Towards modeling of reinforced concrete members with externally bonded fiber-reinforced polymer composites

Fiber-reinforced polymer (FRP) composites have been increasingly studied for their application in the flexural or shear strengthening of reinforced concrete (RC) members. Although substantial increases in strength have been achieved, reductions in ductility have also been reported as a result of debonding failures near the concrete-FRP interface. The debonding phenomenon is the subject of the experimental program described herein, which involved the strengthening of shear-critical beams using carbon FRP (CFRP) strips. It has been determined that the bond-slip behavior at the bond interface must be considered in the numerical modeling of externally reinforced members. Essential to analyses using a finite element program are the formulations of bond elements and their constitutive relations. The implementation of link and contact elements, along with linear elastic and elastic-plastic bond laws, is shown to produce accurate predictions of member response.