Impact characteristics of high-performance steel fiber reinforced concrete under repeated dynamic loading

An experimental study on the impact performance of silica fume concrete and steel fiber reinforced con crete at 28 days and 56 days under the action of repeated dynamic loadin g was carried out. In this experimental investigati on, w/cm ratios of 0.4 and 0.3, silica fume replacement at 10% and 15% and crimped steel fibers with an aspect ratio of 80 we re used. Results indicated that addition of fibers in high-performan ce concrete (HPC) can effectively restrain the init iation and propagation of cracks under stress, and enhance the impact strengt hs, toughness and ductility of HPC. Pulse velocity test was carried out for quality measurements of high-performance steel fibe r reinforced concrete. Steel fibers were observed tsignificant effect on flexural strength of concrete. The maximum first crack strength and ultimate failure strength at 28 days were 1.51 times and 1.78 times, respectively at 1.5% volume fraction to that of HPC. Based on the experimental data, failu re resistance prediction model was developed with correlation coefficient (R ) = 0.96 and absolute variation determined is 1.82% .