Effect of Industrial and Agricultural Wastes in the Stabilization of Expansive Soil for the Pavement Subgrades

摘要

The need to bring down the cost of waste disposal and the increasing cost of soil stabilizers has led to intense global research towards economic utilization of wastes for engineering purposes. The safe disposal of industrial and agricultural waste products demands urgent and cost effective solutions because of the debilitating effect of these materials on the environment and to the health hazards that these wastes constitute. Infrastructure projects, such as highways, railways, water reservoirs, reclamation, etc., require earthmaterial in very large quantity. In urban areas, borrow earth is not easily available which has to be hauled from a long distance. Quite often large areas are covered with highly plastic and expansive soil, which is not suitable for such purpose. Extensive laboratory and field trials have been carried out by various researchers and have shown promising results for application of such expansive soil after stabilization with traditional stabilizing agents, such as cement,lime, bitumen, etc.The growing cost of traditional stabilizing agents and the need for the economical utilization of industrial and agricultural wastes has prompted an investigation into the stabilizing potential of coal ash, groundnut shell ash and bagasse ash in highly expansive soil. In this study an attempt has been made to utilize the industrial and agricultural wastes, such as coal ash, groundnut shell ash and bagasse ash as stabilizing agent. The effect of industrial and agricultural wastes on certain properties of soil, such as optimum moisture content, maximum dry density, unconfined compressive strength and California bearing ratio (CBR) has been studied. It has been observed that 45% of coal ash and 8% of groundnut shell ash and bagasse ash are the optimum percentage, which gives the maximum CBR value.