Cement with high-volume limestone powder: effect of powder fineness on packing density, strength and hydration behaviour

Abstract

To study effects of limestone powder with different fineness on packing density, strength and hydration behaviors of cement blending high-volume limestone powder, Vicat setting time test, strength test, isothermal calorimetry and scanning electron microscopy were employed. Results showed that cement replacement by limestone powder with smallest median particle size had the largest packing densities in three different fineness of limestone powder replacement. The compressive strength of blended cement mortar increased with the increasing of limestone powder fineness. Furthermore, packing densities of blended cement could be used to infer the evolution of mechanical strength of the blended cement mortar. The addition of limestone powder with smaller median particle size than that of cement accelerated the hydration of cement in acceleration period. Compared to limestone powder with smaller median particle size than that of cement, the producing rate of nuclei of cement blending limestone powder with larger median particle size than that of cement decreased with increasing amount of limestone powder replacement, while growth rate of nuclei increased with increasing amount of limestone powder replacement.