Investigation of flexural behavior of the steel fiber reinforced concrete hollow section beams

The flexural behavior of the steel fiber reinforced concrete hollow beams under two-point load is discussed in this study. The ultimate load capacity and deformation of hollow beams were investigated experimentally and compared with the solid beams) which have the same properties of the concrete mixture. All the beams that were tested in this study were square beams with a section width of 150 mm, section depth of 150 mm and the beam length of 850 mm (the span of 750 mm). All beams were simply supported tested under two points load. Twelve concrete beams including four solid sections, while the rest eight beams are hollow with a square cavity. The effect of opening size, steel fiber content and longitudinal steel reinforcement are investigated to evaluate the response of beams to carry the applied load. The current experimental results approve that the usage of steel fiber in concrete mixture did not noticeably affect the compressive strength while significant increase in splitting tensile strength and led to better flexural behavior and increased the ultimate load capacity, on the other hand, the hollow beams resulted in lower ultimate load, which was decreased as the opening size increase