Concrete and Reinforced Concrete Work in Foundations, Structures, Buildings, and Roads

Table of Contents

Title

Purpose

Scope

3.1 British Standards Institute (BSI)

BS 12 Portland cement

BS 146 Portland blastfurnace cements

BS 812-101 Testing aggregates: Guide to sampling and testing aggregates

BS 882 Aggregates from natural sources for concrete

BS 915-2 High alumina cement: Metric units

BS 1370 Low heat Portland cement

BS 1881 All parts Testing concrete

BS 3148 Methods of test for water for making concrete

BS 4027 Sulphate-resisting Portland cement

BS 4248 Supersulphated cement

BS 4449 Carbon steel bars for the reinforcement of concrete

BS 4482 Cold reduced steel wire for the reinforcement of concrete

BS 4483 Steel fabric for the reinforcement of concrete

BS 5075 Concrete admixtures

BS 5328-2 Concrete: Methods for specifying concrete mixes

BS 8007 Code of practice for design of concrete structures for retaining aqueous liquids

BS 8110 Structural use of concrete

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

Note: These documents are applicable when Appendix A is being referenced.

3.2 Centre Scientifique et Technique du Batiment (CSTB)

DTU 21 Execution of works in concrete

Note: This document is applicable when Appendix C is being referenced.

3.3 L’Association Francaise de Normalisation (AFNOR)

XP P18-305 Concretes – Ready mixed concretes prepared in the factory

Note: This document is applicable when Appendix C is being referenced.

3.4 Nederlands Normalisatie-Instituut (NNI)

NEN 6700 General Principles

NEN 6702 Loadings and Deformations

NEN 6720 Regulations for Concrete Structural Requirements and Calculation Methods

Note: These documents are applicable when Appendix B is being referenced.

3.5 All workmanship and materials shall be according to the project specification, drawings, this specification, and, except where otherwise specified, the latest edition of the documents listed in the Related Documents Section. In any case, all workmanship and materials shall be according to the latest National standards of the country in which construction takes place.

CONCRETE MATERIALS

4.1 Cement

4.1.1 Cement Types: All cement, unless otherwise specified, shall be ordinary Portland cement. Other cement shall not be used without prior approval from the engineer. The concentration of alkalis present in cement shall not exceed 0.6% of Sodium Oxide Na20 content.

4.1.2 Different types of cement shall be stored separately. Bagged cement shall be stored in a damp-proof building with a raised floor. Bulk cement shall be stored in a hopper designed for the purpose, but not for longer than six weeks. Lumpy cement, partly set cement, mixed cement, or cement stored for more than six weeks shall not be used for construction, but shall be removed from the site by the contractor.

4.2 Aggregate

4.2.1 Aggregate shall be delivered and stored on site in a clean condition and in such a way that different aggregates cannot be mixed. The engineer may reject aggregates that do not comply with these requirements and, if so, they shall be removed from the site.

4.3 Water

4.3.1 Water requirements shall comply with the relevant National standard.

4.4 Additives and Admixtures

4.4.1 General: Additives or admixtures are not permitted without the approval of the engineer. Chlorides or additives containing chlorides shall not be used.

4.5 Air Entrainment

4.5.1 Air entrainment mixtures shall be according to the following:

4.5.1.1 All road slabs, pavings, and walls exposed to atmospheric conditions: 4% to 6% (by volume) of entrained air to increase the resistance to freezing, thawing, and penetration of water.

4.5.1.2 Elsewhere: 2% to 4% (by volume) of entrained air to increase workability.

4.5.2 The contractor shall carry out tests on site using an approved volumetric air meter. The rate of sampling shall be as required for test specimens in paragraph 5.2.

Concrete Quality

5.1 Production, Batching, and Mixing

5.1.1 The solid constituents of the concrete mix shall be measured by weight.

5.1.2 All concrete shall be mixed in a mixer of approved design and maintained in good order.

5.2 Sampling and Testing

5.2.1 General: Sampling and testing of specimens shall be carried out on all concrete by an independent testing authority approved by the engineer. All costs of sampling, testing, and transportation shall be borne by the contractor.

5.2.2 Test Equipment: Before concreting begins, the contractor shall have on site adequate testing equipment including a volumetric air meter, thermometer, slump cones, and sufficient moulds to take 50% more test specimens than the day’s concreting requires.

5.2.3 Sampling

5.2.3.1 Samples shall be taken for testing cubes or cylinders, slump, and when necessary, temperature randomly from every 20 m3 of concrete, or each day’s pour, if less than 20 m3. This applies to each grade of concrete used.

5.2.3.2 Additional samples shall be taken to quickly establish the concrete quality when:

a concrete is used for the first time, or

using a concrete class for the first time, or

concrete is supplied from a different source or produced from different materials, or

the engineer’s representative has a reason to doubt the concrete quality.

Note: The rate of sampling in these situations shall be not less than one sample from every 5 m3 of concrete.

5.2.3.3 Samples shall be taken at the place of discharge from the mixer or delivery vehicle.

5.2.4 Tests for the Assessment of Strength

5.2.4.1 Two test specimens shall be prepared from each sample. Every test specimen shall be dated the day it was made, numbered consecutively, and recorded for 28-day testing. Both specimens shall be tested at 28 days.

5.2.4.2 The average of the two results shall be taken as the strength test result.

5.2.5 Tests for Determination of the Temperature of Fresh Concrete

5.2.5.1 When concreting in hot or cold weather, tests shall be made from each sample as follows:

Within 2 minutes of taking the sample, a 100 mm concrete immersion thermometer having a range of -5°C to +100°C, graduated at 1°C, shall be inserted in the sample to a depth of at least 100 mm. When steady conditions have been maintained for 1 minute, the temperature shall be recorded to the nearest 1°C.

5.2.6 Tests for Workability: Slump tests shall be taken from each sample and when directed by the engineer.

5.3 Compliance

5.3.1 Compliance with Characteristic Strength shall be assumed if the following conditions are met:

The average strength determined from any group of four consecutive test results exceeds the specified characteristic strength by 3 N/mm2 for concretes of 20 N/mm2 and above, and 2 N/mm2 for concretes below 20 N/mm2, and

The strength determined from any test result is not less than the specified characteristic strength minus: 3 N/mm2 for concretes of 20 N/mm2 and above, and 2 N/mm2 for concretes below 20 N/mm2.

Note: For small concreting operations, when the total test results are less than four, the strength determined from every test result shall exceed the characteristic strength by 3 N/mm2.

5.3.2 Compliance with Workability: The workability requirement may be assumed to be satisfied if the results of the slump tests comply with the required performances.

5.3.3 Compliance with Temperature: When the temperature of the concrete is outside the requirements for concreting in hot or cold weather, it is not in compliance.

5.4 Quantity of Concrete Represented by Test Results

5.4.1 The quantity of concrete represented by any group of four consecutive cube test results shall include the batches from which the first and last samples were taken together with all intervening batches. For small concreting operations, a test result that fails to comply with the note in paragraph 5.3.1, only the particular batch from which the sample was taken shall be at risk.

5.4.2 The quantity of concrete represented by the workability or temperature tests shall include the batch represented by the sample or the unit of construction as defined by the engineer.

5.5 Records

5.5.1 For every batch of concrete and every test, records shall be made.

5.5.1.1 Records of batches shall state the following:

Consecutive number of batch

Size of batch

Classification

Cement content per m3

Position of the batch within the works

Date of placing

Number of test specimens made

Results of tests for strength

Source of concrete, name, and address of supplier

Result of workability test

Result of test for temperature

5.5.2 Copies of test results together with the batch records shall be sent as follows:

Two copies to the engineer’s representative.

One copy to: Air Products PLC

Design Department, Civil Engineering Section

Hersham Place

Molesey Road

Walton-on-Thames

Surrey KT12 4RZ

5.6 Action to be Taken in Event of Noncompliance

5.6.1 If any part of the work does not comply, the engineer shall be notified.

5.6.2 Any concrete that is placed for which subsequent tests do not comply, or any of the work that is found not to comply for any reason, will be referred by the engineer to the Air Products Design Department, Civil Engineering Section, Hersham for their examination and comment.

5.6.3 The engineer may subsequently reject all of the concrete represented, in which case, the contractor shall break out the affected parts, remove them from site, and replace or undertake other remedial work as determined by the engineer.

5.7 Additional Tests on Concrete for Seven Day Testing: When the engineer requires the seven day strength, the contractor shall obtain an assessment of strength according to this specification, except that specimens shall be cured for, and tested at, seven days. These extra tests shall be identified at the time of making and shall not be used for the normal quality control or compliance procedure.

Reinforcement

6.1 Cleanliness: All reinforcement shall be free from loose rust, oil, grease, dirt, or ice. When stored on site, it shall be kept clear of the ground and adequately supported to prevent deformation.

6.2 Fabrication and Labelling: Reinforcing bars shall be fabricated according to relevant standard, and every bar shall be labelled with its scheduled mark number, schedule number, and drawing number. No welding is permitted without prior approval from the engineer. No bar shall be rebent or straightened.

6.3 Fixing

6.3.1 The reinforcement shall be assembled and fixed rigidly within the forms to prevent movement during placing and vibration of the concrete. No metal shall come into contact with the concrete surface.

6.3.2 Cover shall be maintained with concrete or plastic blocks and chairs. If necessary, the contractor shall provide steel chairs, spacer bars, and supporting steelwork not shown on the drawings to satisfy this requirement. Soft iron wire bindings shall be used at intersections of bars.

6.4 Material Quality: The equivalent carbon content shall not exceed 0.51%. The contractor shall obtain from the supplier for each consignment, a certificate of reinforcement quality confirming compliance to the relevant standard, and of manufacturing to a relevant quality assurance procedure approved by the National Standards Organisation.

Formwork

7.1 Design and Construction: Forms shall be designed and constructed to withstand transporting, placing, and vibrating operations without leakage of concrete or deviation from line. Sufficient labour shall be in attendance during concreting operations to constantly check and maintain the work.

7.2 Exposed Corners: Exposed corners of concrete not abutting with concrete, grouting, brickwork, or steelwork, shall be provided with chamfers 25 mm wide (measured across the face of the chamfers).

7.3 Ties: No ties shall be used that cannot wholly or partly be removed, so that there is no metal surface within 20 mm of the concrete surface. No ties are permitted to remain in water retaining structure.

7.4 Cleaning and Inspection: Temporary openings shall be provided at the base of walls and columns to facilitate cleaning and inspection of the forms. These shall be free from all foreign matter, including ice and snow, and shall be inspected before placing the concrete.

7.5 Release Agent: All formwork shall be coated with a nonstaining mineral oil or proprietary release agent before the reinforcement is fixed.

7.6 Templates for Bolts: When six or more bolts are required for any item of equipment in a single group, the contractor shall provide and use a prefabricated template to hold the bolts rigidly and accurately in position. The template shall be checked and approved by the engineer’s representative before installation.

Tolerance

8.1 Dimensions of, or to, finished concrete shall have tolerances not greater than those given below. Tolerances apply to the final calculated position and are not cumulative on each dimension. Special tolerances where required will be specified on drawings.

For work below ground, the distance to unit setting out lines and levels from plant setting out points + 25 mm
For work above ground, the distance to unit setting out lines and levels from plant setting out points + 12 mm
Dimensions of units of concrete below and above ground from unit setting out lines and levels

Up to 1.0 m + 5 mm

1.0 m to 3.0 m + 15 mm ) except where the bullet below

Over 3.0 m and + 25 mm ) below gives a

foundation bearing surfaces ) tolerance

Level of top surface of foundations to receiv equipment:
Between any two points on the surface + 12 mm
Within 10 m, the difference in level of any two points shall not exceed + 6 mm
Variation in flatness of other surfaces, horizontally or inclined, shall not exceed 5 mm from a 3 m straight edge
Bolt locations from setting out lines and levels + 6 mm

Transporting and Placing

9.1 The contractor shall give the engineer’s representative 24 hours notice before placing concrete. Concreting shall not proceed until the condition of the forms, reinforcement, water bars, and other embedded items are approved. All methods of transporting and placing concrete are subject to approval and shall ensure that segregation and loss of ingredients does not occur. Concrete shall be deposited in the forms of horizontal layers as near as possible to the final position. Concrete shall not be dropped with a free fall greater than 1500 mm. If necessary, openings in the formwork shall be provided to facilitate this. If chutes are used, they shall be steel lines and regularly cleaned and flushed away outside the formwork.

9.2 Concrete shall be deposited continuously and as rapidly as possible until the unit under construction has been completed. In slabs and walls, the full thickness shall be completed in one operation. If the volume of concrete is such that it is impractical to pour continuously, then construction joints shall be introduced (see paragraph 13).

9.3 Placing of concrete after daylight hours is not permitted unless adequate lighting is provided and permission is obtained from the engineer’s representative.

Compaction

10.1 Concrete shall be thoroughly compacted with an internal mechanical vibrator within 15 minutes of placing. Vibration shall be capable of affecting concrete within 500 mm radius and shall be used to release all trapped air, without causing segregation of the aggregate. Platform or screed-type vibrators may be used to ensure a dense top surface when it is impractical to use internal equipment.

10.2 The vibration period shall be calculated at the rate of 3 min/m2 area of layer being placed. Platform-type vibrators shall be operated only long enough to imbed the aggregate.

10.3 Particular care shall be taken when placing and compacting concrete around water bars located at concrete joints, to ensure that the bars are not displaced or damaged leading to subsequent leaking at the joints. The water bars shall be fixed and the ends jointed together according to the manufacturer’s recommendations (see paragraph 13).

Curing and Protection After Placing

11.1 Curing

11.1.1 After placing, and as soon as the concrete has set, the concrete shall then be prevented from losing its moisture for seven consecutive days.

11.1.2 This period of seven days may be conditionally reduced as follows to:

Four days if concrete temperature is above 10°C.

Two days if concrete temperature is above 10°C, the maximum air temperature is below 20°C, and there is no drying wind.

11.1.3 Moisture loss shall be prevented by covering with an absorbent material and constantly wetting, or by covering with an impervious membrane after thoroughly wetting. The absorbent material may consist of canvas, hessian, strawmats, or a layer of sand.

11.1.4 The impervious membrane may be waterproof paper or polyvinyl chloride (PVC) sheet maintained in contact with the concrete and in turn, protected and maintained. Alternatively, unless the surface is to be subsequently bonded, specially designed liquid curing membrane applied according to the manufacturer’s instruction may be used.

11.1.5 If forms are removed within the period described in paragraph 11.1, exposed surfaces shall be maintained in a moist condition by one of the methods listed in paragraph 11.1.

11.2 Protection: After placing, and whilst hardening, the concrete shall be adequately protected from hot sun, drying winds, cold, wet weather, traffic, and any cause that would affect the final work. When a liquid curing membrane is used, the surface shall be protected from use and all traffic shall be kept from the surface for 48 hours. If any damage occurs to the membrane, it shall be repaired by applying two coats of membrane.

11.3 Removal of Forms

11.3.1 Unless specified in the relevant code of practice of standard, formwork shall not be removed in less time than is specified in the Table 1. Should the minimum daily temperature fall below 2°C, the time shall be increased by one day for each day that this occurs. When the times given are less than seven days, adequate provision must be made for curing (see paragraph 11.1).

11.3.2 In no case shall the formwork be stripped until the concrete can support twice the load to which it will be finally exposed.

Table 1 – Striking Times for Formwork After Pouring

Note: For minimum daily air temperatures below 2°C, striking times for 2 to 7°C shall apply in addition to the requirements for cold weather concreting.

Finishes

12.1 General

12.1.1 After the removal of formwork, the contractor shall not apply any surface treatment or finishes until the surface has been inspected by the engineer’s representative.

12.1.2 When the engineer’s representative orders patching or breaking out and making good, such work shall be done to the satisfaction of the engineer’s representative and at the contractor’s expense.

12.2 Finishes from Formwork or Moulds

12.2.1 Type FA finish: The surfaces may be imprinted with the grain of sawn boards and their joints. In addition, small blemishes caused by entrapped air or water may be expected, but the surface shall be free from voids, honeycombing, or other large blemishes.

12.2.2 Type FB finish: The surface may be imprinted with the slight grain of wrought boards and their joints. Alternatively, steel or other suitable material may be used for the forms. Small blemishes caused by entrapped air or water may be expected, but the surface shall be free from voids, honeycombing, or other large blemishes.

12.2.3 Type FC finish: The surfaces shall be hard and smooth with clean arrises as is obtained by using properly constructed and designed plywood forms. Only very minor surface blemishes shall occur and there shall be no staining or discolouration.

12.2.4 Type FD finish: This finish is obtained by first producing a Type FB finish. The surface is then improved by carefully removing all fins and other projections, thorough washing down, and then filling the most noticeable surface blemishes with a cement and fine aggregate paste to match the colour of concrete. Care shall be taken to ensure that the finished concrete surface is not permanently stained or discoloured.

12.2.5 Type FE finish: This finish is obtained by first producing a Type FC finish and then, while the concrete is still green, (i.e., within three days of placing) filling all surface blemishes with a fresh, specially prepared cement and a fine aggregate paste to match the colour of the concrete. After the unit has been properly cured, the faces shall be rubbed down where necessary, to produce a smooth and even surface.

12.3 Finishes to Horizontal Surfaces

12.3.1 Type TA finish: This finish shall have a surface floated with a wooden board and may have small ridges left by the float. In addition, small blemishes caused by entrapped air or water may be expected, but the surface shall be free from voids, honeycombing, or other large blemishes.

12.3.2 Type TB finish: This finish shall be achieved using a specially designed, hard, smooth wooden float. The surface shall be smooth with true, clean arrises. Only very minor surface blemishes shall occur and there shall be no staining or discolouration.

12.3.3 Type TC finish: This finish is obtained by first producing type TB finish. While concrete is still green (i.e., within three days of placing), fill all surface blemishes with a fresh specially prepared cement and fine aggregate paste to match the colour of the concrete. After the unit has been properly cured, the surface shall be rubbed down where necessary to produce a smooth even surface.

12.4 Special Finishes

12.4.1 Special finishes are required for grouting, painting in buildings, roads, and footpaths. See separate applicable specifications.

12.4.2 Surfaces of slabs forming the floor of buildings, where no screed is to be applied, shall be finished with a steel trowel and treated with a dustproofing agent. When screed is to be added, the slab surface shall have a tamped finish by screed board.

12.5 Finishes at Joints: At construction joints, exposed adjacent faces shown on drawings to be in the same plane shall be flush with one another. However, if this is not achieved and the projection between faces exceeds 2 mm, the projecting face shall be ground down as necessary to the satisfaction of the engineer’s representative.

12.6 Required Finishes: Unless otherwise required by the drawings or by paragraph 12.4, finishes to be used shall be of no lower quality than specified in Table 2.

Table 2 – Types of Finishes

Location	Formwork	Top Surface
Unexposed (such as against earthfaces)	FA or FB	TA
Foundation surfaces exposed to view and internal surfaces of cooling water ponds or other surfaces concealed by water	FC	TB
Exposed surfaces and surfaces of walls and elevated concrete surfaces	FD	TB
Exposed to view inside buildings	FE	TC

Joints and Bonding of Concrete

13.1 When the contractor proposes to use joints additional to those shown on the drawings, these shall be approved by the engineer in the Civil Engineering Department.

13.2 The contractor shall plan concrete placing operations so that concreting may be carried out continuously without any break between construction joints. The construction joint shall be roughened with a hammer such that 50% of the area shows coarse aggregate, and then cleared of all laitance and foreign matter. Immediately before placing, the surface shall be saturated with water. If concreting of walls or floors is interrupted for a period greater than one hour, the contractor shall introduce a stop board for the full depth of the lift.

13.3 Expansion and contraction joints shall be constructed according to the details and the locations, which are shown on the drawings.

13.4 The contractor shall use water bars of a type approved by the engineer at all construction joints in water-retaining structures.

Special Requirements for Ready-Mixed Concrete

14.1 General: Concrete delivered to site ready-mixed shall be obtained only from approved suppliers and shall be according to the relevant standard.

14.2 Equipment: Concrete shall not be transported in nonagitating equipment.

14.3 Time of Depositing and Delivery Note: Concrete shall be deposited in the forms within two hours of the introduction of the cement to the mixer. The delivery note shall state the information as specified in paragraph 14.4.1. Concrete not placed in the forms within the specified time shall be rejected.

14.4 Records Kept at Site: It is essential that a permanent record is maintained on site providing the following information, in addition to that information required in paragraph 5.5.

14.4.1 For each lorry:

Depot from which concrete was mixed and supplied.

Registration number of lorry.

Time of introduction of cement to mixer.

Time of arrival of lorry.

Time of pour.

Concreting in Cold Climate and Cold Weather

15.1 Air Temperature: Concreting is not permitted after the minimum daily air temperature falls below 3°C on a falling thermometer or before it reaches 2C on a rising thermometer, unless special precautions are taken as outlined in paragraphs 15.2 to 15.6.

15.2 Temperature of Concrete at Mixing and Placing: The temperature of the concrete at the time it is placed shall be at least 10°C, but mixed concrete temperature shall never be allowed to exceed 30°C.

15.3 Preparation: Special approved supplementary equipment shall be in readiness on the site not less than 24 hours before placing. Before depositing concrete on any surface, all snow and ice shall be removed. Excavations shall be protected from freezing with straw matting or other insulating material. Concreting into frozen ground or the use of materials containing ice is not permitted.

15.4 Protection: In addition to the protection required by paragraph 11.2, effective means shall be provided for maintaining the concrete surfaces at a minimum of 20°C for not less than three days or at not less than 10°C for five days, but never greater than 30°C. The concrete shall be kept above freezing temperature for at least seven days. Particular care shall be taken to maintain the concrete in a moist condition for seven days after placing, and to ensure that insulating material is not placed so that it absorbs moisture from the concrete. For seven days after placing, the temperature of strategic parts of the structure shall be recorded twice daily.

15.5 Use of Chemicals: No salt or chemical shall be used to lower the freezing point, to accelerate the setting, or as a substitute for the specified curing and protection.

15.6 Damage by Frost: All concrete damaged by frost shall be removed and replaced by the contractor.

Concreting in Hot Climate and Hot Weather

16.1 Maximum Temperature: Provision shall be made to ensure that at no time does the temperature of the concrete exceed 30°C.

16.2 Protection and Preparation: To avoid premature stiffening, concrete shall not be placed in contact with hot dry surfaces. Such surfaces shall be shielded from the sun and sprayed with water to prevent local drying and/or absorption of moisture. Fine spraying of the concrete during placing might be required.

Placing Concrete under Water

17.1 Special Requirements: Placing of concrete under water shall be done under the immediate supervision of the engineer’s representative. The minimum content of cement used shall be 400 kg/cm3 of concrete. It is essential that concrete is placed either by using a tremie or bottom opening watertight bucket.

17.2 Tremie: The tremie diameter shall not be less than 250 mm and it shall be watertight. It shall be free moving and capable of concreting continuously over the whole area. The discharge end shall be completely submerged in the concrete at all times. Concrete with slump test results of 125 to 150 mm is acceptable.

17.3 Bucket: The bucket shall have a minimum capacity of 0.4 m3. It shall not be opened until it rests against previously placed concrete and shall be removed with minimum disturbance. Concrete shall not be placed in running or agitated water. Acceptable slump test limits for the concrete are listed in the Appendixes 1, 2, and 3.

Testing for Watertightness of Concrete for Water-Retaining Structures

18.1 General: All concrete water-retaining structures shall be tested. Testing shall be carried out as soon as possible after the expiry of 28 days from the date of placing concrete, but before backfilling. Any leakage detected shall, if required by the engineer’s representative, be made good and the structure tested again all to the satisfaction of the engineer. If any further leakage occurs, the procedure shall be repeated until leakage ceases.

18.2 Method: The structure shall be filled with water to the maximum working level and maintained at this level for seven days. During a further seven day test period, daily recordings of the water level shall be taken by the contractor in the presence of the engineer’s representative.

18.3 Performance

18.3.1 If any leakage is detected by the recordings after allowance for absorption, precipitation, and evaporation, or if exposed surfaces of the structure are wet and show signs of leakage, the test may be extended for a further seven days. If leakage persists, remedial measures, approved by the engineer, shall be taken by the contractor and the structure shall be tested again. If leakage reoccurs, the repair and test sequence shall be repeated until leakage ceases.

18.3.2 The recordings may be regarded as satisfactory if, after noting throughout the test period the atmospheric conditions and making due allowance, the total drop in level is not more than 10 mm in seven days.

18.4 Remedial Measures: Remedial measures might include pressure grouting, application of waterproof render linings, patching, or breaking out and reconstructing, or any combination of these measures.

18.5 Cost: The full cost of the testing and remedial works shall be borne by the contrac

Appendix A UK Requirements

A.1 Reinforcement Quality

A.1.1 Specified Reinforcement

Symbol	Description	BS	Grade	Characteristic Strength (N/mm2)	Bond Class Type
R	Plain Round	4449	250	250	N.A
T	Deformed High Yield	4449	460	460	Type 2
Note: Fabric reinforcement shall be to BS 4483.

A.1.2 Reinforcement to be Used

A.1.2.1 Unless otherwise required by the drawings, all steel shall be deformed hot rolled high yield according to BS 4449, type 2.

A.1.3 Quality

A.1.3.1 The equivalent carbon content shall not exceed 0.51%.

A.1.3.2 The contractor shall obtain from the manufacturer or supplier a certificate of reinforcement quality, or compliance to the relevant standard and of manufacture to a relevant quality assurance procedure according to the relevant standard.

A.1.3.3 The certificate shall permit the history and performance of the steel to be ascertained.

A.1.3.4 In the UK, the supplier shall hold a CARES certificate of approval.

Note: See paragraph 3.1 for other applicable related documents.

A.2 Concrete Quality

A.2.1 Classification and Performance: Concrete shall meet the performance specified below for the class specified:

Reinforced Concrete Class’n	Maximum Aggregate Size (mm)	Characteristic 28 day strength (N/mm2)	7 day strength	Minimum Cement Content	Workability Slump (mm)
C30	20	30	20	290 kg/m3	12 – 100
C25	20	25	16.5	290 kg/m3	12 – 100
C20	40	20	13.5	260 kg/m3	12 – 125
C20	20	20	13.5	290 kg/m3	12 – 100
C20	10	20	13.5	340 kg/m3	0 – 50

Plain Concrete Class’n	Maximum Aggregate Size (mm)	Characteristic 28 day strength (N/mm2)	Minimum Cement Content
C20	20	20	220 kg/m3
C20	40	20	220 kg/m3
C20	20	10	150 kg/m3
C20	40	10	150 kg/m3

A.2.2 Concrete to be Used

A.2.2.1 Unless otherwise stated on the drawings, all concrete shall be Class C30 except as follows:

Aggregate for water-retaining structures and roads shall have a low drying shrinkage and an absorption as measured according to the relevant standard, generally not greater than 3%.

Appendix B – NL Requirements

B.1 Reinforcement Quality

B.1.1 All reinforcement shall be FeB 500.

B.1.2 Quality: In the Netherlands, the supplier shall hold KOMO quality certificate of approval.

B.2 Concrete Quality

B.2.1 Classification and Performance: Concrete shall meet the performance specified below for the grade specified:

Reinforced Concrete Class’n

Maximum Aggregate Size (mm)

Characteristic 28 day

strength

(N/mm2)

7 day strength

Minimum Cement Content

Workability Slump (mm)

31.5

320 kg/m3

50 – 90

Plain Concrete Class’n	Maximum Aggregate Size (mm)	Characteristic 28 day strength (N/mm2)	Minimum Cement Content
15	31.5		280 kg/m3

B.2.2 Concrete to be Used

B.2.2.1 Unless otherwise stated on the drawings, all concrete shall be Grade 35.

B.2.2.2 Aggregate for water-retaining structures and roads shall have a low drying shrinkage and an absorption as measured according to the relevant standard, generally not greater than 3%.

Note: See paragraph 3.4 for other applicable related documents.

Appendix C FR Requirements

C.1 Reinforcement Quality

C.1.1 Grade of Reinforcement: Unless otherwise required by the drawings, all steel shall be grade Fe E400.

C.1.2 Quality: The contractor shall obtain from the manufacturer or supplier a certificate as evidence of reinforcement quality to the relevant standard.

C.2 Concrete Quality

C.2.1 Grade of Concrete

C.2.1.1 Unless otherwise required by the drawings, reinforced concrete shall be a standard concrete (BCN) mix of strength grade B25 (28 day cylinder strength of 25 N/mm2).

C.2.1.2 Cement shall be CPJ 45 or CPA 55.

C.2.1.3 Maximum aggregate size shall be 20 mm.

C.2.1.4 Minimum cement content shall be 275 kg/m2.

C2.1.5 Ready mixed concrete shall be to XP P18-305.

Note: See paragraphs 3.2 and 3.3 for other applicable related documents.

PURPOSE

SCOPE

RELATED DOCUMENTS

3.1 British Standards Institute (BSI)

3.2 Centre Scientifique et Technique du Batiment (CSTB)

3.3 L’Association Francaise de Normalisation (AFNOR)

3.4 Nederlands Normalisatie-Instituut (NNI)

CONCRETE MATERIALS

4.1 Cement

4.2 Aggregate

4.3 Water

4.4 Additives and Admixtures

4.5 Air Entrainment

Concrete Quality

5.1 Production, Batching, and Mixing

5.2 Sampling and Testing

5.2.3 Sampling

5.2.4 Tests for the Assessment of Strength

5.2.5 Tests for Determination of the Temperature of Fresh Concrete

5.3 Compliance

5.5 Records

5.6 Action to be Taken in Event of Noncompliance

Reinforcement

6.3 Fixing

Formwork

Tolerance

Transporting and Placing

Compaction

Curing and Protection After Placing

11.1 Curing

11.3 Removal of Forms

Finishes

12.1 General

12.2 Finishes from Formwork or Moulds

12.3 Finishes to Horizontal Surfaces

12.4 Special Finishes

Joints and Bonding of Concrete

Concreting in Cold Climate and Cold Weather

Concreting in Hot Climate and Hot Weather

Placing Concrete under Water

Testing for Watertightness of Concrete for Water-Retaining Structures

18.3 Performance

B.2.2 Concrete to be Used

C.1 Reinforcement Quality

C.2 Concrete Quality

C.2.1 Grade of Concrete

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