Efficiency of Bagasse Ash Incorporated With Limestone Calcined Clay Cement on Improvement of Geotechnical Properties of Black Cotton Soils: A Cleaner Approach

This study is aimed at investigating the effect of sugarcane bagasse ash (BA) incorporated with limestone calcined clay cement
(LC3) as potential alternative from technical, ecological and economic perspectives of black cotton soil (BCS) stabilisation. BA
incorporating LC3 material was added to BCS having high swell degree, in mix proportions of 0%–18%. Series of laboratory
tests were conducted in terms of free swell index (FSI), compaction, unconfined compressive strength (UCS), California
bearing ratio (CBR) and shear strength engineering properties. Besides, microstructure changes were evaluated in terms of pore
size distribution (PSD), x-ray diffraction (XRD) and scanning electron microscope (SEM) to analyse factors responsible for
performance improvement of stabilised BCS. Results indicated that BA incorporating LC3 binder stabilisation completely
eradicated swelling behaviour and improved strength performance of BCS. FSI reduced by 71.8%, UCS increased and CBR
performance attained 80% threshold, complying with requirements for foundation soil road applications. Shear strength and
cohesion increased with increase in binder content and curing period. Performance of 12% BA incorporating LC3 binder
additive content to BCS was found to have highest internal friction angle. Microstructure evaluations showed that calcium
aluminosilicate hydrates (CASHs) are prime cementitious products formed behind stabilised BCS. Analysis pertaining to
carbon footprint and cost indicated that BA incorporating LC3 binder is a more cleaner and cost-effective construction
material. This study promotes application of BA incorporating LC3 binder technique for BCS treatment in pursuit to mitigate
current climate change emergency and reduce high cost encountered during routine BCS stabilisation practice.