Freeze-Thaw Behavior of FRP-Confined Concrete under Sustained Load

Abstract

Synopsis: Fiber-reinforced polymers (FRPs) are effective in strengthening concrete structures. However, little work has examined the effects of cold regions on the behavior of the strengthened members, particularly the combined effects of sustained loading and freeze-thaw exposure. This paper presents the results of an experimental study on the durability of 70 normal weight, low strength, and non-air entrained concrete cylinders (150 x 300mm). The cylinders were confined with glass-FRP (GFRP) sheets or carbon-FRP (CFRP) sheets and exposed to 300 freeze-thaw cycles while under sustained axial compression loads. FRP-wrapped cylinders showed exceptional durability performance after their extreme exposure to freeze-thaw and sustained loading with a maximum of 12% reduction in strength. Some CFRP wrapped cylinders that were exposed to freeze-thaw without longitudinal restraint, by means of sustained loads, and all the plain concrete cylinders were completely disintegrated with virtually zero residual strength.