Innovative flexural strengthening of RC beams using self-anchored prestressed CFRP plates: Experimental and numerical investigations

• Published in: Engineering structures Vol. 243; p. 112687
• Main Authors: Yang, Jincheng, Johansson, Morgan, Al-Emrani, Mohammad, Haghani, Reza
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15-09-2021; Elsevier BV
• Subjects: Anchorages; Bearing strength; Bonding strength; Carbon fiber reinforced plastics; Carbon fibre reinforced polymer (CFRP); Carrying capacity; Debonding; Fiber reinforced polymers; Finite element method; Flexural strengthening; Intermediate crack-induced debonding; Investigations; Load carrying capacity; Mechanical properties; Model testing; Nonlinear finite element analysis; Plates; Polymers; Prestress; Prestressing; Reinforced concrete; Reinforced concrete (RC); Self-anchorage; Stiffness; Strengthening; Flexural strengthening; Nonlinear finite element analysis; Carbon fibre reinforced polymer (CFRP); Prestress; Intermediate crack-induced debonding; Self-anchorage; Reinforced concrete (RC)
• ISSN: 0141-0296; 1873-7323; 1873-7323
• DOI: 10.1016/j.engstruct.2021.112687

•Self-anchored prestressed CFRP plates without the need for mechanical end anchorage.•Significant improvement in bending stiffness, crack width, and load-carrying capacity.•Nonlinear finite element analyses of flexural cracks and crack-induced debonding of CFRP plates.
This paper presents an innovative method of prestressing carbon fibre reinforced polymer (CFRP) plates used as externally bonded reinforcement for flexural strengthening of reinforced concrete (RC) beams. The proposed method aims to achieve self-anchorage of the prestressed CFRP plate and thus eliminate the need for conventional mechanical anchorage at its ends. Experimental tests of RC beams in four-point bending were conducted to investigate the strengthening efficiency of the self-anchored prestressed CFRP plate. The experimental results showed that using the self-anchored prestressed CFRP significantly improved the flexural performance of the strengthened beam in terms of bending stiffness, crack widths, and load-carrying capacity. The utilisation ratio of the prestressed CFRP plate reached 81% at its debonding. Numerical analyses using nonlinear finite element (FE) method were conducted to model the tested specimens. Based on the reliable simulation of flexural cracks and crack-induced CFRP debonding, parametric studies were conducted using FE analyses, in order to investigate the effect of prestressing levels and the CFRP plate’s stiffness on the flexural behaviour. Recommendations were then made for selecting a proper prestressing level and the mechanical properties of CFRP plates.