Assessment of strength and low-strain shear modulus of bio-cemented sand considering MICP treatment

Bio-cementation of natural sand is a prospective solution to improve their engineering properties. The enhancement of strength and low-strain shear modulus is considered to be of high engineering significance for improvement in the performance of sand under both static and dynamic loading. In the present study, bio-cementation effects of bacillus Sporosarcina pasteurii bacteria on standard Ennore sand of India are studied at the microstructure level through scanning electron microscope (SEM) investigation considering microbial-induced calcite precipitation (MICP) technique. The crystallographic structure of the bio-cemented sand is reported through X-ray diffraction (XRD) analyses. Stress-strain behaviour and improvement in the strength of bio-cemented sand with different pore volumes of cementation solution have been investigated through unconfined compression strength (UCS) testing. Finally, the shear wave velocity values of the bio-cemented sand are assessed through bender element testing for different confining pressures, and low-strain shear modulus values have arrived. The study is believed to be helpful in the quantification of improvement of strength and low-strain shear modulus values of bio-cemented sand.