Research on optimal design of mechanical properties of hybrid fiber-reinforced concrete

In this study, the influence of the dosage optimization of steel fibers (SFs), basalt fibers (BFs), and polypropylene fibers (PPFs) on the mechanical properties of hybrid fiber-reinforced concrete (HFRC) is investigated, including cube compressive strength, splitting tensile strength, and prism compressive strength. The orthogonal method was used to design the fiber mixtures to optimize the performance of the specimens. IBM SPSS Statistics software was used to analyze the significance sequence of the influencing factors of SFs, BFs, and PPFs through range and variance. The influence degree and significant affecting factors of the three fiber types were obtained, and the failure states of the HFRC specimens were analyzed. Finally, a strength prediction model for HFRC was established based on the test results. The results show that for the degree of influence on the strength of HFRC, the degree of influence of SFs was greater compared to BFs, and the degree of influence of PPFs was the smallest. In addition, for the factors that affect the strength of HFRC, the content of SFs was the primary factor, the fiber content of BFs was less important, and the content was not an important factor for PPFs. The strength prediction model established based on the orthogonal test data can well reflect the influence of three fibers types and contents on the strength of HFRC. In order to verify the validity of the present model, experimental results reported in the literature were compared with the values calculated with the present model.