The Behavior of Heat-Damaged RC Beams Reinforced Internally with CFRP Strips

Abstract

When an RC (reinforced concrete) structure is prone to a very high temperature, the structure severely deteriorates; the reasons for this are: a) the degradation in the products of the cement hydration, b) the production of vapor’s pressure, and c) the incompatible change in the volumes of the components of concrete when the temperature is higher than 500 °C. Nevertheless, the structures damaged severely by excessive heat can be greatly able to re-have their original performance and qualities back if they are strengthened in shear with laminated CFRP (a short form for carbon fiber-reinforcement polymers) composites. However, the efficiency of this method is menaced because of two setbacks: 1) delamination, and 2) anchorage. This method aimed to examine its efficacy in reinforcing-in-flexural concrete beams, whether mainly or additionally, prior to and post being exposed to very high temperatures. In this paper, the study parameters were: 1) the CFRP sheet’s length of CFRP; and 2) the exposed temperature. Also, the researchers took into consideration to monitor: the structure’s behavior, the ultimate capacity of loading, the correspondent-to-loading deflections, toughness, and elastic stiffness. This research paper found that using internally installed sheets of CFRP for flexural strengthening proved to be highly efficient in damaged-by-heat RC beams.