Stabilization of Pavement Sub Grade with Stone Dust, Fly Ash and Tire Rubber to Withstand the Fatigue and Rutting

Abstract

The existing practice of subgrade has been modified with the unique type of subgrade that can withstand running traffic >20msa with 90% reliability. This can be achieved by adding fly ash, stone dust and tire rubber to pavement subgrade. This modified subgrade Mix was prepared to improve the strength of subgrade. Conventional and modified subgrade pavement mixes were tested with CBR values and the resilient modulus of conventional and modified subgrade has been found as per IRC 37-2008. Plate load test has been carried out in the laboratory with the continuous loads on the subgrade and the moduli of subgrade reaction obtained finally were compared analytically using IIT Pave software. The optimal mix proportion of Modified subgrade denotes (subgrade soil with 22% Stone Dust, 4% Fly Ash and 2% Tire Rubber). The modified subgrade in flexible pavement showed an increase in bearing capacity, resilient modulus (Mr) and modulus of subgrade reaction (k) which gave fruitful results with the optimum mix proportion with stone dust, fly ash and tire rubber. The usage of these materials in the construction of pavements decreases the industrial waste, minimizes the environmental pollution, decreases the pavement thickness as well as increases the pavement life.