Review of the Properties of Fiber-Reinforced Polymer-Reinforced Seawater–Sea Sand Concrete

Fiber-reinforced polymer (FRP)–reinforced seawater–sea sand concrete (SWSSC) is a new structure form for coastal infrastructure, especially for island construction. The degradation mechanism of FRP bars in SWSSC involves water molecules, hydroxide ions, chloride ions, high temperature, and stress. In general, water molecules and hydroxide and chloride ions react with some ingredients in FRP bars, destroy the interface between fiber and resin, and reduce the properties of FRP bars. In the environment of water molecules, hydroxide ions, and chloride ions, the strength retentions of FRP bars were 71%–77%, 26%–98%, and 49%–77%, respectively, depending on composition and manufacturing techniques of fiber. High temperature and stress accelerate the degradation of FRP bars. Under different temperatures and stress levels, the strength retentions of FRP bars were 0.6%–98% and 43%–93%, respectively, depending on the fiber type, temperature, and stress levels. The presence of chloride ions accelerates the hydration of cement and improves the properties of SWSSC at early age. However, the conclusions on the properties of SWSSC at later age are still controversial. Based on previous studies, some future needs on FRP-reinforced SWSSC are also recommended.