Effect of FRP U-jackets on the behaviour of RC beams strengthened in flexure with NSM CFRP strips. (15th January 2021)

• Record Type: Journal Article
• Authors: Zhang, S.S.; Ke, Y.; Smith, S.T.; Zhu, H.P.; Wang, Z.L.
• Is Part Of: Composite structures. Volume 256(2021)
• Publication Date: 2021-01-15
• Subjects: Debonding -- Fiber-reinforced polymer (FRP) -- Flexural strengthening -- FRP U-jacket -- Near-surface mounted (NSM) -- Reinforced concrete (RC); Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2020.113095
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: The near-surface mounted (NSM) fibre-reinforced polymer (FRP) strengthening technique has become a viable strengthening method for reinforced concrete (RC) beams. Premature debonding failure of the NSM FRP strips is a common failure mode though that severely limits the effectiveness of the FRP intervention that results in reduced beam strength and deformability. The application of FRP U-jackets near the ends of the NSM strips offers a potential solution to the debonding problem. This paper presents the first systematic experimental investigation on the use of FRP U-jackets for delaying or preventing debonding failure in RC beams strengthened in flexure with tension face NSM FRP strips. A total of 11 large-scale RC beams were tested, with the investigated parameters being (i) arrangement of NSM carbon FRP (CFRP) strips, (ii) U-jacket material type, (iii) layout, width and inclination angle of FRP U-jackets. Failure modes, load-deflection and strain distribution responses of all tested beams were recorded. The test results bring clarity and understanding to the tested parameters and they also demonstrate the effectiveness of the U-jacket intervention.