Hybridization of polypropylene–steel fiber leads to improvements of both the mechanical properties and impact resistance of concrete. This paper provides the results of an experimental impact test, which has been conducted using a low-velocity drop hammer (with an impact velocity of 2.8 m/s) on fiber-reinforced concrete (FRC) and fiber-reinforced rubberized concrete (FRRuC) prisms. Prism specimens, measuring 100 × 100 × 500 mm (depth × width × length), were prepared. The variables were different ratios of micro steel (MS) fiber (0%, 0.75, 0.825, 0.9%, 1.0%) and polypropylene (PP) fiber (0%, 0.1%, 0.175, 0.25%, 1%) with/without crumb rubber (CR) with a partial replacement of fine aggregate at a ratio of 20% by volume. FRC with CR produced higher first and final impact energy compared with prisms without CR. By contrast, the density, as well as the compressive and tensile strengths decreased, whereas the voids and water absorption of concrete increased due to the CR replacement. The specimen, which was reinforced with 0.9% MS + 0.1% PP hybrid FRRuC, produced high final impact energy of approximately 887.2 J, which was 10 times higher than that of plain concrete ; the impact ductility index was 4.15, which was twice the value of plain concrete. Furthermore, the most significant improvement in mechanical properties was found for specimens with 0.9% MS + 0.1% PP hybrid fiber.

聚丙烯-钢纤维的杂交可改善混凝土的机械性能和抗冲击性。本文提供了使用低速落锤（冲击速度为2.8 m / s）在纤维增强混凝土（FRC）和纤维增强橡胶化混凝土（FRRuC）上进行的实验冲击测试的结果。棱镜。准备尺寸为100×100×500 mm（深度×宽度×长度）的棱镜样品。变量是有/无微钢（MS）纤维（0％，0.75、0.825、0.9％，1.0％）和聚丙烯（PP）纤维（0％，0.1％，0.175、0.25％，1％）的不同比率碎橡胶（CR），其中细骨料的部分替代比例为20体积％。与不带CR的棱镜相比，带CR的FRC产生更高的第一和最终冲击能量。相比之下，密度 以及抗压强度和抗拉强度降低，而混凝土的空隙和吸水率由于CR的替代而增加。用0.9％MS + 0.1％PP混合FRRuC增强的试样产生了约887.2 J的高最终冲击能，是普通混凝土的10倍。冲击韧性指数为4.15，是普通混凝土的两倍。此外，发现具有0.9％MS + 0.1％PP杂化纤维的样品的机械性能有了最显着的改善。是普通混凝土的10倍; 冲击韧性指数为4.15，是普通混凝土的两倍。此外，发现具有0.9％MS + 0.1％PP杂化纤维的样品的机械性能有了最显着的改善。是普通混凝土的10倍; 冲击韧性指数为4.15，是普通混凝土的两倍。此外，发现具有0.9％MS + 0.1％PP杂化纤维的样品的机械性能有了最显着的改善。