Exploring an environmentally friendly microbially induced calcite precipitation (MICP) technology for improving engineering properties of cement-stabilized granite residual soil

This study explored Microbially Induced Calcite Precipitation (MICP) technology to improve the engineering properties [i.e., unconfined compressive strength (UCS)] of granite residual cemented-soil through calcite precipitation. The influence of age and cement mixing ratio on strength, stiffness and the stress-strain relationship of MICP induced calcite precipitation in granite residual cemented-soil was investigated. Scanning electron microscope (SEM) was used to analyse the microstructure characteristics of the cemented-soil. Based on the results, the cemented granite residual soil reinforcement mechanism was proposed. The following conclusions were obtained: (1) MICP technology can significantly enhance and improve the engineering properties such as strength, stiffness and toughness of cemented-soil. Compared with the control group, the maximum growth rate of the test group was 87.5%, and the maximum growth rate of the elastic modulus was 141.18%; (2) Soil particles were cemented through MICP technology, making the cemented-soil surface denser; (3) The MICP technology makes the cemented-soil treatment method more sustainable for its use in improving the stability of geo-structures.