Effect of Sulphate Contamination on Lime-Stabilized Black Cotton Soil

Chemical stabilization using lime is considered as a suitable practice to suppress the swelling and shrinkage behaviour of expansive soils. However, several distress encountered throughout the world in lime-stabilized sulphatic soil is mainly due to the generation of heave which leads to the questioning of the effectiveness of lime stabilization. An attempt has been made in the present study to examine the physical and swell behaviour of lime-stabilized expansive soil under sulphate contamination. Detail experimental investigations have been done on untreated and lime-treated soil contaminating with varying concentrations of sodium sulphate (0–30000 ppm). The results revealed that sulphate contamination influences significantly the swell index of soil. Irrespective of sulphate concentration, the swell index of lime-treated soil is observed to be more than that of the same with untreated soil. The formation of expansive mineral, i.e. ettringite results in swell in lime-treated soil.