Exploring the applicability of thermodynamic modeling to predict the degree of reaction of supplementary cementitious materials in Portland cements

A reaction degree of supplementary cementitious materials (SCMs) in hydrated Portland cement is an important factor that enables prediction of the performance of concrete, while conventional methods for estimating the degree of reaction of SCMs are generally time-consuming and complicated. This study investigated the applicability of thermodynamic modeling as an alternative and potentially less complicated means of predicting reaction degrees of SCMs. The reaction degrees and bound water contents of slag- and fly ash-blended Portland cement were experimentally measured at various sample ages by selective dissolution and thermogravimetric analysis, respectively, and compared with thermodynamic calculations. The results suggest that reasonably accurate and comparable predictions of bound water and degrees of reaction of SCMs can be made, which is promising and shows the potential of this approach to be used as an alternative and simple approach to predict the degrees of reaction of SCMs in hydrated Portland cement.