Since the use of steel reinforcement is related to corrosion issues, other alternatives needed to take place to mitigate the corrosion problems. One of these alternatives is glass fiber (GFRP). It presents itself as a strong candidate to replace steel reinforcement due to not only its high resistivity to corrosion, but also its economic efficiency. The goal of this study is to assess the performance of GFRP bars implanted in two bridges and exposed to a real-time weather environment for over ten years. The bridges are Southview Bridge in Missouri and Sierrita de la Cruz Creek in Texas. Cores were extracted from each bridge containing some parts of GFRP reinforcement. Several tests were conducted on the GFRP bars and surrounding concrete. These tests include: scanning electron microscopy, energy dispersive spectroscopy, short bar shear, fiber content, pH, chloride content, and carbonation depth. Regarding the results, scanning electron microscopy showed no existence of microstructural degradation in the glass fiber and interfacial transition zone. Energy dispersive spectroscopy did not show any changes in the GFRP's chemical composition. However, short bar shear showed some changes from control bars. The outcome of this research provides new evidences that can be used to enhance GFRP durability data in civil engineering codes and standards.