This paper presents mechanical, microstructural, and physical characterization of glass fiber-reinforced polymer GFRP bars
exposed to concrete environment. GFRP bars were embedded in concrete and exposed to tap water at 23, 40, and 50°C to accelerate the
effect of the concrete environment. The measured tensile strengths of the bars before and after exposure were considered as a measure of
the durability performance of the specimens and were used for long-term properties prediction based on the Arrhenius theory. In addition,
Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy were used to characterize the
aging effect on the GFRP reinforcing bars. The results showed that the durability of mortar-wrapped GFRP bars and exposed to tap water
was less affected by accelerated aging than the bars exposed to simulated pore-water solution. These results confirmed that the concerns
about the durability of GFRP bars in concrete, based on simulated laboratory studies in alkaline solutions, do not properly correspond to
the actual service life in concrete environments.