The Cementation Mechanisms and Mechanical Properties of Different Soil–Rock Mixtures–Slurry Cements

This investigation focused on the cementation mechanisms and mechanical properties of soil-rock mixtures-slurry cement (SRM-SC) to ensure the safety of tunnels during operation. SRM-SC specimens were prepared with different types of slurry and rock contents based on an actual slurry injection ratio. The macroscopic level analysis involved measuring the specimens' uniaxial compressive strength and shear strength, determining the strength parameters, and analyzing the damage forms. At the microscopic level, the surface morphology and composition of the specimens were examined using scanning electron microscope imaging. This allowed for a comparative analysis of the cementation ability and mechanism of the slurry under different control conditions, providing a basis for determining the mechanical properties of SRM-SC. The results indicated that the rock content significantly impacts the macromechanical properties of SRM-SC. The compressive strength and stiffness of SRM-SC initially increase and then decrease with the increasing rock content, with an inflection point observed between a 20% and 60% rock content. On the other hand, the shear strength and stiffness both increase with the increasing rock content. Additionally, the macroscopic mechanical properties of SRM-SC formed by different types of grout exhibit noticeable differences. These findings serve as a reference for regulating the mechanical properties of SRM-SC.