Astm, Aashto Inch Toward Harmonizing C 150, M 85

In a move Portland Cement Association notes will likely simplify concrete quality control for agency work, the American Association of State Highway and

In a move Portland Cement Association notes will likely simplify concrete quality control for agency work, the American Association of State Highway and Transportation Officials’ Subcommittee on Materials and ASTM International’s Committee C01 on Cement recently passed ballot proposals to harmonize three of five key provisions between AASHTO M 85 and ASTM C 150 portland cement standards. The standards’ 2007 editions will have consistent provisions for fineness, Type II calcium silicate content, heat of hydration-related criteria, and use of up to 5 percent ground limestone. These changes stem from a harmonization effort initiated in the summer of 2003. AASHTO M 85 and ASTM C 150 have existed as parallel standards for portland cement since the 1940s. State departments of transportation reference one (or sometimes both) of these standards when specifying portland cement for concrete.