The effect of steel fiber as addition reinforcement In reinforced concrete beam

Abstract

Steel fiber reinforced concrete has been increasingly used in structural applications during the last four decades. It is generally accepted that addition of steel fibers significantly increases tensile toughness and ductility, also slightly enhances the flexural strength. Effects of steel fibers as addition reinforcement in reinforced concrete (RC) beams are the main objectives of this study. The hooked-end steel fibers with the dimensions of 0.75 mm in diameter, 33 mm in length and with the aspect ratio of 44 were used in this study. Initially the optimum percentage addition of steel fibers in concrete was determined. In order to accomplish this research, eighteen concrete beams with the same mix proportioning of concrete and different volume fractions of steel fiber (0.5 % and 0.75%) were prepared. Then, by determining the flexural strength and deflection of samples, it was concluded that the optimum volume fraction was 0.50 % (0.44 kg). In the next step,the flexural behavior and deflection of RC beams with the addition of steel fibers in concrete was considered. The study was conducted on two types of beam which is beam with 5 links and no steel fibers as a contol beam and the other one was beam with 4 links and 0.50% and 0.75% volume of steel fibers. The overall dimensions of the beams were 150 mm in height, 150 mm in width, and 500 mm in length. The beams were tested under four-point loading test. The results showed that addition of steel fibers in concrete increases the crackingload, load, stiffness and ductility of the concrete beams. Furthermore, the addition of steel fibers has more effect on the properties of RC beams.