Oxygen Permeability of FRP-Concrete Repair Systems

Abstract

Fiber reinforced polymers (FRP) are increasingly used for repairing corrosion-damaged concrete structures. The performance of the repairs is critically dependent on the oxygen permeability of the FRP-concrete system. This paper presents the results of an experimental study in which the oxygen permeation of concrete and FRP-concrete systems were determined. In the study, concrete specimens with three different water-cementitious ratios were initially tested. Subsequently, uni directional one and two-layer carbon and fiberglass material were bonded to the concrete surface, and the oxygen permeation of the FRP-concrete systems were determined. The results showed a significant reduction in the oxygen permeation of concrete after FRP had been bonded. The best performance was obtained for FRP bonded to concrete with the highest water-cementitious ratio. An expression for the equivalent thickness of FRP-concrete systems was derived by using Fick’s law. This facilitates the evaluation of the effectiveness of alternate FRP-concrete corrosion repair schemes.