Effect of grinding time on the particle size distribution of gasification ash and Portland cement clinker

Abstract

In recent years the cement and concrete industry has reduced its environmental impact by increasing the use of waste materials as both cement extenders and fillers in concrete. Fly ash has been widely used as a cement extender in concrete for many years but the use of ash from other industries has been limited. In this study the use of ground coarse gasification ash as cement extender is investigated. The effect of grinding time on the particle size distribution (PSD) of gasification ash (GA) and Portland cement (PC) clinker was investigated. The PSD was determined for both blended GA and PC clinker that were first ground separately and interground GA and PC clinker. There appeared to be an optimum grinding time for the GA and interground of GA and PC clinker beyond which the fineness did not increase significantly. The particle size range was narrow after two hours' grinding and any increase in grinding time made it wider for GA and the blended cement. The fineness and Blaine specific surface area of GA and PC clinker increased with an increase in grinding time. However, this increase was less significant beyond two hours. The fineness had an effect on the rate of strength development of the blended cement. The compressive strength, particle size and Rosin-Rammler distribution parameters clearly indicated that grinding time should not be shorter than two hours for interblending and intergrinding of GA and PC clinker