29 Jul Doctoral thesis on Carbon Fiber-Reinforced Polymers for strengthening Reinforced Concrete structures
On July 16, 2024, Alba Codina defended her PhD thesis titled “Study of debonding in CFRP-strengthened RC beams and contribution of anchorage systems” at the University of Girona. Her research was supervised by Dr. Cristina Barris and Dr. Lluís Torres (AMADE – Universitat de Girona).
Her research focuses on the rehabilitation of buildings and infrastructure, specifically the use of Carbon Fiber-Reinforced Polymers (CFRP) for strengthening Reinforced Concrete (RC) structures. The study aims to address the challenge of premature debonding of CFRP from the concrete surface, which limits the effective use of CFRP’s mechanical properties. It investigates Intermediate Crack Debonding (ICD) in externally bonded (EB)-FRP strengthened RC beams to understand the mechanisms causing this failure mode both theoretically and experimentally. Additionally, the research evaluates anchorage techniques such as Externally Bonded Reinforcement on Grooves (EBROG) and Hybrid Bonding (HB)-FRP to mitigate premature debonding.
Alba Codina’s PhD research contributes to the inclusion of a comprehensive study of ICD in EB-FRP strengthened RC beams using precured laminates, both theoretically and experimentally. She conducted a detailed comparison of theoretical predictions with experimental results from four-point bending tests on RC beams with varying concrete strengths and internal steel reinforcement ratios. This study assessed the effectiveness of different prediction models from the literature using an extensive experimental database. Additionally, she investigated the performance of anchorage techniques such as EBROG and HB-FRP through bond and flexural tests, revealing their effectiveness in improving bond and flexural performance, delaying ICD in RC beams strengthened using CFRP precured laminates. To further study ICD, she developed a numerical model that simulates ICD for several bond-slip laws applicable to different strengthening techniques, accurately predicting ICD failure by limiting excessive tensile forces between cracks. This model was validated against experimental data, demonstrating its accuracy for EB, EBROG, and HB-CFRP specimens and highlighting its applicability across different strengthening methods.
This research was funded by the Spanish Ministry of Science, Innovation and Universities, project PID2020-119015GB-C22. The period of research has been funded by the Generalitat de Catalunya, under the Grant number 2020_FISDU 00476.
