Dynamic splitting behavior of microcapsule-based self-healing cementitious composites under SHPB impact loading

Abstract

This study presents an experimental study on the dynamic splitting tensile performance of microcapsule-based self-healing cementitious composites and fiber-reinforced microcapsule cementitious composites. The research aims to determine the effect of microcapsule dosages, fiber types, and strain rates on the dynamic splitting tensile behavior of materials. A total of 99 specimens were subjected to the split Hopkinson pressure bar (SHPB) impact loading within the strain rates of 0.85–17.12 s−1. A high-speed camera was employed to capture the crack propagation process, and scanning electron microscopy (SEM) was used to characterize the corresponding microstructure. The results indicated that the splitting tensile performance of materials exhibits significant strain rate sensitivity. The addition of microcapsules increases the dynamic splitting tensile strength of the material, and the highest energy absorption capacity can be achieved with a 5 % microcapsule dosage. The incorporation of polyvinyl alcohol (PVA) and polyethylene (PE) fibers effectively enhances dynamic splitting tensile strength and energy absorption capacity, achieving optimal performance with the incorporation of PVA-PE hybrid fibers. Furthermore, the investigation of the dynamic increase factor (DIF) of the material indicates that fibers heighten the strain rate sensitivity of the material.