Behavior of Reinforced Concrete Beams Strengthened By GFRP Composites Subjected to Combined Bending and Torsion – Experimental Study

Abstract

This paper presents an experimental investigation on the behavior of reinforced concrete beams subjected to combined bending and torsion, strengthened by using externally bonded glass fiber reinforced polymer (GFRP). The experimental work includes an investigation of three RC beams tested under combined bending and torsion. One beam is kept without strengthening as a control specimen, while the other two beams are strengthened using GFRP wrapping with different configurations. All RC beams have the same concrete grade and steel reinforcement. The strengthened beams in the experimental study include full wrapping with continuous GFRP sheets and discrete GFRP strips with the same GFRP reinforcement ratio. The load-mid span deflection curves and the torsional moment-twist angle curves were recorded to failure. The crack patterns and failure modes of the RC beams were also indicated. The Experimental results reveal that strengthening by using GFRP wrapping helped effectively in improving the overall performance of the strengthened beams.