Rheology and early age properties of cement systems

Abstract

This study investigates the effect of fine aggregate (FA) gradation on the rheology of mortar. For the convenience of analysis, spherical glass beads with a specific gravity of 2.50 were employed as FA. The mortar mixtures were proportioned with water-to-cement ratio of 0.3 and volumetric content of FA of 0.1–0.5. The results indicated that the FA gradation had an influence on the rheology of mortar, and the influence increased with the increase in volume fraction of FA. According to hydrodynamics, the effect of FA gradation can be attributed to the coupled effect of packing fraction, specific surface area, and equivalent diameter of FA. This coupled effect can be evaluated by the parameter D/PFT. In addition, the rheological parameters of mortar (relative yield stress and relative plastic viscosity) increased monotonically with the increase in D/PFT, and exponential functions can well express their relationships.