Analytical model for predicting the shear strength of FRP-retrotted exterior reinforced concrete beam-column joints

In this study, a nonlinear procedure for analysis of a membrane element ofa frp strengthened concrete beam-column joint is proposed, based on a softened trussmodel. the procedure employs three equations for equilibrium, three for compatibility,and six for the constitutive laws of materials. the model is capable of analysing thenonlinear behaviour of rc beam-column joints under cyclic loading, and has three majorattributes: nonlinear association of stress and strain in the presence of frp, contributionof concrete damage by means of a softening coecient, and consideration of the bond eectbetween steel, frp and concrete. the proposed model is applied to some previously testedand strengthened beam-column joints, and shows good predictions of their shear strength.the eect of various parameters on the response of a reinforced concrete beam-columnjoint, such as a column axial load, amount of frp reinforcement, and frp properties, hasbeen studied in a parametric manner. it is observed that even a low quantity of frp canenhance the shear capacity of the joint signicantly. also, it is observed that the axial loadincreases the connement of the joint care, which, in turn, increases the shear capacity ofthe joint.