Characterization of Ground Granulated Blast-Furnace Slags and Fly Ashes and Their Hydration in Portland Cement Blends

Abstract

Abstract Chemical analysis, glass content, particle size distribution, heat evolution rate and total heat evolved, scanning electron micrographs and strength development have been studied for three granulated blast furnace slags of different origin and two fly ashes of low and high CaO content. At all ages heat evolution rates and total heat evolved by the fly ashes are lower than the corresponding values for the granulated blast furnace slags, regardless of their origin. In the blends studied, high-lime-content fly ash develops higher compressive strengths than low-lime fly ash above the 25% portland cement replacement level. The results of the study indicate that 50% portland cement replacement by the high-lime-content fly ash used may provide an acceptable compromise to obtain concrete with high compressive strength and low heat of hydration.