Advances in durability of FRP bars under alkaline environment

Fiber Reinforced Polymer (FRP) bar is a new construction material with light weight, high tensile strength and strong resistance to corrosion. FRP bars are increasingly used instead of steel bars to solve corrosion problems in reinforced concrete structures. But researchers gradually realize that FRP bars are prone to be corroded under harsh environment. FRP bars embedded in concrete for several years are exposed to an alkaline environment with aggressive ions that may cause a loss in mechanical properties. The paper introduces the progress of the durability of FRP bars under alkali environment, especially analyses the degradation mechanism of FRP bars under alkali environment. In addition, a theoretical model predicting the influence on durability of FRP rods in alkaline solutions is given and future study trend on durability of FRP rods is discussed.