Performance of GFRP-Reinforced Concrete Corbels under Monotonic Loading

Reinforced concrete (RC) corbels are commonly utilized in bridges and industrial buildings to support primary beams and girders. Using glass fiber-reinforced polymer (GFRP) reinforcement in corbels can be advantageous due to its corrosion-resistance properties. However, GFRP reinforcement, with a lower modulus of elasticity and shear strength than steel, could affect the capacity of direct shear. This paper presents the experimental results of nine full-scale, double-sided corbels reinforced with either GFRP or steel bent bars. Large-scale double-sided corbels were constructed and tested for failure under monotonic concentric loads. The test parameters included the reinforcement type (GFRP and steel), the main reinforcement ratio (0.5% and 0.7%), the shear span-to-depth ratio (a/d = 0.33 and 0.66), and the amount of crack-control horizontal reinforcement (0.7% and 1.3%). The predictions of corbel capacity using the Canadian standards for FRP-RC structures were conservative, especially for the corbels with crack-control reinforcement. In contrast, the predictions of the American and European codes overestimated the corbel strength, particularly for the higher a/d ratio of 0.66.