ABSTRACT
Laboratory experiments have shown that lime stabilization is effective in controlling the swell potentials of expansive soils on first wetting. Expansive soils however experience repeated wetting and drying in the field due to environmental effects. The swelling behaviour of natural expansive soils on multiple wetting and drying is usually different from that observed on first wetting. The present study hence examines whether lime stabilization reactions are effective in controlling the swelling behaviour of expansive soils after multiple wetting-drying cycles. Expansive soil specimens treated with a range of lime contents were cured/mellowed for a period of 10 days. The cured specimens were subjected to cycles of full wetting and drying in the laboratory in modified oedometer assemblies. Experimental results showed that the swelling tendency of lime-stabilized expansive soils drastically increased after one cycle of wetting and drying. The swell potentials of the lime- stabilized specimens slightly decreased with additional wetting-drying cycles and attained equilibrium after five wetting and drying cycles. The combined effects of breakage of cementation bonds, reduction in void ratio and water content increased the swell potentials of the lime-stabilized specimens after the first wetting-drying cycle.
