Subcommittee on Materials

The AASHTO ASR Task Group plans to propose a Standard Recommended Practice for Determining the Reactivity of Concrete Aggregates and Selecting Appropriate Measures for Preventing Deleterious Expansion in New Concree Construction.  Table 6, Minimum Levels of SCM to Provide Various Levels of Prevention in this Standard mentions the Alkali Level of SCM (%Na2Oe) in one column.  The information in this column will require the following changes to M 295, M 302, M 307, and M 321.

 

M 295 - The Table 2 percent Na2O equivalent limits should be changed to "Report value only".  See Table 2 in M 321.

M 302  and M 307- A percent Na2O equivalent table with "Report value only" will be needed.

M 321 - Table 2 should be clarified that this is Na2O "equivalent".