Split-Hopkinson Pressure Bar Test and Numerical Simulation of Steel Fiber-reinforced High-strength Concrete

The fabrication and optimization of the shelter layer are critical to the performance of the protective works. The novel shelter layer made of steel fiber-reinforced high-strength concrete (SFRHSC) is much more advantageous than that of ordinary concrete. This paper carries out a split-Hopkinson pressure bar (SHPB) test on the steel fiber and high-strength concrete, two main components of the SFRHSC, aiming to disclose the failure features and dynamic compressive strength of the SFRHSC under dynamic conditions. Specifically, the SFRHSC specimens with 0 %, 0.5 % and 1.0 % of steel fiber were subjected to impact compression test under the air pressures of 0.7, 0.9 and 1.0MPa, respectively. In addition, the impact compression process was also numerically simulated on the finite-element software LS-DYNA. The research results show that: the increase in strain rate pushed up the dynamic compressive strength of the SFRHSC, that is, the failure degree of the specimen was greatly enhanced by the strain rate; under the air pressure of 0.7MPa, the specimen with 1.0 % of steel fiber had the highest dynamic compressive strength (180.9MPa), 22.6 % higher than that of the specimen with no steel fiber; the numerical simulation reproduced the one-dimensional (1D) propagation of the stress wave in the bars, which proves the hypothesis of 1D elastic stress wave, and restaged the impact compression process on the SFRHSC, outputting results similar to the test data.