Fire endurance of fiber-reinforced polymer strengthened concrete T-Beams

Understanding the performance of fiber-reinforred polymer (FRP)-strengthened members in fire is critical to the widespread application of FRPs as repair materials for infrastructure. An investigation was undertaken to examine and document the performance of FRP-strengthened reinforced concrete T-beams under standard fire conditions. Two full-scale reinforced concrete T-beams were strengthened in flexure with FRP sheets and insulated with a patented two-component fire insulation system. The specimens were subsequently exposed to a standard fire under full sustained service load. Member deflections, strain in the steel reinforcement, and temperatures throughout the section were measured and recorded throughout the tests. A numerical heat transfer model was used to predict temperatures within the section at any time during the fire. The predicted temperatures are compared with those observed during the fire tests and are shown to agree satisfactorily. The results indicate that appropriately designed and insulated FRP-strengthened reinforced concrete T-beams can achieve fire endurances of more than 4 hours.