Characterization and Effective Utilization of Coal Ash With Geosynthetics in Pavement Subgrade

摘要

Pavements on black cotton soils fail during adverse weather conditions due to swelling and shrinkage characteristics of such soils. Stabilization of black cotton soils, therefore, becomes mandatory. Geosynthetics are soil stabilization materials used to improve soil conditions in various applications. Coal ash is available at low cost and it is utilized for the stabilization of black cotton soils. The present study aims to utilize coal ash, effectively in pavement subgrade. In phase I of the research, index and engineering properties of virgin soil is studied and the soil is classified under CH (clay of high compressibility) category. Coal ash is added to the soil by 10%, 20%, 30%, 40%, 50% replacements to the weight of soil- The shear strength of virgin soil is 90.60 kN/m~2 at an optimum moisture content of 21% and maximum dry density of 1.6807g/cc. The California bearing ratio (CBR) values of the virgin soil under unsoaked and soaked conditions are 5.33% and 2.84%, respectively. This study shows that the shear strength, optimum moisture content, maximum dry density is maximum at an optimum of 10% addition of coal ash to the soil. Atterbergs limits and plasticity index decreases with the addition of coal ash.