Expansive Soil Stabilization by Bagasse Ash in Partial Replacement of Cement

Abstract

This study examined the effects of using bagasse ash in replacement of ordinary Portland cement (OPC) in the treatment of expansive soils. The study concentrated on the compaction characteristics, volume change, compressive strength, splitting tensile strength, microstructure, California bearing ratio (CBR) value, and shear wave velocity of expansive soils treated with cement. Different bagasse ash replacement ratios were used to create soil samples. At varying curing times of 7, 14, and 28 days, standard compaction tests, unconfined compressive strength tests, CBR tests, Brazilian split tensile testing, and bender element (BE) tests were carried out. According to X-ray diffraction (XRD) investigations, quartz and crystobalite make up the majority of the minerals in bagasse ash. Bagasse ash contains a variety of grain sizes, including numerous fiber-shaped particles, according to a scanning electronic microscope (SEM) test. For all of the treated specimens with various replacement ratios, the overall additive content has not changed. The results of the Brazilian split tensile tests demonstrate improved tensile strength for all specimens with various replacement proportions. A lower maximum dry density and a greater optimal water content would result from the substitution of bagasse ash. When the replacement ratio is not more than 20%, the CBR values of the parts replaced specimens are even higher than the cement treatments. The results of BE testing on the treated soils show that there is significant stiffness anisotropy but that it steadily diminishes with curing time and replacement ratio. According to the study, bagasse ash is a useful mineral additive, and the best replacement ratio (CBA20) is 20%.