Effect of Fly Ash and Rice Husk Ash on Permanent Deformation Behaviour of Subgrade Soil under Cyclic Triaxial Loading

This work presents the laboratory study conducted on fly ash and rice husk ash as soil stabilizers. Using these stabilizers, the deformation behaviors of subgrade soil-mixtures under repeated triaxial loading was conducted. Resilient strain, permanent strain and resilient modulus were ascertained at different deviator stress level and confining pressures at constant moisture content. Admixing of fly ash and rice husk ash reduces the maximum dry density but increase the water demands. The variations of elastic deformation and resilient modulus were significantly influenced by fly ash and rice husk ash contents. Better performances were observed for admixed soil irrespective of number of load applications. The results obtained from the laboratory confirm the potential use of subgrade soil admixed with fly ash and rice husk ash with respect to the permanent deformation.