Effects of lime treatment on geotechnical properties and diesel contamination of laterite soils

This study investigated the effects of lime treatment on geotechnical properties of a lateritic soil contaminated with diesel contents of 0%, 3%, 6%, 9%, and 12%. The control laterite and the diesel-contaminated laterite were treated with lime in the ranges of 0%, 3%, 6%, and 9%. The results showed that diesel contamination adversely affected soil properties. At 12% diesel-contamination, the liquid limit (LL) and plastic limit (PL) increased by 38.3% and 16% respectively. The maximum dry unit weight (MDUW) reduced by 7.85%, while the optimum moisture content (OMC) increased by 46.9%. The California Bearing Ratio (CBR) and unconfined compressive strength (UCS) decreased by 46% and 42.93%, respectively. However, lime treatment significantly improved geotechnical properties of the diesel-contaminated soil. At 9% lime content, the liquid limit and plastic limit of the contaminated soils were improved to suit the soil’s requirements for use in geotechnical applications such as roads and embankments construction. Moreover, the dry density increased while the optimum moisture content reduced. Peak CBR (13.7%) and UCS (421 kN/m²) were observed at 6% lime content, while a decline in strength was observed at 9% lime content. Overall, lime reduced the liquid limit by 8.3%, increased the plastic limit by 11.6%, and significantly enhanced CBR and UCS properties of the diesel-contaminated lateritic soil. Therefore, lime treatment can restore pertinent engineering properties of diesel-contaminated soils for geotechnical applications.