Numerical Assessment of the Effect of CFRP Anchorages on the Flexural and Shear Strengthening Performance of RC Beams

This study investigates the effectiveness of a hybrid solution that combines carbon fiber-reinforced polymer (CFRP) systems for the flexural and shear strengthening of T-cross section reinforced concrete (RC) beams. The hybrid solution consists of near-surface mounted CFRP laminates for flexural enhancement and externally bonded U-shaped CFRP strips for shear strengthening. Moreover, an innovative CFRP anchorage system is proposed to prevent premature debonding of the U-CFRP strips and to improve their shear contribution. To address the limitations of the experimental program and propose an efficient and design-oriented simulation approach for NSM-EBR strengthening RC beams with the innovative anchorage system, a comprehensive numerical investigation was conducted by considering the key parameters affecting the performance of the strengthened system. This paper presents the results of an experimental program and a nonlinear finite element analysis that simulate the behavior of the materials up to their failure and the bond conditions between CFRP and concrete. This study also includes a numerical parametric study to assess the effectiveness of the proposed strengthening concept with several possible scenarios, as well as the predictive performance of the fib Bulletin 90 and ACI 440.2R-17 formulations.