The Dynamic Compressive Behavior of Waved Fiber-Reinforced Ultrahigh-Performance Cementitious Composites Containing Fly Ash and Ground Granulated Blast-Furnace Slag

Abstract

The dynamic behavior of ultrahigh-performance cementitious composite (UHPCC) structures under impact loads is a topic of great importance because such loads usually cause severe structural damage, which may impose potential hazards to the personnel and facilities protected by the UHPCC structure. In the present work, a new UHPCC was developed, and five kinds of UHPCC specimens with different fiber types and fiber content were prepared. A series of impact compression tests were conducted by using a split Hopkinson pressure bar system to study the dynamic properties of different types of UHPCC in the strain rate range of 50–180 s−1. The dynamic compressive strength, peak strain, failure pattern, and dissipated energy were obtained and analyzed to reveal the effects of steel fiber type and content on the impact resistance of UHPCC, and the waved steel fiber reinforcement mechanism was also discussed. In addition, two indexes, i.e., the critical strain rate and the energy absorption efficiency, were introduced to evaluate the impact resistance of UHPCC materials. It is interesting to find that the maximum energy absorption efficiency is the same for all types of UHPCCs (equal to 0.47) and the strain rate when the maximum energy absorption efficiency is reached is almost identical with the critical strain rate.