Experimental Study of Flexural Performance of Concrete Reinforced Hybrid Fiber made by Combining Polypropylene and Basalt Fiber

Abstract

In this study, the effects of combined high elastic modulus and low elastic modulus fibers mixed to form hybrid fiber and utilize in concrete mixture on the flexural strength were evaluated. A grade 32.5A slag cement was used to cast the specimens, hybrid fiber which involves polypropylene (PPF) and basalt fiber (BF) using three mixing ratios BF: PPF = 1:1, 2:1, and 1:2 added by 0.3 to 1.2% (interval of 0.3%) to prepare the concrete mixture. The concrete beams with dimensions 100 × 100 × 400 mm were cast for a 4 points bending test. The results revealed that the flexural strength of hybrid fiber reinforced concrete samples significantly improved in both three mixing ratios of hybrid fiber. Furthermore, the maximum flexural strength of 4.27 MPa representing an increased strength of 52% compared to plain sample was obtained from the concrete mixture prepared with a mixing ratio of 1:1 hybrid fiber. Minor cracks were the predominant failure mode of the specimen after testing; indicating the ductility of the concrete was improved.