Effect of Bagasse Ash on Lime Stabilized Lateritic Soil

This study was carried out to evaluate the effect of bagasse ash (BA) on lime stabilized lateritic soils. Laboratory tests were performed on the natural and lime/bagasse ash treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990), respectively. Treated specimens were prepared by mixing the soil with lime and/or bagasse ash in variations of 0, 2, 4, 6 and 8% by weight of the soil. The preliminary investigation carried out on the natural lateritic soil found in Shika, Kaduna State, Nigeria shows that it falls under SiltClay material of Group A-6(9) using AASHTO classification and inorganic clay material CL according to Unified Soil Classification System (USCS). The natural soil has a liquid limit value of 36.32, a plastic limit of 21.30% and a plasticity index value of 15.02 %. The maximum dry density (MDD) of the soil was 1.69 kg/m3 and an Optimum Moisture Content (OMC) value of 16.8 %. Unconfined compressive strength (UCS) values of 269, 404 and 591 kN/m2 at 7, 14 and 28 days curing periods, respectively, were recorded for the natural soil. Unsoaked and soaked California Bearing Ratio (CBR) values of 13 and 7%, respectively, were recorded for the natural lateritic soil. Peak UCS and CBR values of 698 kN/m2 and 43% were recorded for soil treated with 8% lime/6% bagasse ash. The peak CBR value met the 20 ? 30 % requirement for sub-base reported by Gidigasu and Dogbey (1980) for materials compacted at optimum moisture content, while the peak UCS value fell short of the 1710 kN/m2 unconfined compressive strength value specified by by Transport and Road Research Laboratory (TRRL) (1977) as a criterion for adequate stabilization using ordinary portland cement.