Tensile Strength and Fracture of Interparticle MICP Bonds

Microbially induced calcium carbonate precipitation (MICP) is a novel cementation technique. The improved responses of biotreated soils are mainly attributed to interparticle MICP bonds and have been extensively studied by element-scale tests. However, the particle-scale mechanism of MICP bonds has not been fully understood, especially when considering the discrepancy in particle morphology. In this paper, we carried out a series of particle-scale tensile tests on biotreated quartz sands and glass beads and found that tensile strength of the MICP bonds increased with an increase in cementation level or a decrease in regularity of particle shape. We also interpreted the statistical distribution of the tensile strength and tensile failure modes. The results of this study could provide a solid base for theoretic modeling of biotreated soils.