Study on Influence of Coir and Chemicals in Properties of Expansive soils

Expansive soils exhibit low shear strength, consolidation settlement, swelling and shrinkage, etc., when in contact with water. In order to improve the engineering properties, the common method used is stabilization. In this project, experimentation is carried out to investigate the influence of additives, such as flyash, potassium chloride and coir on compressive strength, California bearing ratio and shear strength of the clay soil. The three additives are added and the tests are carried out by keeping flyash and potassium chloride proportions as constant (30% and 1%) and varying the proportion of coir (0.1%, 0.2%, 0.3% and 0.4%). Control sample with separate addition of flyash (30%), potassium chloride (1%) and a combination of potassium chloride and flyash (30% and 1%) are analyzed for index properties. In addition, coir is added and the engineering properties are also analyzed. The maximum dry density of flyash and potassium chloride added soil goes on increasing with addition of coir upto 0.3% by weight and then it gets decreased. But the optimum moisture content goes on decreasing by increasing the percentage of coir. The results shows improvement in california bearing ratio (CBR) value, compressive strength and shear strength of composite containing flyash, potassium chloride and coir (30% : 1% : 0.3%). Hence the addition of flyash, potassium chloride and coir can be effectively used for soil stabilization.