SECTION 06400 - REINFORCING STEEL

y spaced so that no reinforcement steel shall be laid upon or come in contact with the ground. When the weather is dry and the time for storage before installation is limited, housing may be omitted, but if rainy or exceptionally humid weather occurs or is anticipated, bars shall be stored under cover.
Steel Quality and Supply 
Representative samples of all reinforcement steel that the Contractor proposes to use in the Works must be submitted, before work is commenced, to the Engineer for his written approval, together with manufacturer’s certificates stating clearly for each sample the place of manufacture, expected date and size of deliveries to the Site, and all relevant details of composition, manufacture, strengths and other qualities of the steel.
In the event a reinforcement steel sample under test fails to meet the specification requirements at any time, or the Engineer considers that samples which were presented to him for test were not truly representative, or if it becomes apparent that reinforcement steel which has not been approved has been used on the Works, the Engineer may instruct the Contractor to break out and remove completely all such sections of the work already constructed using such suspect reinforcement steel.
All testing of reinforcement steel bars shall meet the requirements and specification limits of the ASTM/AASHTO designation for the particular size, grade and any additional requirements. 
bar lists and bending diagrams
The Contractor shall provide detailed bar lists and bending diagrams to the Engineer for review and approval. Fabrication of material shall not begin until such lists have been approved. The approval of bar lists and bending diagrams shall in no way relieve the Contractor of responsibility for the correctness of such lists and diagrams. Any expense incident to the revision of material furnished in accordance with such lists and diagrams to make it comply with the design drawings shall be borne by the Contractor.
Fabrication
Bending
Bar reinforcement shall be cut and bent to the shapes shown on the plans. Fabrication tolerances shall be in accordance with ACI 315. All bars shall be bent cold, unless otherwise permitted. Bars partially embedded in concrete shall not be field bent except as shown on the plans or specifically permitted.
Hooks and Bend Dimensions
The dimensions of hooks and the diameters of bends measured on the inside of the bar shall be as shown on the plans. When the dimensions of hooks or the diameter of bends are not shown, they shall be in accordance with Division I, Article 8.23 or ACI 318, “Building Code Requirements for Reinforced Concrete”.
Bending and Anchorage 
Each reinforcement steel bar shall be cut and bent to the dimensions specified on the Drawings. For some structures the number and length of bars may need measuring on site to be in accord with the dimensions of the structure.
For bending of reinforcement steel bars, the recommendations of the manufacturer shall be adhered to in each case. All bars shall be bent cold. All reinforcement steel requiring bending shall be bent in accordance with American Concrete Institute procedures unless otherwise detailed. Bars partially embedded in concrete shall not be bent except as indicated on the Drawings or otherwise permitted. Qualified men shall be employed for cutting and bending, and proper appliances shall be provided for such work.
Fixing of Reinforcement Steel 
The reinforcement steel shall be assembled to the shapes and dimensions as indicated on the Drawings. The rods shall be of the cross-sectional areas indicated and shall be fixed rigidly and accurately in the forms in the positions indicated on the Drawings. The rods shall be firmly bound together at intersections of rods to ensure that the reinforcement steel framework as a whole shall retain its shape, and the framework shall be so temporarily supported as to retain its correct position in the forms during the process of depositing and consolidating the concrete. The end of all tying wires shall be turned into the main body of the concrete and not allowed to project towards the surface. Spacing blocks shall be of precast concrete of strength at least equal to that of concrete being placed. They shall be as small as practicable and shall be securely fixed in position by means of wires cast into them. They shall be soaked with water immediately prior to concreting.
No temporary metal supports to the reinforcement steel will be allowed by the Engineer to be incorporated in the finished concrete, and metal clips or supports shall not be placed in contact with forms for exposed surfaces.
At the time of concreting, all reinforcement steel shall have been thoroughly cleaned and freed from all loose rust, scale, mud, oil or any other coatings that might destroy or reduce the bond and it shall also have been cleaned of all set or partially set concrete which may have been deposited thereon during the placing of a previous lift of concrete.
The placing of all reinforcement steel bars will be checked by the Engineer and in no case is concrete to be placed around any reinforcement steel that has not been approved by the Engineer. The insertion of bars into or the removal of bars from concrete already placed will not be permitted by the Engineer. Reinforcement steel temporarily left projecting from the concrete at the joints shall not be bent without the prior approval of the Engineer.
Dowels shall project a minimum of 40 bar diameters unless otherwise indicated on the Drawings. Metal supports which extend to the surface shall not be used. Placing bars on layers of fresh concrete as the work progresses and adjusting bars during the placing of concrete will not be permitted by the Engineer.
Main reinforcement steel carrying determinate stresses shall be spliced only where indicated on the Drawings or on approved shop drawings.
The minimum spacing centre to centre of parallel bars shall be 2.5 times the diameter of the bar, but in no case shall the clear distance between the bars be less than 1.5 times the maximum size of the coarse aggregate.
Bundle reinforcement steel bars shall be tied together at not more than 1.80 M centres.
All reinforcement steel shall have a clear coverage as indicated on the Drawings or specified herein.
The cover to reinforcement steel, general limits on bar sizes and spacing of bars shall be as indicated on the Drawings.
Splicing of Bars
General
All reinforcement shall be furnished in full lengths indicated on the drawings unless otherwise approved by the Engineer. Except for splices shown on the plans and splices for 16mm or smaller bars, splicing of bars will not be permitted without written approval. Splices shall be staggered as far as possible.
Lapped Splices
Lapped splices shall be of the lengths shown on the plans. If not shown on the plans, the length of lapped splices shall be no less than 40 bar diameters.
In lapped splices, the bars shall be placed and wired in such a manner as to maintain the minimum distance to the surface of the concrete shown on the plans.
Welded Splices
Welded splices shall be used only if detailed on the plans or if the Engineer in writing makes an authorization. Welding shall conform to the Structural Welding Code. Reinforcing Steel, AWS D1.4 of the American Welding Society and applicable special provisions.
Mechanical Coupler Splices
Splices made with mechanical couplers shall be used only if preapproved or detailed on the plans or authorized in writing by the Engineer. Such couplers shall develop in tension or compression, as required at least 125 percent of the specific yield strength of the bar.
When requested by the Engineer, up to two field splices out of each 100, or portion thereof, placed in the work and chosen at random by the Engineer, shall be removed by the Contractor and tested to 125 percent of the specified yield strength by the Engineer.
Splicing of mesh or mats
Sheets of mesh or bar mat reinforcement shall be spliced by overlapping each other sufficiently to maintain a uniform strength and shall be securely fastened at the ends and edges. The edge lap shall not be less than one mesh in width plus 50 mm.
Measurement and Payment
Measurement
The measurement of reinforcing steel bars will be by kilogram, based upon the total computed weight for the sizes and lengths of bars as indicated in the reinforcing schedules and as approved by the Engineer.
Payment 
Reinforcing Steel Bars shall be paid for in accordance with applicable Unit Prices as indicated on the Bid Price Schedule. Payment shall be considered as full compensation for all labor, materials, tools, equipment and appurtenances for the complete furnishing and installing of all reinforcement steel bars.
No separate payment will be applicable for clips, wire, separators, wire chairs, and other material used in fastening the reinforcement in place. In the event that bars are substituted upon the Contractor’s request and as a result more steel is used than specified, only the amount specified shall be included in the quantity for payment.
When laps are made for splices, other than those indicated on the Drawings or approved shop drawings for the convenience of the Contractor, the extra steel will not be included for payment.
For computing weight of reinforcement steel bars for payment, the following weights shall be used:
Bar Diameter (mm)
Kg/Meter
Area (cm2)
6
0.22
0.283
9
0.50
0.636
10
0.617
0.79
12
0.888
1.13
13
1.034
1.33
14
1.210
1.54
16
1.580
2.01
18
2.000
2.54
19
2.240
2.84
20
2.470
3.14
22
2.980
3.80
24
3.550
4.52
25
3.850
4.91
26
4.170
5.31
28
4.830
6.16
29
5.03
6.41
30
5.550
7.07
32
6.310
8.04
36
7.990
10.18
38
8.900
11.34
40
9.870
12.56
43
11.38
14.52
57
20.24
25.81
Pay Item
Description
Unit
06400-1
Reinforcing Steel – Deformed Bars
kg
06400-2
Reinforcing Steel – Plain Bars
kg