SHEAR PERFORMANCE OF CONCRETE BEAMS OF LOW SHEAR SPANS REINFORCED WITH HIGH-STRENGTH STEEL SURAJ KU

This paper presents an experimental investigation on the shear behavior of concrete beams of low shear span-to-depth ratios with the high-strength reinforcing steel. Six beam specimens with two different grades of steel (500 and 550 MPa) as the longitudinal reinforcement and three different grades of steel (500, 550, and 600 MPa) as the transverse reinforcement were tested under monotonic loading conditions. Two different concrete grades were considered in the test specimens, whereas the shear span-to-depth (a/d) ratios were varied in the range of 1.05-1.70. The spacing of stirrups in the beam specimens was proportionately varied based on their specified yield strengths for a constant percentage of longitudinal steel. Test results showed that beams with low concrete compressive strength and reinforced with 500 MPa grade longitudinal steel exhibited the diagonal shear failure, whereas the beams with high concrete compressive strength and reinforced with 550 MPa grade longitudinal steel failed in the predominantly flexure mode. In addition to the yielding of longitudinal reinforcement bars, the yielding of stirrups was observed in all beams including the specimen having a higher a/d ratio. It was concluded that the yield strength of transverse steel reinforcement in the concrete beams could be increased to 600 MPa without exceeding the safety and serviceability criteria. © 2022, Associated Cement Companies Ltd.. All rights reserved.