Low-velocity impact tests on self-compacting concrete prisms

Several structural members like columns and walls can be under the effect of accidental strikes from falling objects or collision of moving vehicles. Several researches are available in the literature on impact tests on different types of concrete, while those on Self-Compacting Concrete (SCC) reinforced with steel fiber are very limited. In this research, repeated impact tests were conducted on normal strength and high strength SCC reinforced with micro-steel fibers. Four fiber fractions of 0, 0.5, 0.75 and 1.0% by volume were investigated, while two design strength of 30 and 50 MPa were considered as normal and high strength SCCs. The test procedure was similar to the repeated impact test technique of ACI 544-2R but with a drop height of 100 mm and using prism specimens. The test results showed that micro-steel fiber can increase the impact resistance of SCC significantly. The inclusion of 1.0% fiber led to up to approximately 500% increase in the retained number of impacts at cracking stage, while the percentage increase at failure was much higher which reached approximately 2100%. On the other hand, the adopted high strength SCC could retained only up to approximately 30% higher number of impacts compared to normal strength SCC.