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DTRT13-G-UTC45, Glass fiber reinforced polymer (GFRP) composites are emerging as a feasible economical solution to eliminate the, corrosion problem of steel reinforcements in the concrete industry. Confirmation of GFRP long-term durability is crucial, to extend its application in aggressive environments. The objective of this study is to investigate the performance of, GFRP materials exposed to the concrete alkalinity and ambient conditions after 15 years of service in a field application., “Sierrita de la Cruz Creek” Bridge (built in 2000, located 25 miles Northwest of Amarillo, Texas) was chosen as a case, study since it was one of the first bridges that included GFRP as both primary and secondary top mat reinforcements in, the deck. In order to monitor possible changes in GFRP and concrete after fifteen years of service, samples were extracted, from different locations on the bridge for various analyses. Carbonation depth and pH of the concrete surrounding the, GFRP bars were measured. Scanning electron microscopy (SEM) imaging and energy dispersive X-Ray spectroscopy, (EDS) were performed to monitor any microstructural degradation or change in the GFRP chemical compositions., Finally, GFRP interlaminar (horizontal) shear strength, glass transition temperature (Tg) and fiber content were, determined and compared with the results of similar tests performed on control samples at the time of construction. SEM, and EDS did not show any sign of GFRP microstructural deterioration or change of chemical composition. Inter-laminar, shear strength results were inconclusive as the No. 5 showed a slight improvement, while the strength of No. 6 decreased., Tg and fiber content were comparable to pristine values. The results of this study represent an additional data point to, validate the notion that GFRP bar properties are maintained during 15 years of service as concrete reinforcement in a field, application.

USDOT: DTRT13-G-UTC45, Project #00042134-04-103A103(A), Glass fiber reinforced polymer (GFRP) composites are emerging as a feasible economical solution to eliminate the corrosion problem of steel reinforcements in the concrete industry. Confirmation of GFRP long-term durability is crucial to extend its application in aggressive environments. The objective of this study is to investigate the performance of GFRP materials exposed to the concrete alkalinity and ambient conditions after 15 years of service in a field application. “Sierrita de la Cruz Creek” Bridge (built in 2000, located 25 miles Northwest of Amarillo, Texas) was chosen as a case study since it was one of the first bridges that included GFRP as both primary and secondary top mat reinforcements in the deck. In order to monitor possible changes in GFRP and concrete after fifteen years of service, samples were extracted from different locations on the bridge for various analyses. Carbonation depth and pH of the concrete surrounding the GFRP bars were measured. Scanning electron microscopy (SEM) imaging and energy dispersive X-Ray spectroscopy (EDS) were performed to monitor any microstructural degradation or change in the GFRP chemical compositions. Finally, GFRP interlaminar (horizontal) shear strength, glass transition temperature (Tg) and fiber content were determined and compared with the results of similar tests performed on control samples at the time of construction. SEM and EDS did not show any sign of GFRP microstructural deterioration or change of chemical composition. Inter-laminar shear strength results were inconclusive as the No. 5 showed a slight improvement, while the strength of No. 6 decreased. Tg and fiber content were comparable to pristine values. The results of this study represent an additional data point to validate the notion that GFRP bar properties are maintained during 15 years of service as concrete reinforcement in a field application.