Strength and mechanical behavior of soil–cement–lime–rice husk ash (soil–CLR) mixture

This study presents results of geotechnical investigations on treated silty sand soil with cement, lime and rice husk ash (CLR) and cement-lime (CL) admixture. Consolidated undrained triaxial test and unconfined compressive test were performed to estimate the potential of CLR and CL. The study investigates the influence of the amount of CLR%, main effective stress and curing days on soil strength, deformation, post peak behavior and brittleness. The percentages of the additives of CLR and CL varied from 2.5 to 12.5 % by dry weight of the soil with dry densities of 14.5 kN/m3 and the curing times of 3, 7, 28 and 60 days were examined. From the results, the stress–strain response is strongly influenced by the CLR contents and effective confining pressure. Strength and post peak strength of the CLR–soil are greatly improved by an increase in binder content. An increase of the effective cohesion c′ (kPa) and effective friction Φ′ (degree) is observed with increasing the CLR content, consistently. Brittle behavior observed at lower confining pressures and high CLR content. For both CLR and CL additives, linear trend was observed for variation of the qu (kPa) with respect to the additives percentages. RHA was also found to be effective in increasing the shear strength of CLR–soil mixture.