AASHTO M 31M/M 31-19 PDF Download

The AASHTO M 31M/M 31-19 standard specifies the requirements for deformed and plain carbon and low-alloy steel bars used for concrete reinforcement. These bars can be provided in cut lengths or coils. The standard allows for the use of steel bars with alloy additions, as long as they meet all other requirements of the specification.

The standard provides a table that lists the standard sizes and dimensions of deformed bars, along with their number designations. The bars are categorized into four minimum yield strength levels: Grade 280 [40], Grade 420 [60], Grade 520 [75], and Grade 550 [80], which correspond to yield strengths of 280 MPa, 420 MPa, 520 MPa, and 550 MPa, respectively.

Additionally, the standard distinguishes between two types of bars based on their carbon content. Bars with carbon contents of 0.30 percent or less and meeting the specified carbon requirements are designated as Type W. Bars with carbon contents greater than 0.30 percent are designated as Type S. This classification helps to ensure that the bars meet the specific requirements for their intended use in concrete reinforcement.