FLEXURAL BEHAVIOR OF STEEL FIBER REINFORCED HIGH-STRENGTH CONCRETE BEAMS WITH HRB600 STEEL BARS UNDER MONOTONIC LOADING

The flexural behavior of 4 steel fiber reinforced high-strength concrete beams with HRB600 steel bars was tested with different steel fiber contents and concrete strength grades. At the same time, the failure characteristics, deflection, bearing capacity, longitudinal reinforcement strain and crack width were compared and analyzed, and the calculation methods of ultimate bearing capacity, deflection and crack width were evaluated. The test results showed that the section strain change of steel fiber reinforced concrete beam with HRB600 steel bars conformed to flat section assumption. Steel fiber could effectively improve the bending cracking load and deformability of high-strength concrete beams and limit the generation and development of the bending vertical cracks. With the increase of steel fiber content, the flexural bearing capacity of steel fiber reinforced high-strength concrete beams increased. The current calculation method of CECS 38∶2004 Technical Specification for Fiber Reinforced Concrete Structures was still applicable to the calculation of the ultimate bearing capacity, maximum crack width and deflection of the steel fiber reinforced high-strength concrete beams with HRB600 steel bars.