Experimental study on the macroscopic and microscopic mechanical properties of simulated cemented granular materials

As solid matrices can bond with other materials and enhance the mechanical properties of engineering structures, investigating the mechanical properties and cementation mechanism of cemented granular materials has become increasingly significant. However, most experiments were conducted only at macroscopic or microscopic levels. Further, it is difficult to compare and analyze the results at macroscopic and microscopic levels because of the complex spatial and mechanical effects between cemented particles at the mesoscale. In this study, we created a well-defined cohesive granular material with controllable cementation held together by mixing glass beads and a solid matrix. First, we explored the influence of the confining pressure and solid matrix content on the mechanical strength of the cemented granular materials through a consolidated undrained triaxial compression test to address the cementation effect quantitatively. Second, through tensile and shear tests on cemented units with different matrix volumes, the cementation mechanism of the cemented units was explored for the first time from the perspective of the stress-strain relationship. Finally, we qualitatively explained the mechanical phenomena of macroscopic cemented granular materials through the microscopic interaction between particles and realized a multi-scale analysis of the mechanical response of cemented granular materials, which may provide new ideas for the study of cemented granular materials.