Effect of cement and sugarcane bagasse ash on the micro-mechanical characteristics of expansive soil
Shantanu Paul, Promita Chakraborty, Arzida Binta Anwar, Golam Mortoza, Laila Sharmin Sukti
Abstract
Expansive soils, which undergo significant volume changes due to moisture fluctuations, pose serious challenges for construction. This study investigates the effectiveness of using cement and sugarcane bagasse ash (SBA) to improve the mechanical properties and volumetric stability of such soils. A series of laboratory tests including unconfined compressive strength (UCS), split tensile strength (STS), California bearing ratio (CBR), one-dimensional swell test, and free swell index (FSI) assessment were conducted. The results demonstrate that SBA can effectively replace a portion of cement, contributing meaningfully to soil stabilization. The stabilized soil showed remarkable performance enhancements. UCS and STS increased by up to 1380% and 1166%, respectively, while the optimized CBR value improved by 2450%. Additionally, swell strain and swell pressure were reduced by up to 98% and 89%, and a significant decrease in FSI was observed. The best results were achieved with 4% SBA by weight, offering a cost-effective and environmentally friendly alternative to full cement usage. SEM and FTIR analyses confirmed the formation of calcium silicate hydrate (C-S-H) and the contribution of pozzolanic reactions to the improved soil structure. Overall, the study underscores the potential of SBA as a sustainable stabilizer for expansive soils in moisture-sensitive environments.