Caroline Tereza Aber2024-04-192024-04-192024-04-17https://hdl.handle.net/20.500.12311/1353This study examines the engineering properties of silty clay soils and their improvement through stabilization with hydrated lime and rice husk ash (RHA). Initial findings show untreated silty clay has poor load-bearing capacity and high plasticity, unsuitable for subgrade applications. Chemical analysis confirms RHA meets ASTM C 618-2012 standards, with SiO2 + Fe2O3 + Al2O3 content exceeding 70%. Optimal stabilization with 4% lime and 8% RHA enhances soil properties: reducing plasticity index, increasing CBR from 8% to 35%, and surpassing UCS requirement (0.5 MPa). Lime-RHA treatment yields a Compression Index (Cc) of 0.23 and Recompression Index (Cr) of 0.06, improving load-bearing capacity. Soil shows suitability for stabilization with low free swell index (2.3%), negligible moisture, slightly alkaline pH, moderate density (1.52), and low electrical conductivity. Further RHA addition (12%) decreases CBR and UCS, emphasizing stabilizer balance. In conclusion, combined lime-RHA application offers a promising method for subgrade construction, enhancing soil strength, reducing water sensitivity, and potentially improving drainage.enDissertation