ASTM International's proposed Specification for Blended Supplementary Cementitious Materials standard will enable more concrete producers to blend slag, natural pozzolans, fly ash and silica fume with conventional portland cement — an option that has typically been limited to larger operators with multiple powder silos. “Blending to optimize performance will ultimately encourage the use of supplementary cementitious materials in concrete and support sustainable building practices,” says Lafarge North America Blended Cement Product Manager Gregory Daderko, chair of the task group working on the WK12964 standard.

The group is revising a draft of the standard to continue balloting through the Subcommittee C09.24 on Supplementary Cementitious Materials in advance of proposing it to the main ASTM Committee C09 on Concrete and Concrete Aggregates, whose next meeting is June 24-27 in Norfolk, Va. The most likely WK12964 users, Daderko adds, will be silo-constrained concrete producers and supplementary cementitious material suppliers that have access to multiple products and the desire to produce a blended product to meet specific customer needs. Requests for additional information on the standard and inquiries on contributing to the task group work can be directed to Daderko, greg.daderko@lafarge-na.com, or ASTM Manager of Technical Committee Operations, James Olshefsky, jolshefs@astm.org.