Microscopic damage and strengthening mechanisms of honeycomb-structured scaffold reinforced cementitious materials: Experimental and numerical investigation

Abstract

Compressible energy-absorbing materials can reduce the surrounding rock pressure borne by support structures through collapse deformation, providing an effective solution for controlling large deformation hazards in deep tunnels and roadways. In this study, a novel compressible material—honeycomb-structured scaffold reinforced cementitious material (HSRCM)—was developed by integrating a 3D-printed multilayer deformable honeycomb scaffold with a cementitious matrix. The macroscopic and microscopic mechanical properties of HSRCM were investigated through experiments and discrete element simulations, revealing the reinforcement mechanism of the honeycomb scaffold. Results indicate that increasing scaffold volume enhances the initial peak load and strain-hardening behavior, while significantly improving energy absorption capacity by 131–175 %. Digital image correlation analysis revealed a negative correlation between global strain rate and scaffold volume. Finally, a discrete element model of HSRCM was constructed to validate the skeletal reinforcement effect of the honeycomb scaffold and to clarify the load-bearing interactions among the matrix, scaffold, and interface under compressive loading.