Stabilizing Expansive Soil with Industrial Waste of Coir and Terrasil

Abstract

Black cotton soils either swell or shrink on seasonal variation of water content. Soil swells if it absorbs water and shrinks once the water evaporates. Constructions on expansive soil pose several difficulties such as settlements, cracks in the superstructures, low strength, and high volume change. Different stabilization techniques have been used to alter the properties of soil. Stabilizing black cotton soil with industry waste is an economical way to enhance the soil for construction purposes. This study discusses the use of coir and terrasil chemical to improve the subgrade properties of expansive soil. Experiments are conducted on black cotton soil with and without admixtures. Various combinations of coir (0.25%, 0. 5% and 0.75%) and terrasil (0.04%, 0.06% and 0.08%) have been mixed with the soil, and the optimum proportion have arrived. The addition of soil blended with optimum percentages of coir (0.75%) and terrasil (0.06%) gave better strength characteristics to the subgrade. This combination reduces the construction cost and enhances durability. IS code methods are used, to obtained Optimum Moisture Content (OMC) 28%, Maximum Dry Density (MDD) 18.25kN/m2, and Unconfined Compressive Strength (UCS) 197.36 kPa. Adding these admixtures reduces the plasticity property of the original soil and finally, it modifies as less plastic material and offers more strength.