Flexural Behavior of Damaged Hollow RC Box Girders Repaired with Prestressed CFRP

Abstract

In recent years, numerous studies have explored the benefits of utilizing prestressed carbon fiber-reinforced polymer (CFRP) for strengthening concrete structures. However, research on the reinforcement of prestressed CFRP on full-scale hollow RC box girders, particularly damaged bridges, remains limited. In this study, both experiments and finite element analysis (FEA) were performed to investigate the flexural behavior of full-scale hollow RC box girders with varying degrees of damage, which were strengthened using CFRP with different levels of prestress. The adhesive behavior of the CFRP–concrete interface was considered in the FEA. Numerical simulations were conducted to assess the flexural behaviors of the girders, including failure modes, yield and ultimate loads, and deflections. The results revealed that the application of prestressed CFRP efficiently increased the yield and ultimate loads of the box girders. Specifically, when the degree of damage of the hollow box girder was less than 23%, the flexural bearing capacity of the repaired girder could be recovered after being strengthened with two prestressed CFRP strips measuring 50 mm in width and 3 mm in thickness. However, the risk of premature debonding at the CFRP–concrete interface increased when the prestressing level of CFRP and degree of damage of hollow RC box girders exceeded 35% and 40%, respectively. These findings suggest that the use of prestressed CFRP may be a promising method for repairing damaged hollow RC box girders, but careful consideration of the degree of damage and prestressing level would be necessary to ensure the effectiveness and safety of the repair.

Carbon Fibre-Reinforced Polymer (CFRP) Composites in Civil Engineering Application—A Comprehensive Review

“…A coded trapezoidal mixed-mode cohesive zone model (CZM) in the user subroutine ABAQUS of UMAT was used to design the failure of ductile adhesive in the strengthened beam using CFRP, and this method is found to be more efficient because of its increased stress distribution, fracture energy, and reduced stress. Guo et al (2023) discussed the behaviour of load deflection, ultimate debonding, and load capacity by absorbing the 14 beams that contain 1 notched beam, 1 intact beam, and 12 CFRP retrofitted beams under varying temperatures of about 20 °C to 80 °C [43]. Bond slip behaviour was observed for different CFRP strain measurements, and the debonding load varies based on temperature change; that is, it decreased at 80 °C and increased for the temperature from 20 °C to 60 °C, and the energy of interfacial fracture reduced with the improvement of temperature.…”

“…The experimental result shows that the CFRP bars used in the column subjected to the elevated temperature show increased compressive resistance of 3 to 15% at a lower temperature of 150 • C, 7 to 13.6% at an increased temperature of 300 • C, and 50% at 450 • C [16]. Guo et al (2023) conducted a study in which full-scale hollow RC box girders with different degrees of damage strengthened using CFRP with prestress of various levels were investigated regarding flexural behaviour. The study involved experiments and finite element analysis (FEA) [17].…”

“…Guo et al (2023) conducted a study in which full-scale hollow RC box girders with different degrees of damage strengthened using CFRP with prestress of various levels were investigated regarding flexural behaviour. The study involved experiments and finite element analysis (FEA) [17]. Numerical simulations evaluated the flexural behaviour of the girders, including modes of failure, yield and maximum capacities, and deflections.…”

“…The result indicates the proposed failure mode calculation to help decide the bending failure and bending capacity of the RC beams with sheets of CFRP.Wang et al (2023) analysed the strengthening behaviour of CFRP-strengthened steel beams by adopting a three-dimensional finite model to encourage the mechanical response under a static four-point bending load[42]. A coded trapezoidal mixed-mode cohesive zone model (CZM) in the user subroutine ABAQUS of UMAT was used to design the failure of ductile adhesive in the strengthened beam using CFRP, and this method is found to be more efficient because of its increased stress distribution, fracture energy, and reduced stress Guo et al (2023). discussed the behaviour of load deflection, ultimate debonding, and load capacity by absorbing the 14 beams that contain 1 notched beam, 1 intact beam, and 12 CFRP retrofitted beams under varying temperatures of about 20 • C to 80 • C[43].…”

Experiments on shear behavior of reinforced concrete continuous beams strengthened by C‐FRCM

“…[2][3][4][5][6][7][8] A typical FRP material used for retrofitting is carbon fiber-reinforced polymer (CFRP). Some existing experimental studies [9][10][11][12][13] have indicated that CFRP offered great performance in the improvement of the mechanical behavior of RC structures.…”