Cavitation erosion behavior of high-performance fiber-reinforced cementitious composites

Cavitation erosion poses a significant challenge in the durability design of spillway lining concrete. With the advent of low-carbon, high-performance cementitious composites, traditional concrete is increasingly being replaced by high-performance fiber-reinforced cementitious composites (HPFRCC). However, the cavitation erosion performance of these novel materials remains largely unexplored. This study systematically investigates the cavitation erosion behavior of HPFRCC and high-strength mortar through ultrasonic cavitation erosion tests. HPFRCC is reinforced with steel fibers and comprises a quaternary cementitious matrix that includes three types of solid waste materials along with titanium slag sand. The findings demonstrate that HPFRCC exhibits lower volume/mass loss, reduced loss rates, smaller fractal dimensions, and a slower rate of erosion depth development compared to mortar. Furthermore, the presence of steel fibers and the enhanced strength of the matrix result in a distinct cavitation erosion evolution process in HPFRCC relative to mortar. The incorporation of steel fibers effectively slows the rate of erosion depth development, while the fiber-matrix interface performance and fiber orientation significantly influence the efficacy of the steel fibers. Additionally, a positive correlation exists between the compressive strength of both HPFRCC and mortar and their resistance to cavitation erosion. However, when the compressive strength exceeds 140 MPa, the effect of compressive strength on the cavitation erosion resistance of cement-based composites diminishes significantly. The findings reveal the superior cavitation erosion resistance of HPFRCC, providing practical insights for the further application of novel cementitious materials.