PSI - Issue 64

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 64 (2024) 1557–1564

SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Analytical study of FRP debonding in a real-scale concrete strengthened beam Francesco Focacci a *, Tommaso D'Antino b , Christian Carloni c a University eCampus, Via Isinbardi 10, Novedrate (CO) 22060, Italy b Politecnico di Milano, Department of Architecture, Built Environment and Construction Engineering, Piazza Leonardo da Vinci 32, Milan 20133, Italy. c Case Western Reserve University, Departement of Civil and Environmental Engineering, 10900 Euclid Ave., Cleveland (OH) 44106, USA. Abstract The exploitation of the mechanical properties of fiber-reinforced polymers (FRP) externally bonded to concrete members is limited by the occurrence of debonding. Single- and double-lap shear tests were performed to study the debonding process. However, the results of these tests fail to describe the debonding process when multiple substrate cracks occur, as in the case of reinforced concrete beams strengthened in flexure. In this paper, an analytical model is proposed to describe the load response of a concrete beam strengthened in flexure with an externally bonded FRP composite. The profiles of the FRP-concrete slip, FRP axial force, and cross-section rotation, the evolution of the cracking process, and the failure mode may be obtained by this model. The results of the model shed light on the debonding process in FRP-strengthened beams and may be used to investigate the relationship between the bond capacity of FRP-concrete interfaces with a single crack and that observed in real-scale strengthened beams. © 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 Keywords: FRP; debonding; analytical model; concrete beam.

1. Introduction Fiber-reinforced polymer (FRP) composites are used as externally bonded (EB) reinforcement of concrete and reinforced concrete (RC) members. They can be used to improve the beam bending and shear strength (Chen and Teng

* Corresponding author. E-mail address: francesco.focacci@uniecampus.it

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.2024.09.409