Shear Capacity of Concrete Beams with FRP Reinforcement

Abstract

This paper presents an experimental and theoretical study on shear performance of concrete I-beams with fiber reinforced polymers (FRP) as internal reinforcement. A total of 24 beam tests were conducted, including tests without shear reinforcement and tests with glass fiber reinforced polymers (GFRP) stirrups and headed bars. In all specimens, GFRP bars were used as flexural reinforcement. The test variables were the ratio of shear reinforcement and the concrete strength. In the tests without stirrups, diagonal tension failure occurred. Failure due to rupture of the GFRP stirrups and headed bars was observed in the tests with lower shear reinforcement ratio of 0.75%. In the beam tests with higher ratio of 1.26% and 2.26%, respectively, depending on the concrete strength, either GFRP shear reinforcement rupture or web crushing failure occurred. Based on the results, a modified approach for calculating the shear capacity of concrete beams with FRP reinforcement was developed.