Uniaxial Compression Behavior and Energy Evolution of Joint Rock Repaired and Reinforced with Biocementation Method

Rock joints should be improved to gain higher strength and stability for construction. Enzyme-induced carbonate precipitation (EICP) represents a novel environmentally friendly biocementation methodology. In this study, crude urease was extracted from soybeans in the laboratory, and the EICP technology and the filling mediums were employed to reinforce the pre-existing fissure sandstone. The effects of EICP on the uniaxial compressive stress–strain behavior, failure mode, and energy evolution of pre-existing fissure sandstone were investigated using four different urease mass concentrations and three filling mediums. The result showed that the combined filling effect of the two mixtures is more pronounced than that of sandstone grinding particles or polyvinyl alcohol (PVA) fiber alone. An increase in the urease mass concentration results in a reinforcement of the strength of pre-existing fissure sandstone that has been reinforced by EICP technology and filling mediums. In comparison to the uniaxial compressive strength prior to and following reinforcement, there has been a notable increase of 103.05%. Furthermore, the failure mode shifts from shear failure to tension failure, accompanied by an enhanced energy absorption capacity and brittleness. Nevertheless, the phenomenon of pre-peak energy dissipation is observed to increase, while the energy storage coefficient shows a decline. This study broadens the scope of EICP technology applications and presents a novel approach to reinforce rock joints.