Impact of filler on hydration kinetics

ABSTRACT Quartz particles have been used to investigate the filler effect of slag in cement paste. The isothermal calorimetry data for quartz-cement paste when quartz has a similar specific surface area to slag particles were identical up to 24 hours. Over this period slag does not react chemically, however it enhances the acceleration period compare to plain cement. The surface factor seems involved in the controlling mechanism as quartz and slag with same particle size showed similar acceleration rate. After 1 day the slag reaction is dominant. The quartz-cement systems which simulate the filler contribution of slag, revealed that at long term the kinetics are mainly affected by the space available. Cement and blended systems with the same w/c ratio have a similar cumulative heat release at 28 days