Experimental and Statistical Analysis of Repeated Impact Records of Hybrid Fiber-Reinforced High-Performance Concrete

The effect of fiber type and hybridization on the repeated impact strength was investigated experimentally using six high-performance concrete mixtures reinforced with a 2.5% volume fraction. types considered in this study included short steel fibers (SF) 6 mm length, long SF 15 polypropylene (PP) fibers. test conducted specially made automatic testing machine following setup recommendations ACI 544-2R test, where cracking (Ncr) failure (Nf) numbers were recorded mode crack pattern observed. results statistically analyzed normality variations discussed. showed that specimens pure (S15) obtained highest Ncr Nf values, which 20% 327% higher than those mixture (S6) owing to better bond between cementitious matrix S15. Replacing 0.5% mixture’s PP decreased resistance by 7% 15%, while its dependent length SF. In most cases, records did not exhibit significant departure from normal distribution, according Anderson-darling test.