9.3.3 Durability considerations—Durability of FRP systems is the subject of considerable ongoing research (Steckel et al. 1999). The licensed design professional should select an FRP system that has undergone durability testing consistent with the application environment. Durability testing may include hot-wet cycling, alkaline immersion, freezing-and-thawing cycling, ultraviolet exposure, dry heat, and salt water.
Any FRP system that completely encases or covers a concrete section should be investigated for the effects of a variety of environmental conditions including those of freezing and thawing, steel corrosion, alkali and silica aggregate reactions, water entrapment, vapor pressures, and moisture vapor transmission (Masoud and Soudki 2006; Soudki and Green 1997; Porter et al. 1997; Christensen et al. 1996 ; Toutanji 1999). Many FRP systems create a moistureimpermeable layer on the surface of the concrete. In areas where moisture vapor transmission is expected, adequate means should be provided to allow moisture to escape from the concrete structure.