Experimental Study on the Strength of Concrete Joint Reinforced by Microbially Induced Calcium Carbonate

Abstract: The microbially induced calcium carbonate precipitation (MICP) technique is a developing soil and rock reinforcement technique. In order to improve the reinforcement influence of MICP on concrete joints in a saline-alkaline environment, direct shear tests on concrete cracked samples reinforced by microbially induced calcium carbonate were conducted. The strengthening effects of Sporosarcina pasteurii on the shear strength of concrete joints were comprehensively evaluated. Samples of sandstone with rough surfaces were prepared and reinforced by MICP. The shear strength characteristics of rock joints reinforced by CaCO3 were then deeply assessed by laboratory tests. The results showed that the acclimated Sporosarcina Pasteurii has good reinforcement performance in saline-alkaline conditions. In the saline-alkaline environment, the shear strength of concrete joints repaired by microbially induced calcium carbonate significantly increased. The ultimate shear-strength concrete joint reinforced by MICP rose with the curing time, but its strength developed quickly in the early stage and slowly in the later stage of the experiment. The peak shear strength of cemented concrete joints increased significantly compared to uncemented concrete joints. The current research idea could be a benchmark for applying the MICP technique in repairing the joints of concrete.