Dynamic Compressive Behavior of CFRP-Confined High Water Material

As mining operations extend deeper underground, support structures are increasingly subjected to severe impact loads. The dynamic mechanical performance of column-type support systems has, therefore, become a pressing concern. In the present research, a Split Hopkinson Pressure Bar (SHPB) apparatus, combined with Scanning Electron Microscopy (SEM), is used to systematically examine how the water-to-cement ratio, number of carbon-fiber reinforced polymer (CFRP) layers, and strain rate influence the dynamic compressive behavior and microstructural evolution of CFRP-confined high-water material. The results indicate that unconfined specimens are strongly strain rate-dependent, with peak strength following a rise–fall trend. A lower water–cement ratio results in a denser internal structure and improved strength. Additionally, CFRP confinement markedly enhances peak strength and impact resistance, refines failure modes, and promotes the formation of denser hydration products by limiting lateral deformation. This confinement effect effectively mitigates microstructural damage under high strain rates. These findings clarify the reinforcement mechanism of CFRP from both macroscopic and microscopic perspectives, offering theoretical insights and engineering references for the design of impact-resistant support systems in deep mining applications.