Stabilization of expansive soil with terrasil and coir fiber as a subgrade for pavement

Abstract

This research is intended to enhance the strength and permeability properties of black cotton soil or expansive soil of high plastic clay (CH) by combining soil with coir fibre and Terrasil additives. The distributions of the additive’s coir fibre and Terrasil used in the analysis are expressed as a percentage of the soil’s dry weight. The Terrasil and coir fibre proportions used in this study are 0.5% Terrasil and 0.5%,1.0%,1.5%, and 2.0% coir fibre, respectively. According to the analysis or test results, clay subgrade soil stabilized with 0.5% Terrasil and 1.5% coir fibre exhibits specific values for strength and CBR value improvement. The UCS confidence interval for the combined application of soil+0.5%Terrasil+1.5%coir fibre increases from 26.566 kpa to 27.209 kpa in the untreated soil. The CBR computed value for the treated soil is 90% usually higher than the untreated soil, lowering the layers demanded for the subgrade. Permeability values of 1.5% and 2.0% for coir fibre and 0.5% for Terrasil outperformed that of untreated soil. After the additives are incorporated into the soil, the mineralogy of the soil and the Bonding mechanism phenomena are inspected (or) investigated using XRD, SEM, and FTIR.