FRP/stirrups interaction of shear-strengthened beams

Abstract

This work includes experimental testing and finite element analysis of fiber reinforced polymer (FRP) shear-strengthened reinforced concrete (RC) beams. The strengthening techniques used for the beam strengthening are namely; mechanically fastened, bonded, and hybrid mechanically fastened/bonded-FRP techniques. The experimental part of this study is also devoted to investigating the possible interaction between the FRP plates and the transverse steel reinforcement (stirrups) located along the critical shear span where the strengthening took place. The objective of the numerical component of this research is to numerically, using the finite element method, assess the shear behavior of beams strengthened using any of the three techniques above. The interfacial slip between the hybrid strengthening FRP and the concrete is taken into consideration, here, using specially developed interface elements. Results of the experimental and numerical modeling are presented regarding the effect of the FRP/stirrups interaction on the maximum load. Also, the interfacial slip distributions are discussed. The findings of the finite element modeling are substantiated based on comparisons with the experimental results and show adequate conformity.