PSI - Issue 64

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2024) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 64 (2024) 1540–1548

SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Complementary Use of CFRP U-Wraps as Supplemental Shear Reinforcement and Anchorage in Reinforced Concrete Beams Strengthened with Flexural Externally Bonded CFRP Sheets Muhammad Ishfaq a , Ravi Kanitkar b , Kent A. Harries c , Jovan Tatar d, * a PhD Student, Department of Civil and Environmental Engineering, University of Delaware, P.O. Box 19716, Delaware, USA b Principal KL Structures, Austin, Texas, USA c Professor, Department of Civil & Environmental Engineering, University of Pittsburgh, Pittsburgh, P.O. Box 15260 PA, USA d Associate Professor, Department of Civil and Environmental Engineering, University of Delaware, P.O. Box 19716, Delaware, USA Abstract This research explores complementary shear strengthening and anchorage effects of CFRP U-wraps on reinforced concrete beams strengthened in flexure using externally bonded CFRP sheets. Through experimental testing of large-scale beams, the research aims to enhance the understanding of how the dual strengthening and anchorage functions of U-wraps interact and contribute to the overall structural performance of flexurally-strengthened beams. The specimens were divided into three groups based on existing steel shear reinforcement ratio; each was strengthened with different configurations of U-wraps and fiber anchors. This paper reports the results of twelve beams tested to date. The test matrix is designed in a way that evaluates the conditions under which shear-controlled beams transition to flexure-controlled failure modes, allowing for the evaluation of the dual contribution (i.e., shear strengthening and anchorage) of U-wraps. Based on the initial results, U-wraps increased shear strength by 76% in shear deficient beams while, at the same time, increasing the strain utilization of flexural CFRP sheets in flexure-controlled specimens by up to 118% over the ACI 440.2-prescribed debonding strain. The addition of U-wraps also shifted the failure mode of flexural CFRP sheet from intermediate crack (IC) debonding to U-wrap rupture or U-wrap debonding. © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers

* Corresponding author. Tel.: +1 302-831-4939. E-mail address: jtatar@udel.edu

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers 10.1016/j.prostr.2024.09.407