Experimental research on influence of low temperature on MICP-treated soil

The microbially induced carbonate precipitation (MICP) has become an active issue in the field of geotechnical engineering. However, the feasibility and reinforcement effects of this technology at low temperature are not available in previous literatures. A series of tube tests and one-dimesion sand column trials using ureolytic bacteria ATCC11859 are conducted to investigate the influence of ambient temperature on MICP behavior and stabiliszaion effectiveness. The tube test results show that the final amount of calcium carbonate is much more in high temperature than lower temperature, and the temperature has a notable influence on the formation rate of precipitations instead of the morphology of CaCO₃ in aqueous medium. The experiments on coarse sand treated with surface percolation demonstrate the validity of bio-grout at common soil temperature, whereas the MICP-treated sand column has a relatively lower UCS as well as higher permeability coefficient at low temperature.