Simple methods to estimate the influence of limestone fillers on reaction and property evolution in cementitious materials

A commercial interest in sustainable cementing materials is driving efforts to reduce the use of cement in concrete. Limestone fillers are a promising direction towards achieving such cement use reductions. In spite of increasing filler use, little information is available to rapidly estimate the influences of limestone fillers, and more importantly filler fineness on reaction and property development. This work develops simple models to predict the effect of particle size classified limestone on hydration reactions and compressive strength development. The method builds on a relativistic basis, such that enhancements and alterations in reactions and properties are described in relation to a given control (pure cement) mixture. The prediction method considers aspects such as: (1) accelerations in reactions, (2) changes in inter-particle spacing as linked to the limestone filler’s fineness and (3) a porosity increase with increasing cement replacement. The predictive power of the approach is demonstrated for a variety of mixtures composed using three ASTM C150 compliant cements and forwards a basis for developing mixture proportioning strategies, such that apriori estimations of the mixture response (reaction rate and mechanical properties) can be used to optimize binder proportioning and thus strategize new methods to limit cement use in concrete construction applications.