Performance Assessment of Copper Slag and Sawdust Ash in Stabilization of Black Cotton Soil

Abstract

Stabilization of black cotton soil becomes mandatory to reduce the degree of swelling and shrinkage and makes the soil productive for the construction of structures and pavement subgrades. To make use of the surplus solid waste materials and to mitigate its harmful environmental effects, the solid waste acts as a better alternative for stabilizing agents. The present research focuses on the incorporation of solid waste material such as copper slag (CS) and sawdust ash (SA) for the stabilization of black cotton soil. The experimental investigations are carried out with a partial replacement of copper slag (CS) at 10%, 20%, 30%, 40%, and sawdust ash (SA) at 2%, 4% and 6%, respectively. The properties such as specific gravity, wet sieve analysis, liquid limit, plastic limit, moisture content and free swell index are determined. Unconfined compression (UCC) and California bearing ratio (CBR) tests are performed to determine soil strength with different percentages of copper slag and sawdust ash, and the results are compared to unexplored soil. From the observations, replacement of 30% copper slag and 4% sawdust ash is exposed as an optimum percentage of replacement. The unconfined compressive strength is found to be 92 kN/m2, and CBR values are 4.71 and 4.581 at 2.5 mm and 5 mm penetration, respectively. From the experimental investigation, it is apparent that the optimum replacement of solid waste materials like copper slag and sawdust ash in the black cotton soil productively enhances the soil stabilization and upgrades its application in structure and pavement constructions.