Effect of Nano-Silica on Performance of Black Cotton Soil

Abstract

Black cotton soil exhibit high swelling and shrinking when exposed to changes in moisture content and hence have been found to be most troublesome from engineering considerations. Black cotton soil is one of the major soil deposits of India, so there is a need of enhancing its geotechnical properties and make it suitable for the construction purpose. There have been many methods available to controlling the expansive nature of the soils. The stabilization of soil by adding different binding materials such as enzymes, biopolymers, emulsions, cement, lime, bitumen, etc. is the conventional and effective method for improving the geotechnical properties of soil. Treating the black cotton soil with nano-silica powder is one of the techniques to improve the behaviour of black cotton soil. Hence, in the present work, the experimentation is carried out to study the effect of adding nano-silica on geotechnical properties of black cotton soil especially Atterberg limits, compaction characteristics, unconfined compressive strength, CBR value and swelling pressure. Nano-silica was mixed with soil in three different percentages (i.e. 0.3, 0.6 and 0.9 % by weight of soil). Based on obtained results, in order to reach the maximum increase in strength parameters, the optimum nano-silica content occurs at 0.6 %.