Strengthening of RC beam-column joints with composites: Analytical model and experimental verification

Analytical models are presented in this study for the analysis of RC joints strengthened with composite materials. The models provide equations for stresses and strains at various stages of the response (before or after yielding of the beam or column reinforcement) until the ultimate capacity is reached, defined by concrete crushing or FRP failure due to fracture or debonding. Solutions to these equations are obtained numerically. The models provide useful information on the shear capacity of FRP-strengthened joints in terms of the quantity and configuration of the externally bonded reinforcement and may be used to design FRP jackets for poorly detailed beam-column joints. The analytical procedure is illustrated through a case study. Finally, the analytical model is compared with a series of test results and the agreement between theory and experiments is found satisfactory.