Single and multiple dynamic impacts behaviour of ultra-high performance cementitious composite

Abstract

Single and multiple dynamic impacts tests were conducted on ultra-high performance cementitious composite (UHPCC) with various volume fractions of steel fibers (0, 1%, 2%, 3%, 4%) by using the split hopkinson pressure bar (SHPB). Besides, the ultrasonic velocity method was used to test the damage on specimens caused by dynamic impacts. For single dynamic impact, the data suggest that UHPCC obviously presents dynamic strength enhancement. With increasing of strain rate, the peak stress and peak strain increase rapidly. For multiple dynamic impacts, the results show that addition of steel fibers can obviously enhance the properties of UHPCC to resist the repeated dynamic impacts. Firstly, the number of impacts sharply increases with the increasing of volume fraction of steel fibers. Secondly, the energy absorption ability linearly increases with addition of steel fibers. Thirdly, the steel fibers can prevent the disruption phenomenon and maintain the integrity of specimen.