Microbially induced carbonate precipitation for soil improvement: factorial analysis, shear testing and characterisation

Soil improvement utilising microbially induced calcite precipitation technologies is currently attracting a lot of attention in the geo-environmental and geotechnical fields. The purpose of this study is to evaluate how critical parameters influence calcite precipitation, and ensuing improvement in the mechanical characteristics of very loose fine sand. The impact of curing period, soil saturation level, and cementation solution molarity on calcite precipitation are evaluated using a 24 factorial experimentation design. Direct shear tests were conducted to evaluate strength and deformation characteristics. Microstructural characterisation was performed using scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. The effect of any given factor is influenced by the level of other factors indicating that interaction effects also influence calcite produced. MICP offers a promising avenue to address soil. Related challenges include reducing the environmental impact of traditional stabilisation methods as demand for environmentally conscious soil stabilisation techniques grows.