Highway Pavement Stabilization of Soil with Costus bracteatus Rowlee and Cement

Abstract

The study investigated the performance of cement and bagasse ash composite as soil stabilizer. The bagasse ash was obtained from Costus bracteatus Rowlee. Lateritic soil samples collected along a newly constructed road in Rivers State, Nigeria were prepared and analyzed for effect of the composite stabilizer on maximum dry density (MDD), optimum moisture content (OMC), consistency limits, California bearing ratio (CBR) and unconfined compressive strength (UCS). The results revealed that swelling potential, volume change MDD, OMC, liquid limit (LL), plastic limit (PL) and plasticity index (PI) of the stabilized lateritic soil decreased with increasing proportion of cement-bagasse ash composite, while CBR (unsoaked and soaked soil samples) and UCS were with increasing proportion of cement-bagasse ash composite. This study established that the optimum proportion of bagasse ash is 8% and that inclusion of an appropriate proportion of bagasse ash in cement in soil stabilization would enhance the properties of soil suitable for road pavement. Therefore, Costus bracteatus Rowlee is recommended to be used in soil stabilization, particularly as composite material.