The effect of grinding on the physical properties of fly ashes and a Portland cement clinker

The effect of the grinding on the physical properties of three ASTM Class F fly ashes and a Portland cement clinker were investigated. The specific gravity and the fineness of the Ay ashes increased with an increase in the grinding time. However, this increase was less significant beyond 2 h. The morphology of the fly ashes was changed by grinding. Most of the plerospheres and large, irregular-shaped particles were crushed after 2 h of grinding. However, the number of the spherical particles reduced with increased grinding. There appears to be an optimum grinding time of approximately 4 h for the Ay ashes beyond which the water requirement increased and the strength activity indices either decreased or did not increase significantly. (C) 1997 Elsevier Science Ltd.