Accelerated and Natural Weathering of Glass Fiber Reinforced Plastic Bars

Strength and stiffness properties of Glass Fiber Reinforced Plastic (GFRP) bars under various conditioning schemes with and without the application of sustained loads are described in this paper. Alkaline conditioning was more detrimental to the strength of GFRP bars as compared to salt conditioning. Increasing temperatures and stress resulted in a corresponding decrease in the strength of GFRP bars. Based on accelerated test results calibrated with respect to naturally aged results it is safe to include that the service life of the FRP bars with durable low viscosity urethane modified vinylester resin is about 60 years as a minimum with 20% sustained stress on the bar. Concrete cover protection on the GFRP bars enhanced the service life up to an additional 60 years.