Understanding the Engineering Behaviour of Expansive Soil Amended with Bagasse Ash and Lime Using Microstructural Analysis

Overburden of industrial waste is a geoenvironmental concern, and its utilization in revamping the properties of expansive clays is an adoptable sustainable solution. Processed left outs from sugarcane based industries generates bagasse ash (BA) in voluminous amounts, the same can be used to detain the volume change attributes of the expansive soil which is presented in this paper. The bagasse ash was added to the expansive soil in increasing percentages by weight ranging from 0 to 20%. The parameters that are vital for the stabilisation criterion were assessed even with the presence of lime. Because it is necessary to lessen the effects of the expansive soil’s repeating wetting–drying phenomena, wetting–drying cycles tests were also conducted on the expansive soil blended with bagasse ash, both by itself and in combination with lime. The reactivity between additives and the expansive soil was examined through powdered X-ray diffraction, field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS) along with Fourier transform infrared (FTIR) analyses. Based on the analysis of the experimental results, it was found that the bagasse ash helped in particle adhesion and pozzolanic reaction initiated in the presence of lime helped in attaining dense micro structure which was evident from FESEM images. This proved that ternary blends (expansive soil, bagasse ash and lime), are more effective when compared to binary blends of BA and expansive soil. The addition of 5% of lime and 15% of bagasse ash was found to be a more effective sustainable solution in combating the volume change attributes of the black cotton soil.