Maximizing SCM Content of Blended Cements

Today, Portland cement substitutes known as supplementary cementitious materials or SCMs are used to improve the performance while reducing the environmental footprint of concrete. There are several factors that impact the amount of SCMs that can be added to concrete while maintaining its basic integrity. This paper describes a newly developed framework for optimizing the substitution of cement with SCMs in concrete. This framework has been developed based on recent testing results and clearly indicates that paying close attention to cement and SCM particle size distributions (PSDs) and the corresponding packing density of the combined ingredients will allow for an optimization of the cement and SCMs in concrete. This framework has been developed on the basis of several independent laboratory studies and can be adapted as a basis for evaluating and optimizing any combination of cement and SCMs. The means to produce cement/SCM blends with the optimized PSDs with existing equipment configurations are also explored.