Effect of fly ash on the index properties of black cotton soil

Abstract

This paper presents the effect of abundantly available fly ash, on the index properties namely liquid and plastic limits, and free swell of natural deposits of Indian black cotton soil. The effects of lime when added have also been studied. Considerable changes in these properties were observed which are explained based on grain size distribution, free lime content and pozzolanic reactivity of fly ash. Addition of fly ash improved the workability of the soil considerably. The increase in free swell in the presence of fly ash is not due to increase in the swelling potential of the soil. Over all, the effect of the addition of fly ash is to significantly improve the physical properties of the black cotton soil.