Stabilization of laterite soil using reclaimed asphalt pavement and sugarcane bagasse ash for pavement construction

A laboratory study was carried out to evaluate the strength of laterite soil stabilized with recycled asphalt pavement (RAP) and sugarcane bagasse ash (SCBA). The laterite soil was mixed with RAP in 40/60 ratio and treated with SCBA at 0, 2, 4, 6, 8 and 10 % by weight of the soil-RAP mixture. Particle size analysis, compaction test, unconfined compressive strength, (UCS), and California bearing ratio (CBR), tests were carried out on the prepared specimens. The results obtained show that addition of RAP reduces the optimum moisture content, (OMC), and increases the maximum dry density (MDD) of the sample as compared with the natural soil while the addition of SCBA up to 4% results in further increase in MDD; further addition of SCBA results in reduced MDD whereas OMC increased with increasing SCBA. UCS and CBR increased with SCBA treatment and curing period respectively. Soaking of the specimens for 24 hours results in reduced CBR values. Based on the laboratory results obtained and based on the strength criteria for soil-lime adopted in this study, it was observed that 6 to 8% SCBA treatment of the soil-RAP mixture yielded the best results meeting the requirement for sub base course and 10% SCBA treatment gives the best results meeting the requirement for base course for light trafficked roads.