Effect of used oil contamination and bagasse ash on some geotechnical properties of lateritic soil

摘要

This study was carried out to evaluate the effect of used oil contamination and bagasse ash on some geotechnical properties of northern Nigerian lateritic soils. Laboratory tests were performed on the natural/oil contaminated and bagasse ash treated contaminated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively. Contaminated specimens were prepared by mixing the soil with oil in steps of 0, 2, 4, and 6 % by weight of the soil while bagasse ash treated specimens were prepared by mixing the oil contaminated soil with bagasse ash in steps of 0, 2, 4, 6 and 8 % by weight of dry soil. The soil is of Group A-6 using AASHTO classification and CL according to Unified Soil Classification System (USCS). The plasticity index of the soil decreased from 15.02 % for the natural soil to 8.16 % at 6 % oil/8 % bagasse ash content. The maximum dry density (MDD) of the soil increased from 1.48 Mg/m³ for the natural soil to peak value of 1.60 and 1.62 Mg/m³ at 6 % oil content and 6 % oil/8 % bagasse ash content.. The Optimum Moisture Content (OMC) decreased from a value of 18.5 % for the natural soil to 13.0 and 11.3 % at 6 % oil content and 6 % oil/8 % bagasse ash content. Volumetric shrinkage test was first performed on the soil specimens at their respective optimum moisture contents and then repeated at +2 % and -2 % of the optimum moisture contents. It was observed that used oil and bagasse ash have no adverse effect on the maximum dry density and volumetric shrinkage of lateritic soil when compacted at optimum moisture content or dry of the optimum moisture content.