Comparative Evaluation of Stabilized Soil Properties Incorporating Bagasse Ash with Cement Vs Lime on Determination of Best Additive Combinations

Abstract

This study investigated the use of bagasse ash from Custus arabicus L. as a pozzolanic admixture for stabilizing expansive black cotton soil alongside cement and lime. Samples of the problem soil were collected and treated with varying proportions (2.5-10% by dry weight) of bagasse ash in combination with a constant 8% content of cement or lime. The engineering properties of the treated composites such as maximum dry density, optimum moisture content, consistency limits, California bearing ratio and unconfined compressive strength were evaluated based on standard procedures. The results showed that both the cement-bagasse ash and lime-bagasse ash composites were effective in modifying the expansive behavior and improving the strength of the black cotton soil. Key indicators like liquid limit, plastic limit and plasticity index decreased with rising bagasse ash content, indicating a reduction in soil shrink-swell potential. Meanwhile, properties enhancing load-bearing capacity such as maximum dry density, optimum moisture content, CBR and UCS values increased upon treatment. Among the mixtures, soil stabilized with 8% cement and 7.5% bagasse ash composite exhibited the optimal performance. Compared to untreated soil, maximum improvements of 66.4% and 102.6% were recorded in the CBR and UCS values respectively for the optimal cement-bagasse ash blend. Overall, both lime and cement-based composites incorporating bagasse ash from Custus arabicus L. showed potential for modifying expansive subgrades and increasing their structural capacity. The study established the viability of utilizing agro-industrial waste alongside conventional stabilizers for ground improvement works.