Performance of End-Anchorage Systems for RC Beams Strengthened in Shear with Epoxy-Bonded FRP

Abstract

This paper presents the results of an experimental investigation on the performance of full-scale reinforced concrete (RC) T-girders strengthened in shear using externally bonded (EB) fiber-reinforced polymer (FRP) U-jackets end-anchored with different systems. Debonding of FRP, particularly in shear, is a major failure mode when using FRP sheets to strengthen concrete structures. Design code provisions and guidelines related to shear-strengthening of RC beams using externally bonded FRP (EB FRP) suggest the use of end-anchorage systems to prevent FRP debonding. However, no guidelines are available for the design and effectiveness of end-anchorage systems. The main objective of this study is to evaluate the effectiveness of different end-anchorage systems for RC beams strengthened using EB FRP methods. To this end, nine tests were performed on 4520-mm-long RC T-beams. Four specimens were strengthened in shear using EB FRP methods with various end-anchorage systems, and their performance was compared with similar specimens strengthened with: (1) EB FRP with no anchorage; (2) near-surface-mounted (NSM) FRP rods; and (3) embedded through-section (ETS) FRP rods. The results of this study reveal that specimens retrofitted with EB FRP methods and properly designed end-anchorage systems can achieve a superior contribution to shear resistance compared with specimens strengthened using EB FRP with no anchorage, NSM, or ETS methods.