ENHANCEMENT IN IMPROVEMENT OF CLAYEY SOIL WITH ADDITION OF CALCIUM CHLORIDE, RICE HUSK ASH AND POLYPROPYLENE FIBRE

In India, a major portion of total land area is covered by clayey soil. Of this, a large portion is expansive soil. Structures constructed over this expansive soil may be severely damaged due to its high swell shrinkage behavior. So such soil needs to be stabilized to increase its strength, durability and to prevent erosion. As Soil stabilization is the technique used to improve the geotechnical properties of soil and has become the major practice in construction engineering Expansive soils are not stable during all moisture conditions due to swelling and shrinkage properties. Hence they are stabilized properly to reduce extensive damage to the structures. Utilization of industrial waste materials in improving the soil properties is cost effective and environmental friendly method. The present study is carried out to establish the viability of using the combination of rice husk ask and calcium chloride and polypropylene fiber in stabilizing expansive soils. In experimental evaluation, the observations are made for different mixes like soil-rice husk ash, soil-rice husk ash- calcium chloride and polypropylene fiber at different proportions. Rice husk ash was as constant for all mixes to obtain the base line values and calcium chloride at 1%, 2%, 3% was added to untreated soil and polypropylene fiber at 0%, 0.5%, 1%, !.5%. Test specimens were subjected to unconfined compressive tests at 1, 3, 7, 14 and 28 curing days. Free swell index test and Atterberg limit test were conducted at 28 days curing. It was observed that mixes with calcium chloride exhibited high strength, low plasticity index and low free swell index at 28 day curing.