A new fire resistant FRP for externally bonded concrete repair

Fiber reinforced polymer (FRP) composites, as a mature technology, have been widely used to repair/retrofit/reinforce damaged/degraded concrete structures such as steel reinforced concrete (RC) beams or columns by externally bonding FRP sheet(s) onto the surface of substrate concrete structures. However, the performance of FRP systems exposed to fire is a serious concern due to the combustibility of FRPs. The objective of this study is to understand and develop a new fire resistant technology with nanoclay reinforced intumescent coating. RC beams were prepared, damaged, and repaired by FRP with the new coating. The repaired RC beams were subjected to fire hazard again, and re-evaluated for its residual structural capacity. The effectiveness of the developed new coating for fire resistance was evaluated based on the test results. It is believed that this coating system would enhance fire resistance of the FRP, and safety and reliability of FRP repaired concrete structures.

► A nanoclay reinforced FRP was prepared for fire tolerance.
► A combination of nanocomposite with fire resistant coating was investigated.
► Nanocomposite shows improvement in fire tolerance.
► Fire resistance coating further enhances fire tolerance of nanocomposite.
► It may be a potential technology for resisting fire hazard in FRP repaired RC structures.