Tensile properties degradation of glass fiber-reinforced polymer bars embedded in concrete under severe laboratory and field environmental conditions

This paper presents the test results of an experimental study to investigate the durability of newly developed glass fiber-reinforced polymer bars. The main objective of this study is to investigate any degradation in the tensile properties of the glass fiber-reinforced polymer bars using accelerated aging methods. Glass fiber-reinforced polymer bars were embedded in concrete prisms and exposed to several environmental conditions for 6, 12, and 18 months. The environments included exposure to tap water and seawater at two temperatures (room temperature and 50 C), seawater dry/wet cycles and alkaline solution at 50 C. In addition, two typical field conditions of the Kingdom of Saudi Arabia (Gulf area and Riyadh area) were included. The performance of the glass fiber-reinforced polymer bars was evaluated by conducting tensile tests on the bars extracted out from the concrete prisms after exposure to different conditions. In addition, scanning electron microscope was used to investigate the degradation mechanism of the bars. After 18 months of exposure, test results showed that both the tap water at 50 C and the alkaline solution at 50 C had the maximum harmful effect on the tensile strength of glass fiber-reinforced polymer bars. The two field conditions showed almost no degradation in the tensile properties of the tested bars.