Physicochemical-mechanical simulation of the short- and long-term performance of FRP reinforced concrete beams under marine environments

To broaden the applications of fiber reinforced polymer (FRP) reinforced concrete structures under marine environments, it is crucial to gain a fundamental understanding of their short- and long-term performance. In this study, the effectiveness of the proposed multi-scale simulation platform, which incorporates the proposed degradation model of FRP bars, is quantitatively assessed via the comparison between the predicted results and experimental load-displacement curves under different marine conditions (continuous immersion, wet-dry cycling and subtropical marine atmosphere). The spatially physical, chemical and mechanical information, such as pH value, moisture, hydration degree, strength, porosity during the exposure was also revealed. Finally, the long-term structural performance of FRP-reinforced concrete beams exposed to the predefined environmental conditions over durations of 20, 50 and 100 years are assessed using the multi-scale simulation platform. After 50 years of exposure, the load-bearing capacity of GFRP-reinforced concrete beams was found to decrease by 35.8 % in immersion conditions and by 17.9 % in subtropical marine atmosphere. The degradation of the load-bearing capacity in the case of 100 years exposure to subtropical marine atmosphere was found to be less severe than that (23.1 %) in the case of 50-year immersion. These findings not only deepen our understanding of the material and structural properties of FRP-reinforced concrete beams under various environmental conditions, but also validate the effectiveness of the proposed multi-scale platform.