UTILIZATION OF FLY ASH ACTIVATED BY CEMENT FOR PAVEMENT SUBGRADE

The performance of pavement is very responsive to the characteristics of the soil subgrade. For that reason, weak subgrade is enhanced by adopting the most efficient stabilization technique. Stabilization with fly ash activated with cement was found to be an effective option for improvement of soil properties. Expansive soil treated with varying percentages of fly ash, 0%, 5%, 10%, 15% and 20% combined with 0%, 2%, 4%, 6%, 8% cement content. The experimental results show that addition of cement-fly ash admixture to the soil has great influence on its properties. The effectiveness of the use of waste fly ash (FA) and cement (OPC) in the stabilization of subgrade soils and the reasons likely to influence the degree of stabilization were investigated. Incorporating waste fly ash (FA) and cement (OPC) as additives leads to significant environmental and economic contributions to soil stabilization. This study involves laboratory tests to obtain the Atterberg limit, free swell index (FSI), the unconfined compressive strength (UCS), the California bearing ratio (CBR). Expansive soils pose significant challenges in construction due to their tendency to swell and shrink with changes in moisture content, leading to structural damage and instability. Optimum mix proportions are identified based on the desired engineering properties and environmental considerations. Moreover, the use of fly ash and cement as stabilizing agents offers a sustainable solution by utilizing industrial by-products and reducing the demand for natural resources.