Development of FRP (Fiber Reinforced Polymer) for Rehabilitation of Marine Concrete Structure

The durability of marine concrete structures has long been a concern of many countries, especially in the island country of Singapore, where many structures are constructed along coastal areas. Currently, the durability of concrete under marine conditions can be enhanced by the addition of admixtures, and using high grade concrete. The FRP system can also be used to increase the durability of the concrete structures under marine conditions, by preventing the ingress of chloride ions into the structures, thereby preventing the corrosion of the steel reinforcements. In addition, the FRP system has the additional function of increasing the strength of the structure. The FRP system, which composed of the epoxy developed and carbon fiber selected, was evaluated according to various standard testing methods to get the basic technical information of the FRP system. Full scale laboratory testing was carried out to determine the effectiveness of the FRP in enhancing the structural performance of concrete structures. Test results showed that the structural capacity of concrete beams can be increased, with the addition of the FRP system. A total of 8 marine structures (4 beams, 3 slabs and 1 pile cap) were chosen for installation and monitoring at the Port of Singapore Authority site. Results show that the corrosion rates were lower than the unwrapped (control) structures. It was also observed that the FRP wrapped structures had no durability problems under marine conditions. In addition, structural health monitoring was conducted using a system of Fiber Optic Sensors (FOS). Structural Monitoring results showed that beams wrapped with the FRP exhibited greater reductions in strain.