Shear Performance of RC Beams Strengthened with High-Performance Fibre-Reinforced Concrete (HPFRC) Under Static and Fatigue Loading

Liu, Xiangsheng; Thermou, Georgia E.

Abstract

This study experimentally assessed the shear performance of reinforced concrete (RC) beams strengthened with U-shaped High-Performance Fibre-Reinforced Concrete (HPFRC) under static and fatigue loading. Key parameters included HPFRC jacket thickness and beam shear span–depth (a/d) ratio. Five beams were tested under static loads to determine ultimate shear strengths, followed by fatigue tests on identical beams at 30–70% of ultimate shear strengths at 4 Hz. In static loading experiments, all the HPFRC jacketing proved effective, increasing the shear strength of RC beams by 95% to 130%. Although the strengthening system did not change the failure mode of the beams, the strengthened beams exhibited pseudo-ductile behaviour. As the a/d increased, the shear enhancement capability of the HPFRC jackets decreased. In fatigue loading experiments, all the HPFRC systems improved the fatigue life of RC beams. Specifically, in beams with an a/d ratio of 2.0, the fatigue life was extended from 75 cycles to a maximum of 951 cycles, while in beams with an a/d ratio of 3.5, it increased from 12,525 cycles to 48,786 cycles. In addition, a predictive model has been developed for the fatigue life of HPFRC/UHPFRC shear-strengthened beams, utilising the maximum fatigue load and the design’s ultimate shear strength under static loading conditions.

Citation

Liu, X., & Thermou, G. E. (2024). Shear Performance of RC Beams Strengthened with High-Performance Fibre-Reinforced Concrete (HPFRC) Under Static and Fatigue Loading. Materials, 17(21), Article 5227. https://doi.org/10.3390/ma17215227

• Journal Article Type: Article
• Acceptance Date: Oct 25, 2024
• Online Publication Date: Oct 27, 2024
• Publication Date: Nov 1, 2024
• Deposit Date: Nov 3, 2024
• Publicly Available Date: Nov 5, 2024
• Journal: Materials
• Electronic ISSN: 1996-1944
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 17
• Issue: 21
• Article Number: 5227
• DOI: https://doi.org/10.3390/ma17215227
• Keywords: reinforced concrete; beam; HPFRC; fibre-reinforced concrete; shear strengthening; retrofitting; fatigue
• Public URL: https://nottingham-repository.worktribe.com/output/41368982
• Publisher URL: https://www.mdpi.com/1996-1944/17/21/5227