Investigation of the Effect of Sporosarcina pasteurii Bactria on the Microbial Induced Carbonate Precipitation (MICP) and the UCS of carbonate Sands

Fast growing of engineering infrastructure to meet human requirements is directly related to the need for a resistant soil to carry out construction load. On the other hand, the importance of environmental issues has led to an ever-increasing demand for new and environmentally friendly methods for soil remediation. The method of microbial induced calcium carbonate precipitation (MICP) is considered by the researchers as one of the most environmentally friendly methods. The purpose of this study was to investigate the effect of MICP on the uniaxial strength of carbonate sand. Therefore, samples of Bushehr carbonate sand were cured after the injection of bacteria and cement solution. Then a uniaxial compression tests were carried out to evaluate the compressive strength. Also, the effect of cement solution concentration and curing time on the results of MICP method was investigated. The results show that maximum uniaxial strength of sand stabilized with MICP is about 3.5 kg/cm2, which indicates the proper performance of MICP method for stabilization of carbonate sand. The UCS of the samples depends on the concentration of cement solution. Stabilized samples with a higher cementation of concentration solution had more uniaxial resistance than samples with lower cement concentrations. The curing time more than 14 days did not significantly affect the uniaxial resistance.