Experimental Research On Shear Capacity Of RC Beams Strengthened With Externally Bonded Carbon Fiber Reinforced Polymer Sheets

As a new structural engineering material, carbon fiber reinforced polymer (CFRP) has many advantages in concrete structures strengthened. However, the theoretical research on shear behavior of RC beams strengthened with externally bonded CFRP sheets is imperfect.In this paper, based on the experiment of twenty one simply supported RC beams strengthened with externally bonded CFRP sheets, the ultimate shear capacity, the load-deflection relationship of beams, the failure pattern and the influence factors of shear capacity such as CFRP layer, shear ratio and strengthened method are researched and analyzed. Based on the analysis of the experiment results, the working mechanism of CFRP that is used to strengthen the shear capacity of RC beams is studied.In this paper, based on the research of the data of experiment, a truss-arch model is set up. Based on that, the author sets up the shear capacity mechanical model of RC beams strengthened with CFRP. As a result, this paper brings forward design formula to calculate the shear strength of RC beams that are strengthened with externally bonded CFRP. By comparison with the experimental data, the formula tallies well.At the same time, a finite element method models are developed to simulate the behavior of RC beams strengthened with externally bonded CFRP. In this study, to reduce the error caused by ignoring the slippage of glue in previous research, an element named COMBIN39 is used to simulate the slippage. It compares the loads at failure, strains of stirrups and strains of CFRP from the FEM analysis results and the experiment data. Conclusions from the current research efforts and recommendations for future studies are included.