Prof. Gamal Ismail Khaleel :: Publications:

High-strength concrete is considered to be a relatively higher brittle material compared with normal concrete. Diagonal tension cracks in high-strength concrete beams can be expected to have a smooth surface, likely to be deficient in aggregate interlock and hence in transmitting shear stresses. Adding steel fiber may improve the shear strength of high-strength reinforced concrete beams. To study this, twelve high strength reinforced concrete beams with and without round steel fiber have been tested. The main variable were, the shear span to depth ratio (aid), and the longitudinal reinforcement ratio (p). The concrete compressive strength was 740 Kg/cm2 for beams with fiber and 710 kg/ cm2 for beams without fiber. The steel fiber content was 1.5% by concrete volume. All beams had the same web reinforcement. An empirical equation is proposed to predict the shear strength of the tested beams. The shear strength of the tested beams were compared with the shear strength calculated by a previous equations in the literature. Adding steel fiber to high-strength reinforced concrete beams increased the shear strength and the stiffness of these beams. KEYWORDS : High strength — concrete — fiber — beams — shear — reinforcement