Evaluating the Strength Characteristics of Lime and Metakaolin Stabilized Expansive Soil

Abstract

Expansive soils, such as black cotton soils, are a worldwide problem. Construction on this soil has been drawing the attention of practicing engineers and researchers for many years. With changes in moisture regime, expansive soils are subjected to erratic changes in volume. In monsoon, predominantly they take up water and swell but in summer, they tend to shrink on evaporation of water, thus posing the problem of alternate cycles of swelling and shrinkage. This behavior of expansive soils is attributed to the presence of mineral-montmorillonite, which has an expanding lattice. Many researches, all over the world, are working to evolve more effective and practical treatment methods, to mitigate the problems posed to the construction of pavements on expansive soil sub grade. Stabilization is one of the effective methods adopted to improve the characteristics of expansive soils. Of late, good stabilizing agents like lime, cement and metakaolin are employed extensively in soil stabilization for building foundations or pavement sub-grades. Keeping in view the research findings outlined above, in the present work, experimentation was carried out to investigate the efficacy of different additives, Viz., Lime, Metakaolin and Lime + Metakaolin combination, in stabilizing the expansive soil sub grade, thereby, improving the strength and reducing swelling potential of stabilized soil.