Physical and Geotechnical Perspectives of Gypsum on Lime Stabilized Expansive Soil: A Critical Appraisal

Abstract The gypsum is the source of sulphate commonly found in the soils throughout the world. The expansive soils are considered as problematic soils as they exhibit uncertain swelling and shrinkage in presence of moisture. The expansive soils are treated with different stabilizers to suppress the swelling behaviour. Lime is most effective stabilizer used to stabilize the expansive soil. Researchers reported that expansive soil when treated with lime encounters the gypsum it regenerates the swelling. This regenerated expansion of lime treated soil in presence of sulphate may have alarming signs for sulphate bearing soils. The presence of sulphate alters the mineralogical behaviour of expansive clay. The stabilization additive used f or such soils needs more attention. A comprehensive approach towards proper understanding of the effects of gypsum on lime stabilized soil is required in order to understand the future threats of expansive soils. In this paper, an attempt has been made to present a comprehensive review on the effects of (Gypsum) calcium sulphate dihydrate on the physical properties of untreated and lime treated expansive soil have.