Investigation and comparison of the influence of steel, polypropylene, and korta fibers in improving the flexural performance of reinforced concrete beams

The advantages of reinforced concrete structures , in comparison with other structures, have made concrete one of the most widely used construction materials. However, concrete has brittle performance under flexural loads. Therefore, the present study investigates the influence of different fibers on the flexural performance of large-scale reinforced concrete beams. In order to achieve this goal, four reinforced concrete beams, with similar reinforcement details, measuring 150 cm long, 20 cm wide, and 30 cm high were made. The beams were reinforced using 0.5% by volume of steel, polypropylene, and korta fibers. Based on ASTM C78, four-point flexural test was performed and the parameters of flexural strength, energy absorption, ductility, and strain of the rebars were studied. The results indicated that reinforced concrete beam containing steel fibers shows better performance, in terms of flexural strength, energy absorption, and capacity of tensile rebars, in comparison with reinforced concrete beams containing polypropylene and korta fibers. In addition, this study showed that korta fiber reinforced beam has better ductility than polypropylene fiber reinforced beam.