AASHTO MP 18M/MP 18-09 (2010)

This specification covers uncoated, corrosion-resistant, deformed and plain alloy, billet-steel concrete reinforcement and dowel bars in cut lengths or coils, where corrosion-resistant performance may be essential. The standard sizes and dimensions of deformed bars and their number designations shall be those listed.

Bars are of three minimum yield levels: 420 MPa [60000 psi], 520 MPa [75000 psi], and 690 MPa [100000 psi], designated as Grade 420 [60], Grade 520 [75], and Grade 690 [100], respectively.

Hot-rolled plain rounds, in sizes up to and including 50.8 mm [2 in.] in diameter in coils or cut lengths, when specified for dowels, spirals, and structural ties or supports shall be furnished under this specification in Grade 420 [60], Grade 520 [75], and Grade 690 [100]. For ductility properties, test provisions of the nearest nominal diameter deformed bar size shall apply. Those requirements providing for deformations and marking shall not be applicable.

Note - The weight for plain rounds smaller than 9.5 mm [3/8 in.] in diameter shall be computed on the basis of the size in ASTM A 510.

Note - Welding of the material in this specification should be approached with caution since no specific provisions have been included to enhance its weldability. When the steel is to be welded, a welding procedure suitable for the chemical composition and intended use or service should be used.