Lime-stabilisation of high plasticity swelling clay from Ethiopia

AbstractIn the present study, highly expansive clay soils from the Highlands of Ethiopia were studied to evaluate the efficiency of lime treatment to improve their mechanical properties for road subgrades. Soils treated with quick lime at 5, 7 and 9% by dry weight of the soil were cured for seven days under controlled temperature of 40 ± 2 °C and geomechanical laboratory tests were conducted to evaluate its impact on the engineering properties of the soil. Test results show substantial improvements in the properties of the soil after lime treatment. Addition of lime significantly reduces the plasticity index and swelling potential of the soil. Similarly, despite the reduction of optimum proctor dry density due to lime treatment, the unconfined compressive strength and the California bearing ratio show considerable improvements. Based on the current study, expansive soils of the studied area can be effectively stabilised for road subgrade works with the addition of 7% quick lime by dry weight of the soil. ...