the aggregates by foreign material. Wet aggregate shall be kept on site for at least 24 hours to ensure adequate drainage before being used for concreting.The concrete plant shall at all times maintain sufficient quantities of each type of aggregate to be sufficient to ensure continuity of work.Fine and coarse aggregates shall be separated by permanent substantial partitions in the store. Fine and coarse aggregates from different sources of supply shall not be mixed or stored in the same stockpile. Methods of storing and shading aggregates shall be approved by the QP.WATERWater used for the following, shall comply in all respects with requirements of BS EN 1008 and BS 6068 and QCS Section 5, Part 4. Mixing of concrete; Ice production; Rinsing aggregates; Cooling aggregates; and Curing of concrete.Only clean, fresh water free form harmful matter shall be used. Chlorides (Cl) and Sulphates (SO3) shall be within permissible limits as specified in BS EN 1008.The water shall not contain dissolved solids in excess of 2000 mg/kg. It shall be clean and free from sugars, phosphates, acid, vegetable, and deleterious matter (e.g. oil) that affects the properties of concrete. The pH of the water used shall be between 7.0 and 9.0.CONTRACTOR shall arrange for analyses of samples of the mix water to be made before and during the programme of the work by approved testing laboratory.If any samples prove unsatisfactory, the CONTRACTOR will be required either to change to a new supply or to make arrangements acceptable to QP to remove the unacceptable constituents at his own cost.ADMIXTURESNo admixture shall be used without QP approval of the specific admixture, manufacturer, dosage and application. Ready-mixed concrete for all reinforced applications shall contain a super plasticizing set-retarding admixture complying ASTM C494 type G. All admixtures to be used for concrete shall comply with Part 5, Section 5 of QCS. Source of material shall be subject to QP approval. All admixtures used to modify one or more characteristics of the concrete shall be accompanied by a certificate from an approved institute, stating: Exact range and method of application; Physical and chemical composition; Positive and negative side effects; A recommendation on the maximum allowable quantity (as a percentage of the mass of the cement) to achieve the particular requirement; Proportioning and mixing; and Compatibility of the admixture with the type of cement used.CONTRACTOR shall perform the trial batch and casting to substantiate the manufacturers claims for workability, retardation and air entrainment (0 to 0.1 percent maximum). No air-entraining agent is to be used.Admixtures shall not contain chlorides.As a general rule, only one admixture may be used to improve a given quality of concrete. If a retarder and plasticizer are required only a dual-purpose additive shall be used.Admixtures shall be applied strictly in accordance with the manufacturers instructions. However CONTRACTOR shall be responsible for any defective concrete that may result from the use of such admixtures.Following precautions shall be taken, in the use of the different admixtures: Admixture shall comply with the requirements set forth in part 5, Section 5 of QCS; Admixture shall only be used following the written approval of QP; Admixtures shall be in accordance with BS EN 934 or ASTM C-494-80 type G; Admixture shall not affect long term strength of concrete; and CONTRACTOR to be aware that the admixture may increase shrinking and cracking (accelerating admixtures). Where admixture dosage is to be adjusted depending upon atmospheric temperature, mix design shall include details of admixture dosage vs. atmospheric temperature range; Dosage of any plasticizing admixtures, including super plasticizers and water-reducing admixtures, shall not be greater than 85% of the admixture manufacturers recommended maximum dose; Where it is proposed to use more than one (1) admixture, CONTRACTOR shall submit manufacturers data, independent technical evaluations and/or trial test results confirming compatibility of the combined admixtures and demonstrating no undesirable short or long term effects in the concrete. Mix design document shall include details of order and method for dosing each admixture; Some admixtures may promote excessive bleeding and segregation, in which case they may be used only if site trials prove those aspects does not occur.Very strict controls are to be maintained to ensure that the correct quantity of admixtures is used at all times. The equipment to be used for dispensing and the method of incorporating the admixture in the concrete shall be subject to approval of QP. The dispensing unit shall be translucent so that the operator can see the discharge of the admixture.Precast concrete pipeline sleepers shall have corrosion inhibitor DCI-S by grace construction products or other QP approved equivalent included in the mix at a rate of 20litres/m3.REINFORCING STEELMain reinforcing steel bars shall be un-coated high yield deformed bars of characteristic strength of 414 N/mm2 to BS 4449, or equal as supplied by Qatar Steel Company (QASCO), designated as grade T.Uncoated mild steel plain bars with characteristic strength of 250N/mm2 to BS 4482 or BS EN 10025-1 may be used for links and binders, designated as grade 'R'.Steel wire fabric shall be of characteristic strength 485 N/mm2 in accordance with BS 4483 or equal.Adjacent sheets of mesh reinforcement shall be overlapped by at least 300 mm or 31 times the diameter of the wires lying at right angles to the edges to be lapped, whichever is greater. Laps shall be tied together on both longitudinal and transverse wires.Mechanical bar couplers, where required, shall be specified as complying with the requirements of BS EN 1992-1-1.Reinforcement shall be fixed, supported and maintained in position by the adequate use of chairs, spacers and tying wire.A copy of the manufactures test certificates for ultimate strength, bend elongation and cold bending together with the chemical analysis of the steel shall be submitted to QP for each consignment of the reinforcing steel delivered to site.STORAGEReinforcement shall be stored on site above ground on rack, is such a way that it shall not be damaged both before and after bending. It shall be stored in separate lots by size and by type.Reinforcing bars with different diameters or different grades shall not be mixed during the storage. The storage methods shall facilitate easy retrieval of bars. Both ends of each bar must bear a painted mark identifying its grade.Rack shall be covered to prevent corrosion by rain.QUALITY CONTROL & WORKMANSHIPAll reinforcement shall be fully detailed including bar bending schedules for fabrication. Bar bending, cutting and detailing shall be as per BS 8666.Bending shall be in cold condition. Re-bending of high yield bars is not permitted.All reinforcement shall be free of loose rust, grease, paint oil and any other matter, which may adversely affect adherence within concrete.Reinforcement shall be accurately placed as shown on drawings. Reinforcement shall be set true to line and level with the correct concrete cover as specified on the drawings. CONTRACTOR is to provide sufficient support, by means of approved chairs, spacers, tying wire etc., to ensure that all reinforcement is held in the correct position while concreting is taking place.Reinforcement shall be rigidly bound together at every inter-section of two bars by 1.60 mm soft annealed iron wire binding (No.16 SWG). All starter bars shall be set in position prior to concreting and securely held during concreting.Welding of reinforcement will not be permitted unless CONTRACTOR can demonstrate that the bars are of weldable quality, meeting requirements of BS 4449.Concrete spacer blocks shall be made from materials in no way inferior to those specified for the concrete in which the spacer block is to be used. (For example, spacer blocks used in concrete work below ground shall incorporate sulphate-resisting cement). Plastic spacer block is not permitted. CONCRETE COVERMinimum clear concrete cover to all steel reinforcement including links shall be as follows: Cover for all concrete works in contact with soil including foundations, and pedestals up to base plate level shall be 70mm.Cover to all above grade concrete exposed to weathering shall be 50 mm.Cover to above grade concrete protected from weathering shall be: Beams, columns and external surfaces of walls- 40mm Slabs and internal surfaces of walls- 30mmCover to bar couplers shall not be less than the minimum specified for reinforcing bars.Blinding concrete shall not be considered as cover. ANCHOR BOLTSThe design of the anchoring length of the anchor bolts shall be checked for maximum pull-out force. Anchor bolts, pipe sleeves, anchor rails, inserts, bolts, etc. shall be positioned accurately and be firmly attached to the formwork before the concrete is poured. Installed anchor bolts, etc., shall be properly protected against damage and corrosion until the equipment/structure is permanently installed. A template shall always be used to hold the anchor bolts in their correct position. The template shall be of rigid construction and fabricated from a suitable robust material and subject to approval of QP. All anchor bolts installed to 2 mm of their design position. Anchor bolts shall be plumb to +/- 1:100.Level tolerance to top of bolts shall be 0 mm + 10 mm. Anchor bolts shall be of Grade 4.6 conforming to BS 4190. Grade 8.8 shall only be used with prior approval of QP. Washers shall conform to BS 4320. Anchor bolts, nuts and washers shall be hot dip galvanized in accordance with BS EN ISO 1461. Each anchor bolt shall be adequately anchored into concrete.Forging and heating of anchor bolts is not allowed. Anchor bolts shall be designed for combined tension and shear as per BS EN 1993.Before installation anchor bolts shall be de-greased by soaking them in Tri-Chloro Ethylene at least for 4-6 hours. Use wire brush to remove grease and scale.Entire anchor bolt assembly including bolt, nuts, washers, cast-in plates, etc. shall be hot dip galvanized to BS EN ISO 1461. The minimum edge distance to concrete plinth from the centreline of the anchor bolt shall be as follows:Bolt SizeMinimum Edge Distance

30 mm diameter150mm

> 30 mm diameter175mm

The distance between anchor bolts, within an anchor bolt group shall conform to the tolerance limits listed below:Center to center Distance between Anchor Bolts (mm)Tolerances (mm)

Less than 400 1.5

400 to 900 3

900 to 1200 4.5

Greater than 2000 6

The minimum distance from base plate grout to edge of concrete plinth shall be 75mm.Adequate reinforcement shall be provided in concrete plinths to transfer the design tension and shear from anchor bolts to the foundation. Vertical reinforcement in concrete plinths shall be provided with sufficient anchorage length above and below the bottom of anchor bolts.INSERT PLATES / EMBEDDED PLATESInsert plates shall be of the material and size as shown on the drawings and standards.Insert plates in the horizontal plane shall be installed so as to ensure that the variation from level does not exceed 1.5 mm per 300 mm in either direction, and that the centre of the surface of the insert is within 0.75 mm of the elevation shown on the drawings. Insert plates whose least dimension is greater than 300 mm shall have sufficient weep holes to ensure full bearing.Insert plates in the vertical plane shall be installed so as to ensure that the variation from plumb does not exceed 0.75 mm per 300 mm. The centre of the surface of the insert shall be within 1.5 mm of the vertical surface and within 3 mm of the location and elevation as show on the drawings.Shear keys may be required in particular cases, for the insert plates in order to transmit horizontal loads to the foundations. In these situations back up design calculations and justifications shall be provided to QP for approval.All insert plates should be sand blasted and hot dip galvanized to BS EN ISO 1461 before their installation.MISCELLANEOUS ITEMSAll miscellaneous items related to concrete works shall comply with Part 16, Section 5 of QCS.All sleeves, inserts, anchors, angle steels and other embedded items required for adjoining work or for its support shall be accurately placed and firmly anchored to prevent displacement prior to concreting.All cast-in-place steel items shall be hot dip galvanized to BS EN ISO 1461. All steel surfaces that are in direct contact with cured concrete surfaces shall be painted prior erection to ensure the durability of non-corrosion surfaces in short period of time. Touch-up paint on steel members shall be carried out with the same colour-coding.CONCRETE MIX DESIGNGENERALThe mix shall be a special prescribed mix in accordance with BS EN 206 and as specified in this document except that the relative proportions of the fine and coarse aggregates and the workability of the concrete shall be determined by the tests carried out on the site before normal production of concrete commences.Blinding concrete shall be a designed mix with a characteristic strength of 20 N/mm2.Mass concrete shall be a designed mix with a characteristic strength of 20 N/mm2.Structural concrete shall be a designed mix with a minimum characteristic strength of 40 N/mm2.The concrete mix shall be designed to have an initial setting time of not less than 3.0 hrs.CEMENT CONTENTCement for structural reinforced concrete and paving shall be Ordinary Portland Cement to BS EN 197 or equivalent. Cement content shall be limited to whats required for durability to avoid excessive risk of thermal and shrinkage cracking. For reinforced concrete of grade C40/20, it shall not be less than 370 kg/m3 unless otherwise approved by QP.Sulphate Resisting Portland Cement (SRC) complying with BS 4027 shall be used for blinding concrete, mass concrete and other unreinforced concrete. For blinding concrete of grade C15/20 (SRC), cement content shall not be less than 280 kg/m unless otherwise approved by QP. For mass concrete of grade C20/20 (SRC), cement content shall not be less than 310 kg/m unless otherwise approved by QP.WATER/CEMENT RATIOThe proportioning of mixes for durability will be primarily controlled through the specified limits of free w/c ratio and workability.A maximum water/cement ratio of 0.45 shall be allowed for all reinforced concrete works and 0.55 for all blinding/ mass concrete works.The water/cement ratio shall be continuously checked at the mixer with due allowance being made for water (if any) contained in the aggregates. Under no circumstances is additional water to be added between the mixing and the place of concrete placement. Additionally, the water/cement ratio shall be checked by tests carried out on fresh concrete at the time of placement and by slump test, all as described in section 5.0, of this document.TOTAL SALT CONTENT IN CONCRETECHLORIDESThe total contents of chlorides shall comply with the requirement of Table 6.2, Part 6, and Section 5 of QCS.SULPHATESThe total sulphate content shall comply with requirements of Table 6.2, Part 6, and Section 5 of QCS.USE OF ICE AS MIXING WATERFor the purpose of this clause, mixing water shall be defined as the maximum amount of water that may be added to the mix after taking due account of the water present in the aggregate.The target temperature for "as mixed" concrete shall be 20C minimum and 25C maximum. These temperatures may not be attainable during certain periods of the year. The maximum temperature during these periods may be increased to a maximum 32C as it enters the formwork. This requirement can be met, provided, mixing water with flaked ice and/ or chilled water below 40C. The water shall not be chilled below a temperature of 1C.Mix temperatures, of concrete, greater than 32C shall not be used.TESTS FOR CONCRETEGENERALTests to be carried out for concrete shall comply with Part 6, section 5 of QCS and all other relevant codes quoted in QCS and this Project Specification.If a plasticizer/ admixture is used in concrete, tests shall be carried out to determine the initial setting time.SLUMP TESTSlump tests shall be carried out on fresh concrete, at the time of placement, at the rate of one test per truck. Tolerance shall be -15 mm/+35 mm for design slumps less than 100mm and -20mm/+40mm for design slumps of 100mm and over. True slump shall be between 50 mm and 100 mm for concrete without super-plasticizer.WORK CUBE TESTSampling and testing shall be carried out using the relevant procedures set out in BS 1881, BS EN 12350 and BS EN 12504-1.Samples for cube tests shall be taken at an average rate of one per 30 m3 of concrete placed, for pours up to 100m3;, one per 50 m3 of concrete placed, for pours between 101 and 500 m3; one per 100 m3 of concrete placed, for pours greater than 500 m3 with a minimum of one sample for every reinforced concrete pour unless noted otherwise. At the time of taking samples for cube crushing, other samples shall be taken simultaneously for the analysis of cement content and water/ cement ratio of fresh concrete, in conformity with BS 1881.Samples shall be taken at the point of discharge from the mixer or delivery vehicle, if ready-mixed concrete is being used. From each sample, six 150 mm cubes shall be made, three for testing at 7 days after casting and three for testing at 28 days. All cubes shall be clearly marked with their identification and accurate records shall be supplied to QP giving: Identification of test cube; Date and time of sampling; Mix designation; Location of sampled batch after placing; Method of compaction; Date of testing; Result of test; Cement type and country of origin; Volume of pour; Age of sample in days; Weigh of cube in grams; Density in kN/m3; Crushing load in N; Crushing strength N/mm2; Signature of person preparing cube; and Signature of person crushing cube. Concrete is deemed to comply with this specification provided the 28 days cube crushing result, which shall be grouped consecutively in groups of 40, have the following for each group:i. Standard deviation less than 3.5 N/mm2;ii. No result more than 7 N/mm2 below the mean; andiii. No result lower than 28 day nominal strength.The sampling, making, curing and testing of test cubes shall be in accordance with BS EN 1992-1-1, BS 1881, BS EN 12350, BS EN 12504-1 and section 5 of QCS. Full scale trial mixes shall be carried out in accordance with BS EN 206 and BS EN 1992-1-1. Test shall be carried out as per following clauses:CONCRETE GRADE C40The trial mix proportions must be in accordance with this specification for cement content and water cement ratio. The materials to be used in the trial mixes shall be representative of those to be used in the permanent works. The actual strength of the concrete, for prescribed mix as defined in BS EN 206 will be above the design strength. A super-plasticizer may be required and if so should be used in the trial mixes. The required workability for large foundations will differ from that for tall thin sections of structural concrete cast above ground and the trial test should allow for both cases. When a suitable mix has been established to the satisfaction of QP, then six separate trial mixes shall be prepared and six 150 mm test cubes shall be made from each trial mix.All the 36 cubes shall be tested (3 from each mix at 7 days and 3 from each mix at 28 days) and the mean strength and standard deviation established. Additionally, 4 initial surface absorption tests (ISAT) on 12 non-oven dried (air-dried) samples shall be made in accordance with BS 1881 part 5. The trial mix shall be accepted if: The mix proportions and slump including water cement ratio and cement content are as defined in this specification; The standard deviation is less than 3.5 N/mm2; The works test strength of any cube is not below 40 N/mm2 at 28 days and The trial mix strength of any cube is not below 50 N/mm2 at 28 days.If the absorption rates are less than the following it will not necessary for the test to run for 2 hours.Time after standing testISAT result mL/m/s

10 min0.25

30 min0.17

1 hr.0.10

CONCRETE GRADE C20The trial mix proportion shall be in accordance with this specification for cement content and water cement ratio. Three separate trial mixes shall be prepared and three preliminary test cubes shall be made from each mix for testing at 28 days. The trial mix shall be approved if the average strength of the nine cubes is not less than 30 N/mm2 for grade C20. Once the trial mix proportions and water/cement ratio has been accepted for grades C20 concrete, they shall not be changed without the agreement of QP. CONTRACTOR and QP shall monitor the mix proportions and water/cement ratio. UNSATISFACTORY CONCRETEIf any cube strength is below 40 N/mm2, then the concrete in the pour shall be removed and replaced at the Contractor's expense.If the standard deviation of the group of 40 cube result exceeds 3.5 N/mm2 or if the lower result is more than 7 N/mm2 below the mean, then concrete production shall be stopped and method of concrete production shall be investigated by CONTRACTOR. Further tests on trial mixes may be required by QP at Contractors expense. Concrete with a standard deviation greater than 3.5 N/mm2 and/or with a cube crushing test result more than 7 N/mm2 below the mean shall be acceptable, provided the requirements of above are fully complied with and CONTRACTOR implements all recommended actions resulting from the investigation to ensure future concrete is of greater consistency. If the unit represented by the sample is questionable, QP may instruct CONTRACTOR the following actions as appropriate. Change of mix; Improvement of quality control; Cutting testing cores from placed concrete; Load testing relevant structural units; and Cutting out and replacing defective unitIf the range of individual cube strength made from the sample exceeds 15 % of the mean, then the methods of making, curing and testing cube shall be checked. In the event of result having a range exceeding 20 %, the result shall be unacceptable and QP may order any actions outlined in a) to e) above. If the core test strengths are less than 90 % of characteristics strength, the concrete shall be cut out/ replaced.SEVEN DAYS CUBE TESTThe results obtained from the tests carried out on moulded cubes at 28 days shall be the means of ensuring that the concrete meets the compressive strength requirements of the specification. Test shall be carried out at 7 days to establish a relationship between the 7 days and 28 day strengths. The relationship shall be used to interpret further test result in order to predict the probable value of the corresponding 28 days strengths.QP shall be informed immediately, of any sample, which fails to meet the Specification so that necessary action can be taken to minimize the effect of such failure.PERMEABILITY TESTPermeability tests are to be carried out with initial surface absorption tests of concrete (ISAT) in accordance with BS 1881 -Part 5 Routine test shall be carried out on the in-situ cured uncoated site concrete at location chosen by QP at the rate of six locations for two tests per week. Both horizontal and vertical surfaces shall be considered for testing. The concrete so tested shall be considered satisfactory if the absorption rates are less than the following:Time after standing testISAT result mL/m/s

10 min0.25

30 min0.17

1 hr.0.10

It will not be necessary for the test to run for 2 hours.Concrete, which fails the test, is suspected as being pervious to the penetration of chlorides and as such, QP may call for its removal and replacement at the CONTRACTORs expense. The causes of the failure shall be investigated and additional absorption tests on the same age may be called for.GROUTINGGrouting refers to all work to be carried out to properly fill with mortar the space between concrete surfaces and base plates of equipment, steel structures or concrete prefabricated elements in order to achieve adequate transfer of horizontal and vertical forces. Grouting to be used shall comply with part 16, section 5 of QCS. The QP shall approve all grout materials and application procedures. TYPES OF GROUTSNON-SHRINK GROUTSA grout is regarded as non-shrink if its volume is not less than the initial volume after hardening for 28 days.The type of non-shrink grout shall be as specified on the drawing and/or specification.During this period the test specimens shall have been completely protected against drying, evaporation, carbonation and exposure to temperatures greater than those stated as accepted by SUPPLIER.CONTRACTOR shall submit the Manufacturers data sheets and certificates for QP approval.The grout shall be free of chlorides and shall have a pouring consistency. A metal-oxidising or gypsum-forming non-shrink grout shall not be used.Two types of commonly used non-shrink grout are as follows: Cement-based non-shrink grouti. Cement-based QP approved proprietary non-shrink grout shall be used for filling Space under base plates of steel columns and static equipment, and in sleeves around anchor bolts unless noted otherwise.ii. Grout strength shall not be less than the characteristics strength of structural concrete. Epoxy-based non-shrink grouti. Epoxy-based proprietary non-shrink grout shall be used for filling space under base plates and in sleeves around anchor bolts to 'heavy vibrating equipment. Note that 'heavy' vibrating equipment is any equipment of weight greater than 2500kg.Grout strength shall not be less than the characteristics strength of structural concrete. Preparation of non-shrink grouts shall be in accordance with Manufacturers requirements.PREPARATION OF GROUTPreparation of grout shall be in accordance with Manufacturers instructions.Mixing water shall be at a temperature not greater than 27oC.Due regard shall also be taken for the following points: Preparation of grout shall be in a paddle type mortar mixer or by other suitable mechanical mixer. The grout shall not be mixed by hand. Cement, sand aggregate or admixtures shall not be added unless specified by the MANUFACTURER. Use shall be made of the Manufacturers Field Service when undertaking trial sections at the start of a contract.SURFACE PREPARATIONAll surface preparation shall follow the Manufacturers data sheets instructions for each material while implementing the grouting works.The following surface preparation shall apply for all grouts: Concrete foundations shall be at least 7 days old before surface preparation; All laitance shall be removed down to sound concrete; Surfaces to receive grout shall be rough and reasonably levelled; Surfaces shall have been wet-cured or curing compounds shall be removed; The surfaces of concrete and base plate shall be clean; All excess water shall be removed from concrete and bolt holes before grouting, leaving only a damp film; and When epoxy grouts or adhesives are used, keep all surfaces dry before application.FORMWORK FOR GROUTINGFormwork shall be provided for grout and shall be compatible with the method of placing grout, specified hereafter.Forms shall be designed for rapid, continuous and complete filling of space to be grouted. Forms shall be of adequate strength to withstand the fluid grout, and shall be caulked or sealed with tape to provide a watertight seal. The forms shall be coated to prevent grout adherence and absorption.For equipment requiring part of its base to remain ungrouted, such place shall be blocked off with rope, inflated hose or other suitable method. Unless otherwise shown on the drawings, the entire area under the base shall be grouted. The forms shall extend to a minimum of 25mm above the underside of the base plate being grouted and a minimum of 15mm shall be left between the form and the base plate. On the poring side, the forms shall be left a minimum of 50mm away from the base plate. The top of the forms on the pouring side shall be sufficiently high, but no less than 150mm.WEDGES AND SHIM PLATESAdequate wedges and/or shim plates shall be used for levelling steel structures, stationary equipment, prior to grouting, to which the following shall apply: Shims that are used for levelling works shall be of stainless steel to avoid corrosion. Shims under steel structures and equipment shall be of a machined type and need not be removed. Wedges are restricted to minor steel structures, supports, etc. and shall be removed. For shim installation the following criteria shall apply: The shim to be placed on the foundation shall be embedded in a mortar bed such that the top of the shim is levelled; Shim plates shall be installed in such a manner that they are fully embedded and surrounded by the grout to be installed later; minimum cover to shim side: 50mm; and Load per shim pack shall not exceed 7N/mm2 under the worst loading calculating the aforementioned bearing stress.PLACING, CURING AND TESTINGPlacing and curing shall be carried out according to the following: The installation of the grout shall be carefully supervised. Special attention shall be paid to prevent distortion of the item being grouted. Grout shall be mixed adjacent to the area being grouted and sufficient manpower, materials and equipment shall be available for rapid and continuous mixing and placing. The placing of cement based grout mortar shall commence not later than 15 minutes after completion of the mixing. Under no circumstances re-mixing or knocking up shall be allowed. Grout shall not be placed when ambient temperature exceeds 40oC. Vent holes shall be drilled in base plates if required, or as directed by QP Representative. The grout shall fill all voids between the base plate or sole plate and the foundation, shall have full surface contact, be thoroughly compacted and free from air pockets. Any areas or pockets, which have not received grout, shall be sealed with an approved material. Grout may be placed either by pouring or pumping. Grout placed by gravity flow shall be applied continuously under a head not less than 300mm and worked until the space is completely filled. Vibration shall not be used. The grout shall not be overworked. All bolt holes and sleeves shall be adequately filled and pressure grouting used, where directed by QP. Cement-based grout shall be kept moist during the first 7 days after placing and shall be protected from sunshine and drying out by protective covering. All curing compounds shall be approved prior to application. Non-shrink and Epoxy grouts shall be cured in accordance with the Manufacturers instructions. After hardening, wedges shall be removed and the resulting voids shall be filled with grout. Grout shall be extended to the edge of the base plate surface (unless otherwise noted) where it shall be finished with a chamfer of approximately 25mm. Exposed non-shrinkage grout surfaces shall be coated with an epoxy-based product if future contamination with lubricants is possible. Testing for grouts shall be performed as follows: Non-shrink cement based grout shall be tested at least once per day in accordance with ASTM C109. Epoxy grout shall be tested on each pour in accordance with ASTM C579. Prepare the number of cubes for each type of grout and test for required compressive strength according to the following schedule.Grout Type24 Hrs.7 Days28 Days

Non-shrink Cement Grout333

Epoxy Grout333

Where a field service is offered by the MANUFACTURER, this shall be utilized. The Manufacturers guarantees may be dependent on such involvement.Grout shall be cured in accordance with the Manufacturers instructions.FINISHING OF GROUTCement-based grout is to be trimmed back, after the initial set, to the level shown on the drawings with surfaces sloped away from the base plate neatly pointed and trowelled off and left in a workmanlike manner.Exposed edges shall be protected against damage during the curing period.Where shims are to be removed, or if wedges were used, they shall be removed after 3 days. On removal of the shims or wedges, the resultant spaces shall be filled with grout.Epoxy grout cannot be trimmed after set Finish top surfaces prior to initial set per Manufacturers recommendations. Apply finish coating over grout holes and vent holes after grout has set.FORMWORKGENERALFormwork shall be constructed to provide the correct shape, lines and dimensions of the concrete shown on the Drawings. Due allowance shall be made for any deflection which will occur during the placing of concrete within the forms.All Formwork shall comply with BS EN 1992-1-1 and Part 9, Section 5 of QCS. All Formwork shall be water tight to prevent grout loss.Forms shall be constructed form sound materials of sufficient strength, properly braced, strutted and shored to ensure rigidity throughout the placing and-compaction of the concrete without visible deflection. Forms shall be so constructed that they can be removed without shock or vibration to the concrete.Form faces shall be made of marine plywood or steel or GRP.CONTRACTOR shall provide the details and the engineering design of the formwork and shall be responsible for the stability and performance of the formwork. Before concreting, Formwork shall be thoroughly cleaned, then coated with approved Chloride free mould oil. The use of diesel oil is not permitted. Mould oil shall not be allowed to come into contact with concrete already placed or with reinforcement.The Formwork shall be removed in accordance with BS EN 1992-1-1.No forms shall be removed until the concrete has gained sufficient strength to support itself.The striking of formwork shall be as detailed in Part 9, Section 5 of QCS, except the minimum stripping times shall be as follows: i. Vertical sides of beams, walls, columns-24 hrs.ii. Soffit formwork to slabs (props left under)- 7 daysiii. Soffit formwork to beams and props to slabs-14 days iv. Props to beams-21 days v. Cantilever beams and slabs-28 days vi. Slender columns and slender walls-28 days The finished faces of all concrete work shall be sound, solid and free from defects. All corners (except underside of foundation) shall have a 25 x 25 mm chamfer. No rendering of imperfect concrete faces will be allowed and any concrete that is defective in any way (including colour) is to be cut out and replaced to such depths or be made good in such manner as QP may direct.FORM WORK FOR VIBRATED CONCRETEWhere concrete is vibrated in to position, the formwork shall be so designed to withstand the forces from such vibrations. Internal vibrators only shall normally be used. If external vibrators are required to be used, the type of vibrator, design of Formwork and the method of fixing the vibrators shall be all subject to approval of QP. TRANSPORTATION AND PLACEMENTTRANSPORTATIONAll transportation of concrete shall comply with Part 8, Section 5 of QCS. Transportation of mixed concrete from the batch plant to the point of usage shall be by rotating drum agitator trucks, with water tank completely disconnected. Transportation shall be in such a way that the materials do not segregate. PLACEMENTAll placing of concrete shall comply with Part 8, Section 5 of QCS. The target maximum temperature for concrete used in the works is 20 to 25C. However, provided the concrete is manufactured in accordance with Section 4.0 of this document and in particular clause 4.5. Fresh Concrete of a temperature greater than 32C shall not be used. Hot weather concreting shall be done in accordance with Section 6 of BS EN 1992-1-1.The temperature of the concrete at the time of placement shall be measured and recorded for each truck. No concreting shall take place if the temperature in the shade exceeds 43C on a falling thermometer or 40C on a rising thermometer. Concrete shall not be dropped into place from a height exceeding 1.5 meters and shall not be pumped or discharged trough aluminium alloy pipe or equipment. Concrete shall be placed as per sequence shown on the drawing or as indicated in the specification or as approved by QP. Concrete shall only be poured in the presence of QP Representative. In addition, no concrete shall be placed unless QP has previously inspected and approved the positions, fixing and condition of reinforcement, the cleanness, alignment and stability of the formwork.Concrete shall be placed as near as possible to its final position in such a manner to avoid segregation of concrete, displacement of the reinforcement, formwork and/or embedded items.Concrete shall be placed in horizontal layers not exceeding 300 mm thick and continuously between construction joints, the position and arrangement of which shall be predetermined. Where chutes are used to convey concrete, height and slopes shall not be such as to cause segregation at discharge. Preferable slopes shall be 1:2 to 1:3. Conveying equipment shall be cleaned thoroughly before each run. The maximum time period between mixing and placing concrete shall not exceed 30 minutes. The maximum time period between placing successive horizontal layers of concrete shall not exceed 20 minutes.Partially hardened concrete or re-tempered concrete shall not be used in the work. Concrete shall not be placed under water without prior agreement with QP.COMPACTIONGENERALAll concrete shall be fully compacted throughout the full depth to a dense homogeneous mass thoroughly worked against formwork and around reinforcement and other embedded items without displacing them. Successive layers of the same lift shall be thoroughly worked together. When super plasticizers producing a collapsed slump are used, CONTRACTOR must exercise extreme care to ensure the concrete is adequately vibrated but not over vibrated. Over vibration of such concrete can cause segregation. Compaction of concrete shall comply with Part 8, Section 5 of QCS.Unless otherwise directed by QP, approved power driven internal vibrators shall be used at such spacing and applied in such a manner as to ensure uniform compaction without segregation of materials. The power supply to drive the vibrator(s) must be spark free for use in live oil/gas plants. Vibration is not to be applied directly or indirectly to concrete after the initial set has taken place. COMPACTION BY INTERNAL VIBRATORSThe performance of vibrators shall be such as to suit the working conditions and they shall be selected accordingly. For normal use they shall not be more than 75 mm diameter and will be subject to scrutiny by QP. The radius of influence shall be at least 300 mm. The vibrators shall be disposed in such a manner that the whole of the mass under treatment shall be adequately compacted at a speed commensurate with the supply of concrete from the mixtures and to the satisfaction of QP. In small areas, smaller vibrators will be required.Immersion vibrators shall penetrate full depth of the concrete layer. The vibrator shall re-vibrate the upper section of the layer to ensure a full intermix between the concrete layers. Immersion Vibrators shall be slowly withdrawn from the fresh concrete to prevent void formation. No formwork leakage shall be permitted.Vibration of forms shall be avoided and any type of internal vibrator shall not be permitted to come in to contact with reinforcement.Vibration is not to be applied directly or indirectly to concrete after the initial set has taken place.COMPACTION BY EXTERNAL VIBRATORSExternal vibrators shall not be used without the permission of QP. The power supply to drive the vibrator(s) must be spark free etc., for use in live Gas/ Oil plants.TOLERANCEExcept where shown on the drawing or otherwise accepted by QP, the following tolerances, after completion of the works, represent acceptable limits to QP. All work beyond these limits is liable to be rejected by QP.Type of StructureType of IrregularityTolerances(mm)

Foundation and structuresPlan position5

Elevations below ground 10

Elevations above ground 5

Plumb alignment for columns and walls 6 in 3 m 9 in 6 m 12 in 12 m

Dimensions of cross sections 5

Slab thickness 5

Roads and pavingDeparture from line 12

Departure from longitudinal level 6

Departure from transverse cross-section template 6

Deviation from 3.0 m straight edge on longitudinal section 6

Lateral deviation over a 30.00 m straight length. 30

Additional tolerances shall be as specified in Part 9.7, Section 5 of QCS.FINISHESUNFORMED SURFACESUnformed surfaces shall be classified as either: Power float finish U4 - timber trowel finish U3 steel trowel finish U2 brush finished U1 other finish designed in the project documents All unformed surfaces shall comply with the requirements of QCS Section 5, Part 9, Section 9.3 and the following additional requirements: Surface finishing (beyond bull-floating) shall not be commenced until bleed water has disappeared from the concrete surface. CONTRACTOR shall ensure surface finishing is completed before concrete reaches final set. REQUIREMENTS FOR POWER FLOAT FINISHIn addition to the requirements of clause 9.5.1, Power Float Finish shall comply with the following: The completed surface of slabs with power float finish shall have no deviations of greater than 4 mm when measured using a 4 meter straight edge. Power floating must not be started until surface moisture has evaporated and the concrete is stiff enough to take the weight of the machine. Following initial floating to close off and regulate the surface of the concrete, the surface moisture must be allowed to evaporate. Successive passes with the blades set at progressively steeper angles must then be used to produce a closed hard-wearing surface. FORMED SURFACESFormed surfaces shall be classified as either: Class F1 formwork which shall consist of sawn boards, sheet metal or other suitable materials to give good support to the concrete. The irregularities in the finish shall be no greater than those obtained from the use of properly designed forms of closely jointed sawn boards. Small blemishes caused by entrapped air or moisture will be permitted, but the surface shall be free from voids, honeycombing or other large blemishes. Class F2 formwork which shall produce irregularities in the finish shall be no greater than those obtained from the use of wrought thickness square edged boards arranged in a uniform pattern. The finish is intended to be left as struck but imperfections such as fins and surface discoloration shall, if required, be made good by methods approved by QP. Class F3 formwork which shall be lined with a material approved by QP to provide a smooth finish of uniform texture and appearance. This material shall leave no stain on the concrete and shall be so joined and fixed to its backing that it imparts no blemishes. It shall be of the same type and obtained from one source throughout any one structure. CONTRACTOR shall make good any imperfections in the finish as required by QP. Internal ties and embedded metal parts will not be allowed. Class F4 formwork which shall be defined as per Class F3 except that internal ties and embedded metal parts shall be permitted. The ties shall be positioned only in rebates or in other positions as described in the project documents or as agreed by QP. All formed surfaces shall comply with the requirements of QCS Section 5, Part 9 and this Project Specification. CLASS OF FINISH AND MATERIALSAll unformed surfaces shall comply with the requirements of QCS Section 5, Part 9 and the following additional requirements: All Finishes Schedule shall comply with the Project Drawings for the required class of finish on all surfaces (both formed and unformed). Class F1 shall only be used for surfaces against which backfill or further concrete is to be placed or for surfaces covered by additional treatment such as plastering, rendering, brickwork, masonry, tiling etc. or for surfaces not permanently exposed to view. Permanently exposed concrete surfaces to Classes F2, F3 and F4 finish shall be protected from rust marks and stains of all kinds. Unless otherwise described in the project documents, all formwork joints for exposed surfaces of concrete to Class F2, F3 and F4 shall form a regular pattern with horizontal and vertical lines continuous throughout each structure and all construction joints shall coincide with these horizontal or vertical lines. Where Class F2, F3 or F4 finish is specified the use of worn or damaged formwork will not be permitted and care shall be taken not to damage the formwork when being struck or cleaned. The underside of the filler used at horizontal construction joints in walls shall coincide within the joint between two boards. The finish to be applied to concrete adjoining existing concrete / previous pour shall be as per the existing concrete / previous pour unless otherwise instructed by QP. Where a surface is part exposed, part below ground, the above ground finish shall extend to 150mm below finished ground level. Unless otherwise specified, triangular fillets size 20mm x 20mm shall be fixed in the forms so as to provide a chamfer to all external angles in the finished WORK. Chamfers shall be provided even though such chamfers may not be indicated on the drawings. Where grooves are specified in exposed concrete, they shall be formed by attaching tapered planed timber battens accurately aligned to the face of formwork. Where internal ties are used in members with feature groove surfaces, the ties shall be positioned in the groove recesses and shall be in a regular pattern vertically and horizontally. Through bolts shall not be permitted in walls or slabs of water retaining structures or in other elements subject to ground or water pressures. All formwork in contact with concrete shall be treated with a suitable QP approved mould release agent.Care shall be taken to prevent the mould release agent from coming in contact with reinforcement or with concrete at construction joints. Where concrete surfaces are to be exposed or are to have finishes applied, suitable methods shall be used to ensure: adequate mould release, non-staining of concrete surface and full bond for applied finishes. Details shall be submitted to QP for Approval prior to construction of formwork. Where instructed by QP, CONTRACTOR shall cast sample panels to indicate the standard of finish which he intends to maintain. QP shall approve the standard of finish before any permanent concrete WORK is undertaken. Before the commencement of concreting, all foreign material shall be removed from the interior of the formwork and the inside of the formwork shall be thoroughly clean and free from sawdust, mud or other debris. Where steel shutters are used, all joints and holes in the shutters shall be covered with tape, which shall be firmly fixed to the shutters by means of spirit glue or other oil and grease resisting adhesive. Where internal metal ties are permitted, they or their removable parts shall be extracted without damage to the concrete and the remaining holes filled with non-shrink mortar. No permanently metal part shall have less than 75mm cover to the reinforcement. All floors in electrical rooms and switch rooms shall have finish U3 and QP approved epoxy coating specifically designed for electrical / substation applications. Unless noted otherwise in the project drawings and specifications, concrete finishes shall be in accordance with the following table: CONCRETE FINISHESElementUnformed SurfacesFormed Surfaces

All formed concrete surfaces (unless noted otherwise)U3F2

Wetted surfaces of water retaining structures Exposed concrete walls and columns (without plaster)F3

Transformer pits and cable trenches U3

Internal floors in buildings where the finished surface is to be stonework or ceramic tiles, laid on a mortar bed.U4F2

Roofs of buildings (surface of structural slab, below screed, waterproof membrane, etc.)U4

Concrete and screed surfaces where paint or waterproof membrane is to be appliedU3

Internal floors in buildings where the finished surface is to be vinyl, carpet, epoxy, paint or exposed concrete (unless noted otherwise)U3

Surfaces of external concrete pavements.U2

Surfaces of concrete slabs in covered car parking areas (if no additional finishes are to be applied)U2

Top surfaces of equipment foundations and plinths for steel structure (to be grouted)U2

CURINGAll curing of concrete shall comply with Part 10, Section 5 of QCS. The Curing of concrete shall proceed for a minimum period of seven days. Surfaces shall be treated as follows:HORIZONTAL SURFACESHorizontal surfaces shall be wet cured and treated with curing compound as soon as the concrete has taken its initial set. The surface shall then be bundled and flooded with water or draped with wet hessian, covered with two layers of 500 gauge (0.125mm) white polythene sheeting and kept continuously wet for the length of the curing period. Water used for curing shall be at the same temperature as the concrete being used.VERTICAL SURFACESVertical surfaces shall be treated with curing compound as soon as the formwork is removed. The surfaces shall be draped with wet hessian, covered with two layers of 500 gauge (0.125mm) white polythene sheeting and kept continuously wet for the length of the curing period as agreed with QP. Care should be taken to avoid drying winds with a wind tunnel arrangement of the coverings.CURING COMPOUNDThe curing compound shall have an efficiency of 85 % as defined in accordance with clause 2709 of British Department of Transport Specification for road and Bridge works and shall be white or silver coloured to reflect the sun rays.Fog spray for wetting surfaces shall be used whenever practical.In addition to the above requirements, CONTRACTOR shall comply with the requirement as set forth in Part 10, Section 5 of QCS.

REMEDIAL WORKConcrete exposed by the removal of formwork shall be inspected by QP before any remedial work; subsequent coating or any other treatment which would hinder the proper inspection of the concrete is carried out. Any concrete, the surface of which has been treated prior to being inspected by QP shall be liable for rejection.Concrete which in the opinion of QP is defective or which is not true to an acceptable line or level, shall be cut out and rebuild without delay, unless QP agrees that a repair may be satisfactorily effected. This agreement shall not produce the subsequent rejection of the repaired work.The methods to be used in removal and replacement or repair of defective work shall be submitted to QP for approval in each particular case before the work commences.READYMIX CONCRETEReady mix concrete from an approved supplier shall be used with the approval of QP. The concrete shall comply in all respects, with BS EN 206 and Part 7, Section 5 of QCS and with this Project Specification.Only with the specific written approval of QP concrete may be transported in a dry state and water added on site. Care shall be taken to ensure that the correct quantity of water is added to the mixer.Before discharging the concrete at the point of delivery, for each batch of concrete, the CONTRACTOR shall provide QP with a delivery ticket on which is printed, stamped or written the following minimum information. Name of concrete Depot; Serial Number for ticket; Date; Truck number; Name of the supplier; Grade or mix description of concrete; Type of cement; Cement content; Water/cement ratio; Nominal maximum size of aggregates ; Source of aggregates; Type or name of admixture, if included; and Quantity of concrete in cubic meter.PROTECTIVE COATINGSGENERALAll concrete shall be investigated for surface holes and provided they are small and formed by air bubbles caught against formwork they shall be filled with filler compatible with the coating to be applied, if that coating cannot bridge the holes. For surface holes having any dimension greater than 20 mm, refer to section 11 of this specification.CASTING ONTO SOILConcrete shall be cast onto a layer of waterproof membrane or approved equivalent laid over concrete blinding. Overlap of membrane shall be 75 mm.Cement mortar screed, grade C15, of at least 40mm thick shall be provided over the membrane to act as protection of membrane on horizontal surfaces and slope not exceeding 45.Concrete for floor slabs, ramps and paving shall be cast against 1000 gauge (0.25mm) polythene sheet membrane on a well compacted formation. Minimum lap of the membrane shall be 300mm. Laps shall be sealed with tape full length.SURFACE BELOW SOILReinforced concrete in contact with soil in foundations shall be protected using minimum 1.5mm thick self-adhesive waterproof membrane. Membrane shall be specifically formulated for hot climates, shall have proven performance in the Middle East and shall incorporate a contrasting colour reflective external film. Membrane shall withstand a minimum static head of 60m of water and shall comply with the tear resistance, adhesion, puncture resistance, and moisture vapour transmission rate specified in QCS Section 5, Part 14, Table 14.1. Suitable membranes include bituthene 8000 HC membrane system produced by grace construction products, or QP approved equivalent.For surfaces not exceeding 45 to the horizontal, the bituthene or equivalent membrane is to be laid on top of concrete blinding. Minimum thickness of concrete blinding shall be 75mm.The top surface of the membrane is to be protected with a cement screed grade C15 (SRC) at least 40 mm thick.For surfaces/slopes exceeding 45 to the horizontal, the bituthene or equivalent membrane is to be protected using SERVIPAK bitumen impregnated hardboard or equivalent at least 6mm thick, suitably boned to the membrane. Minimum thickness of protection board shall generally be 6mm, except that protection boards thinner than 6mm, with proven performance on similar projects in the Middle East, may be submitted for QP review.At junctions and joints the membrane is to be overlapped by a minimum of 75mm. Exposed edges of concrete are to be chamfered, proprietary angle beads are to be provided where necessary. Where rising block-work walls are supported by concrete foundations, cement screed minimum 10mm thick shall be applied to the surfaces of block-work to provide a smooth surface for membrane installation. Any irregularity which might cause the membrane to be punctured shall be removed. The membrane and protection board shall be applied on each side of the rising wall up to ground level. Where a floor slab abuts the rising wall, the membrane shall be overlapped by the slab polythene damp proof membrane. All edges shall be chamfered and proprietary corner fillets shall be installed. Manufacturers recommendation shall be strictly adhered when applying the protection system. All waterproofing products shall be from the same manufacturer and shall be fully compatible. All waterproofing products shall be subject to QP approval. A QP approved protective coating and protection board / 1000 polythene wrapping shall be applied to all pre-cast concrete surfaces which are not otherwise protected with suitable membrane, before installation.ABOVE GRADE CONCRETE PROTECTIONThe protective coating materials shall be from QP approved manufacturers / vendors and the application of coating shall be as per the manufacturers written instructions. The following areas shall be coated with penetrating silane-siloxane primer and subsequent pigmented coating of minimum total dry film thickness (DFT) 150 microns (0.15mm) applied in three (3) coats: All internal surfaces (top, bottom and sides) of reinforced concrete culvert structures. All exposed concrete in bridge superstructures and substructures. Above ground surfaces of foundation plinths supporting mechanical equipment and vessels Pre-cast concrete pipeline sleepers. Other areas as specified in the project drawings. PRIMERThe first coat shall be a penetrating silane-siloxane hydrophobic primer applied as a flood coat at a rate of 0.4 litre per m2. The silane-siloxane primer shall have no less than 10% solid contents. INTERMEDIATE COATThe second coat shall be an acrylic polymer coating system applied to a DFT of minimum 75 microns. FINISH COATA third coat of acrylic polymer coating system shall be applied to a DFT of minimum 75 microns. The total DFT of the coating system (all layers) shall be minimum 150 microns. The acrylic polymer shall have the following minimum properties: Solid content 70% Chloride ion diffusion 3.63 x 10-10cm2/s Moisture Vapour Transmission 45g/m2/24 hour Reduction in chloride ion penetration 97% Application trials shall be carried out on selected coating as directed by QP. PRE-CAST CONCRETESubject to the approval of the QP, the CONTRACTOR may arrange for portions of the work to be pre-cast.All pre-cast concrete works shall be in Grade C40.All pre-cast concrete shall be manufactured under the direct supervision of the CONTRACTOR and to approval of QP. The manufacture shall comply with BS EN 1992-1-1.All pre-cast concrete to be used shall comply with Part 17, Section 5 of QCS-2007.Surfaces of pre-cast concrete required to make structural connections with in-situ concrete shall be prepared in accordance with BS EN 1992-1-1.The moulds shall be purpose-made to produce the required finish as described on the drawings. Reinforcement shall be in accordance with the requirements of the specification. No items shall be lifted from the casting beds until it has attained sufficient strength to avoid damage through lifting, handling, erection or stacking. Any items damaged will be rejected by the QP and must be disposed of and replaced at the Contractors expense.All pre-cast items shall be subject to testing procedures as described in this specification.THIRD PARTY INSPECTIONQP shall have the right to call an approved Third Party at any time for inspection of the works. Cost will be borne by the CONTRACTOR.

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