Flexural Performance of Beams Strengthened with FRP Laminates and Alternative U-Wrap Anchors

Fiber Reinforced Polymer (FRP) Premature Debonding Alternative U-Jackets Finite Element Study Abaqus.

Authors

  • Sneha M. Varghese
    Sneha.Marium@dxb.manipal.edu
    Department of Civil Engineering, Manipal Academy of Higher Education, Dubai Academic City, Dubai, 345050,, United Arab Emirates http://orcid.org/0000-0002-3863-8523
  • Kiran Kamath Department of Civil Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104,, India
  • Rajiv Selvam Department of Mechanical Engineering, Manipal Academy of Higher Education, Dubai Academic City, Dubai, 345050,, United Arab Emirates
  • Surumi Rasia Salim Department of Civil Engineering, University of Calgary, Calgary, T2N 1N4,, Canada

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Premature debonding is identified as the main failure mode in reinforced concrete (RC) beams strengthened with externally bonded Fiber-Reinforced Polymer (FRP) laminates. This issue leads to the underutilization of FRP materials and needs to be addressed. Research has shown that end anchorage systems can effectively delay/mitigate delamination failures and enhance the performance of strengthened beams. FRP U-wraps are an effective means to prevent debonding failure; however, as open-form anchors, U-wraps cannot always guarantee complete resistance to debonding failures. This study proposes an alternative U-wrapping technique where the ends of the U-wraps are flared and inserted into the concrete substrate. The feasibility and effectiveness of this technique were studied by comparing it with conventional U-wraps. The experimental phase involved testing seven RC beams, each measuring 1.96í—0.15í—0.3 meters, under four-point bending. The results showed that the anchorage technique improved beam performance in terms of load-deflection behavior, failure modes, ductility, and FRP strain. Additionally, finite element simulations were conducted using Abaqus software to assess the effectiveness of the alternative U-wrap scheme. These models incorporated various nonlinear material constitutive laws, including cohesive zone modeling to replicate debonding failures at the CFRP-concrete interface. The numerical predictions were found to be in good agreement with the experimental test data.

 

Doi: 10.28991/CEJ-2024-010-08-01

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