Study of Swelling Potential of Copper Slag Cushion Laid Over Expansive Soil Bed

Abstract

Expansive soils are subjected to changes in volume with seasonal water content variations. Techniques like sand cushion and cohesive non-swelling cushion have been tried to minimize the heave of expansive soils. But, they have inherent limitations. Utilization of waste materials in civil engineering has been in vogue all over the world in recent times and is primarily needed because of the problems associated with their disposal. Copper slag is one such waste material. Research carried out by the authors using lime-stabilized and cement-stabilized copper slag as cushioning material over expansive soil beds was found effective in minimizing heave of expansive clay beds. Heave studies were conducted using the stabilized cushions over expansive clay beds with thickness ratios of the cushion to the soil bed varying as 0.25, 0.50, 0.75 and 1.00. Percentage of lime and cement was also varied from 2 to 10%. The present paper discusses the experimental results of the swelling studies conducted on the cushion-soil system. It was noticed that, with an increase in the percentage of lime or cement, there is an increased reduction in heave.