Long-term durability of GFRP internal reinforcement in concrete structures

Omid Gooranorimi, Doug Gremel, John J. Myers, Antonio Nanni

Research output: Contribution to journalConference articlepeer-review


Glass fiber reinforced polymer (GFRP) bars are emerging as a feasible, economical solution to eliminate the corrosion problem of steel reinforcements in concrete structures. Confirmation of GFRP long-term durability is crucial to extend its application especially in structures exposed to aggressive environments. The objective of this study is to investigate the performance of GFRP bars exposed to the concrete alkalinity and ambient condition in two bridges with more than a decade old located in the City of Rolla, Missouri: i) Walker Bridge (built in 1999), which consists of GFRP-reinforced concrete box culverts; and; ii) Southview Bridge (built in 2004), which incorporates GFRP bars in the post-tensioned concrete deck. In order to monitor the possible changes in GFRP and concrete after years of service, samples were extracted from both bridges for various analyses. Carbonation depth, chloride diffusion, 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 horizontal shear strength, glass transition temperature (Tg) and fiber content were determined and compared with the results of similar tests performed on pristine samples produced in 2015. SEM and EDS did not show any sign of GFRP microstructural deterioration or existence of a chemical attack. Horizontal shear strength and Tg showed slight improvements while the fiber content was similar to the pristine values. The results of this study suggest that GFRP bars maintained their microstructural integrity and mechanical properties during years of service as concrete reinforcement in both bridges.

Original languageEnglish (US)
Pages (from-to)69-79
Number of pages11
JournalAmerican Concrete Institute, ACI Special Publication
Issue numberSP 331
StatePublished - 2017
EventDurability of Concrete Structures Incorporating Conventional and Advanced Materials 2017 - Detroit, United States
Duration: Mar 26 2017Mar 30 2017


  • Box-Culvert
  • Bridge Deck
  • Corrosion resistant
  • Durability
  • Glass fiber reinforced polymer
  • Reinforced concrete
  • Scanning electron microscopy

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)


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