Structural evaluation of reinforced concrete beams strengthened with innovative bolted/bonded advanced frp composites sandwich panels

This paper presents and evaluate the performance of a novel, non-conventional fiber-reinforced-polymeric (FRP) composite system for repair strengthening reinforced concrete (RC) beams. This strengthening system is in the form of thin sandwich FRP panels that are bonded/bolted to concrete. In evaluating this innovative system, experimental and numerical assessment were conducted. In the experimental phase of this study, service and ultimate flexural behavior of three groups of RC beams were evaluated. The three beam specimens of the first group were designated as control specimens and their performance was used as baseline for comparison to the performance of the other two strengthened RC beams groups. The second and third groups comprised of three beam specimens for each group that were externally strengthened with bolted/bonded carbon/phenolic sandwich panels. A nonlinear finite element analysis was performed using LS-DYNA code to simulate and predict the flexural behavior of all RC beam specimens. A numerical parametric study was performed for different simulated cases to assess the effect of several parameters. Numerical results agreed well with the experimental results and test observations. The results of this study indicated that the FRP sandwich panel strengthening systems are effective in enhancing flexural behavior of the strengthened RC beams.