Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

Abstract

Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste powders. The dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB). The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity method. Results show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume fraction. The stress waves on impact were recorded and the average stress, strain and strain rate of UHPCC were calculated based on the wave propagation theory. The effects of strain rate, fibers volume fraction and impact times on the stress-strain relations of UHPCC were studied. Results show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.