Synergestic effect of rice husk ash blended with cement on the stabilization of lateritic soil for road construction

Lateritic soils are widespread in tropical regions and are often unsuitable in their natural state due to their high plasticity and low strength. Although Portland cement has been used for soil stabilization over time, its heightened environmental concernsdue to carbon emissions from its production have led to the need for alternatives. This study, therefore, aimed at investigating the effects of stabilization of Lateritic soil with Rice Husk Ash (RHA) blended with cement for highway application. Oxide compositions of lateritic soil obtained from Aroje, Ogbomoso, Nigeria and RHA were determined using X-Ray Fluorescence (XRF) Spectrophotometer. Natural Moisture Content (NMC), Percentage passing sieve No. 200 (P-200) Liquid Limit (LL), Plastic Limit (PL), Plasticity Index (PI), Optimum Moisture Content (OMC), Maximum Dry Density (MDD) California Bearing Ratio (CBR), and Unconfined Compressive Strength (UCS) were determined for the lateritic soil after it had been admixed with varying proportions of Portland Lime Cement (PLC) (5, 10 and 15%) and RHA (2, 4, 6, 8 and 10%) by dry weight of soil to evaluate the best mix for the stabilization. The SiO2, Al2O3and Fe2O3contents in the lateritic soil and RHA were 58.057, 18.212and 13.620%,and 84.195, 2.819 and 0.863%, respectively. The NMC, PI and P-200 of natural soil were 10, 50 and 32.76%. The LL, PL, PI, MDD, CBR, and UCS of stabilized soil ranged 25.0 -31.50, 25.0 –29.3.0, 0 -3.5, 7.95 –10.81%, 1.84 -1.960 g/cm3, 76 -94 and 186 -334 kPa, respectively. There was a good improvement in the strength properties of lateritic soil using 10 as the best mix of cement and RHA and this can be used as a subbase and base material in road construction