In this research an attempt was made to investigate the behavior and the ultimate shear strength of hooked end steel fiber reinforced concrete beams without traditional shear reinforcement. The addition of steel fibers in a plain concrete mix helps to bridge and restrict the cracks formed in the brittle concrete under applied loads, and enhances the ductility of the concrete. The shear failure in a concrete beam is a brittle type of failure. Canadian code provisions correlates well with the experimental results taking in to account the size effect. The accuracy of the Zsutty's equation is relatively better than ACI approaches and but it does not take in to account the size effect. The Bazant's method is underestimating the ultimate strength. ACI code and Okumaro's equation can predict the shear strength trend reasonably well for slender beams. Test results were compared with the strengths predicted by ACI code, CEB-FIP Model, Zsutty's equation, Okumaro's equation and also with Bazant's method. This study investigated the influence of beam depth with varying longitudinal reinforcement and minimum shear reinforcement. Test variables were shear reinforcement percentage (ρ v varying from 0.2682 to 0.3351), longitudinal steel percentage (ρ l varying from 2.78 to 3.43) and effective depth (varying from 400 to 500 mm) with constant compressive strength (f ck =70 MPa) and shear span to effective depth (a v /d) =2.6. Nine high strength reinforced concrete beams with minimum shear reinforcement and heavier than minimum as per ACI code, were tested to investigate their size effects on shear strength for medium depth beams (d ranges from 305 to 560 mm), ultimate shear capacity and failure modes.
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