Engineering behavior of a remolded expansive clay blended with lime, calcium chloride, and rice-husk ash

This paper presents experimental results obtained from tests conducted on remolded expansive soil specimens blended with rice-husk ash (RHA) and stabilized with lime and calcium chloride. The amounts of RHA, lime, and calcium chloride were varied from 0 to 16%, 0 to 5%, and 0 to 2%, respectively, by dry weight of the soil. The effect of additives on unconfined compressive strength (UCS) and California bearing ratio (CBR) is reported. It was found that the stress-strain behavior of expansive clay improved upon the addition of up to 5% lime or up to 1% calcium chloride. A maximum improvement in failure stress of 225 and 328% was observed at 4% lime and 1% calcium chloride, respectively. A RHA content of 12% was found to be the optimum with regard to both UCS and CBR in the presence of either lime or calcium chloride. An optimum content of 4% in the case of lime and 1% in the case of calcium chloride was observed even in clay-RHA mixes.