HUSK

Soil stabilization refers to the process of improving the engineering properties of soil through physical, chemical, or mechanical means to make it more suitable for construction purposes. In this study, the geotechnical properties of lateritic soil collected from the Ovia North East Local Government Area of Edo State were evaluated to determine the effect of rice husk ash (RHA) as a stabilizing agent. The study was prompted by observed pavement and foundation failures within the study area, which were attributed to the poor strength and instability of the underlying lateritic soils. Rice husk ash, an agricultural waste generated from the combustion of rice husks, was utilized in this research to promote sustainable waste management while improving soil performance. The soil samples were mixed with varying proportions of RHA at 2%, 4%, 6%, 8%, and 10% by dry weight of soil. Laboratory tests including sieve analysis, specific gravity, Atterberg limits, compaction, and California Bearing Ratio (CBR) tests were conducted to evaluate the impact of RHA on the soil’s mechanical and index properties. Results showed that the inclusion of RHA led to improvements in the maximum dry density (MDD) and optimum moisture content (OMC), with noticeable increases in CBR values compared to the untreated samples. However, the results also indicated that RHA alone exhibits limited potential as a stabilizing material at higher percentages. The optimum performance was recorded at 5% RHA content, which provided the best balance between strength and workability. Therefore, the use of 5% RHA is recommended for field stabilization of lateritic soils intended for pavement sub-base construction. Furthermore, to achieve better pozzolanic activity, it is advised that RHA used for stabilization be calcined at a controlled temperature range of 600°C to 700°C, as supported by Alabi et al. (2015)