ITEM 710 – REINFORCING STEEL AND WIRE ROPE

710.1 Reinforcing Steel

Reinforcing steel shall conform to the requirements of the following Specifications:

Deformed Billet-Steel Bars                         AASHTO M 31

for Concrete Reinforcement          (ASTM A615/PNS 49)

Deformed Steel Wire                                   AASHTO M 225 (ASTM A496)

for Concrete Reinforcement

Welded Steel Wire Fabric

for Concrete Reinforcement          AASHTO M 55 (ASTM A185)

Cold-Drawn Steel Wire                               AASHTO M 32 (ASTM A82)

            for Concrete Reinforcement

Fabricated Steel Bar or Rod Mats             AASHTO M 54 (ASTM A184)

for Concrete Reinforcement

Welded Deformed Steel Wire Fabric        AASHTO M 221 (ASTM A497)

            of Concrete Reinforcement

Plastic Coated Dowel Bars                        AASHTO M 254 Type A

Low Alloy Steel Deformed Bars                ASTM A 206

for Concrete Reinforcement

Bar reinforcement for concrete structures, except No. 2 bars shall be deformed in accordance with AASHTO M 42, M 31 and M 53 for Nos. 3 through 11.

Dowel and tie bars shall conform to the requirements of AASHTO M 31 or AASHTOM 42 except that rail steel shall not be used for tie bars that are to be bent and restraightened during construction. Tie bars shall be deformed bars. Dowel bars shall be plain round bars. They shall be free from burring or other deformation restricting slippage in the concrete. Before delivery to the site of the work, a minimum of one half (1/2) the length of each dowel bar shall be painted with one coat of approved lead or tar paint.

The sleeves for dowel bars shall be metal of an approved design to cover 50 mm (2inches), plus or minus 6.3 mm of the dowel, with a closed end, and with a suitable stop to hold the end of the sleeve at least 25 mm (1 inch) from the end of the dowel bar. Sleeves shall be of such design that they do not collapse during construction.

Plastic coated dowel bar conforming to AASHTO M 254 may be used.

710.2 Wire Rope or Wire Cable

The wire rope or wire cable shall conform to the requirements of AASHTO M 30 for the specified diameter and strength class.

710.3 Prestressing Reinforcing Steel

Prestressing reinforcing steel shall conform to the requirements of the following Specifications:

High-tensile wire                              AASHTO M 204 (ASTM A421)

High-tensile wire strand or rope    AASHTO M 203 (ASTM A416)

High-tensile alloy bars as follows:

High-tensile-strength alloy bars shall be cold stretched to a minimum of 895.7 MPa. The resultant physical properties shall be as follows:

Minimum ultimate tensile strength           1000 MPa followed by stress relieving

Minimum yield strength, measured by     895.7 MPa

the 0.7 percent extension under load

method shall not be less than

Minimum modulus of elasticity                  25,000,000

Minimum elongation in 20 bar                  4 percent

diameters after rupture

Diameters tolerance                                    +0.762 mm – 0.254 mm

If shown on the Plans, type 270 k strand shall be used, conforming to AASHTO M203.