An experimental and numerical study on how steel and polypropylene fibers affect the impact resistance in fiber-reinforced concrete

In this paper, impact loading results from numerical simulations of plain concrete (PC) and fiber-reinforced concrete (FRC) are compared with experimental testing data, which were based on a testing procedure recommended by ACI committee 544. Concrete specimens were prepared with two water–cement ratios 0.36 and 0.46. Hooked-end steel fibers with an aspect ratio equal of 80 at 0.5% and 1% volume fractions and polypropylene fibers at 0.2%, 0.3% and 0.5% volume fractions were used. Both the numerical and experimental analysis results indicated that increasing the fiber volume fraction increased the impact resistance of the concrete specimens. The impact resistance increase was greater for normal-strength than that for high-strength concrete. The results also demonstrated that steel fibers are more effective at increasing impact resistance than polypropylene fibers.