Numerical Investigation on the Seismic Retrofitting of RC Beam–Column Connections Using Flange-Bonded CFRP Composites

Abstract

This paper evaluated the capability of nonlinear finite-element (FE) analysis to estimate the seismic responses of reinforced concrete (RC) beam–column connections retrofitted using externally bonded carbon fiber–reinforced polymer (CFRP). As the case studies, a series of the seismically detailed scaled-down (1/2.85) specimens tested previously under either monotonic or cyclic loading were selected and nonlinear FE models were developed to regenerate the experimental results. In order to mimic the practical application in the experimental program the CFRP composites were applied on the top and bottom (flange) sides of the beam with the aim of increasing the flexural strength. The nonlinear FE analyses were performed to consider material and geometric nonlinearity whereas the material properties were obtained from the standard experimental tests on the concrete and steel reinforcements. The accuracy of the numerical results was evaluated by comparing results with those obtained from the experimental tests in terms of the load-displacement curve and failure mechanism. A good agreement was observed between the numerical and experimental results, particularly in estimating the ultimate strength and plastic hinge location of control and retrofitted specimens. Results indicated the reliability of the suggested nonlinear FE analysis as a cost-effective tool for parametric studies of RC beam–column connections retrofitted using flange-bonded CFRP.