Q: What is a binary concrete mixture?

A: When a concrete mixture design includes portland cement and a single supplementary cementitious material (SCM), it is referred to as a binary mixture. Similarly, if two SCMs are used with portland cement to make concrete, that is referred to as a ternary mixture. Using three different SCMs with portland cement results in a quaternary mixture. These mixtures can be arrived at either through the use of blended cements—which are discussed in ACI 225R-99,"Guide to the Selection and Use of Hydraulic Cements"—or by combining the individual ingredients as the concrete is mixed.

A good overview of SCMs is available on the Portland Cement Association Web site, www.cement.org, in the Concrete Technology FAQs.