Description
In the last two decades, fiber-reinforced polymer (FRP) composites have become a popular solution for flexural strengthening of existing reinforced concrete (RC) members. Their success is partly due to the extensive research performed to deeply understand the behavior of FRP-strengthened RC members, which resulted in the publication of various design codes and guidelines all over the world. Most of the design formulations employed to estimate the bending capacity of FRP-strengthened RC beams are based on a fracture mechanics approach that limits the composite axial stress due to the occurrence of composite debonding from the substrate. Different model parameters are provided by design codes and guidelines to account for the differences between intermediated crack-induced (IC) debonding and plate end (PE) debonding. Among available guidelines, the fib Bulletin 90 provides numerous approaches that promisingly allow for an accurate estimation of the FRP-strengthened RC beam bending strength.
In this paper, the accuracy of formulations provided by the fib Bulletin 90 to estimate the bending capacity of FRP-strengthened RC beams is assessed. A database comprising results of experimental bending tests of FRP-strengthened RC beams is collected. Comparison between experimental and corresponding analytical results obtained with fib Bulletin 90 bending strength models allows to identify accuracy, differences, and peculiarities of each approach considered.
