Study of Swelling and Shrinkage Characteristics of Expansive Soil Using Silica Gel as an Admixture

Expansive soils are characterized as soil which undergo large volume changes on availability of moisture. The continuous cyclic wetting and drying process cause vertical and horizontal movement in expansive soil which leads to failure of engineering structure erected on such soils (Masoumeh and Masoud in Electronic Journal of Geotechnical Engineering 17:2673–2682, [1]). The expansive soil has very low bearing capacity, high plasticity, high compressibility, low permeability, high swelling and shrinkage properties, due to the presence of montmorillonite mineral. The expansive soil contains the clay particle of medium to high compressibility and covers nearly 20% of geographical area in India which is the concern of study (Zhang and Cao in Journal of Wuhan University of Technology 17:73–77, [2]). In this research, silica gel as admixture is used to aid the properties of parent material. This study aims to conduct soil stabilization of black cotton soil of North Gujarat region by using silica gel in different proportion. In this research paper, silica gel is added 2, 4, 6, 8 and 10% by weight to give comparison between the soil properties of untreated soil and treated soil. Due to the addition of 10% of silica gel by mass in virgin soil, l plastic limit increased by 16.72% and liquid limit decreased by 19.23% which ultimately decreases plasticity index by 57.5. Also it was found that MDD is decreased by 4.3%, and free swell index decreased by 41.56% on addition of 10% silica gel by mass.