Mechanical performance evaluation of steel fiber-reinforced concrete (FRC) based on multi-mechanical indicators from split hopkinson pressure bar (SHPB) test

Fiber-reinforced concrete (FRC) is a new composite material composed of various fibers and a cement matrix that has been widely used and developed in the construction engineering field. In this paper, split Hopkinson pressure bar (SHPB) tests are carried out with the aim of investigating the mechanical properties and failure characteristics of FRC containing different types and dosages of steel fibers. The main findings are as follows: At a fiber content of 0 %-3.5 %, the strength of FRC shows two trends: continuously increasing and then decreasing. The ductility of hookedend steel fiber-reinforced concrete (HFRC) is better than that of hybrid steel fiber-reinforced concrete (HSFRC) and straight steel fiber-reinforced concrete (SFRC) under static loads, whereas the ductility of HSFRC is better than that of SFRC and HFRC under dynamic loads. Straight steel fibers (SF) are better than hooked-end steel fibers (HF) in improving tensile toughness but worse than HF in improving compressive toughness. In terms of the degree of failure, NFRC and HFRC were the most severely fragmented, whereas SFRC and HSFRC exhibited better integrity. Finally, based on the multi-mechanical indicators of the FRC, a comprehensive performance evaluation method and optimization suggestions for the FRC are proposed. This provides theoretical support for the application of FRC as seismic-resistant materials in reinforced structures (i.e., anti-slide piles, retaining walls, and beam structures) of rocky landslides in strong seismic areas, which have important engineering significance.