Long-term performance of GFRP reinforcement : technical report.

Details

• Creators:
  Trejo, David ; Gardoni, Paolo ; Kim, Jeong Joo ; Zidek, Jason
• Corporate Creators:
  Texas Transportation Institute
• Corporate Contributors:
  Texas. Dept. of Transportation. Research and Technology Implementation Office
• Subject/TRT Terms:
  • Glass fiber reinforced plastics
  • Reinforcing bars
  • Fiber reinforced concrete Glass-reinforced plastics--Evaluation
  • Reinforcing bars--Evaluation.
  • Fiber-reinforced concrete--Evaluation
• Publication/ Report Number:
  FHWA/TX-09/0-6069-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Edition:
  Technical report; Sept. 2007-Aug. 2008.
• Corporate Publisher:
  Texas Transportation Institute
• Abstract:
  Significant research has been performed on glass fiber-reinforced polymer (GFRP) concrete reinforcement. ; This research has shown that GFRP reinforcement exhibits high strengths, is lightweight, can decrease time of ; construction, and is corrosion resistant. Regarding the corrosion resistance, research has shown that the chemical ; reactions that occur in GFRP bars do not result in expansive products—products that can damage the concrete ; surrounding the reinforcement. Although not classical steel corrosion, much research that has been performed ; shows that GFRP reinforcing bars do corrode, reducing the tensile capacity of the GFRP reinforcing bars as a ; function of time. The American Concrete Institute (ACI) recognized this and places a reduction factor on the ; allowable design strength of GFRP reinforcing bars. A drawback of the majority of the research is that GFRP ; reinforcing bars have typically been directly exposed to aggressive solutions, exposure conditions possibly not ; similar to the exposure they would encounter while embedded in concrete. Limited research has been performed ; evaluating the tensile capacity reduction of bars embedded in concrete; however, these bars were only exposed for ; relatively short durations. ; This research investigated the characteristics of GFRP reinforcing bars embedded in concrete for 7 years and ; exposed to a mean annual temperature of 69 oF (23 oC) and an average precipitation of 39.7 inches (1008 mm), ; fairly evenly distributed throughout the year. Three manufacturers provided #5 and #6 bars for this research. ; Results indicate that GFRP reinforcing bars do exhibit reduced capacities when embedded in concrete. A model ; was developed to assess the tensile capacity of bars embedded in concrete. The model was based on a general ; diffusion model, where diffusion of water or ions penetrate the bar matrix and degrade the glass fibers. The model ; is dependent on time, diffusion characteristics of the matrix material, and the radius of the GFRP reinforcing bar. ; The model indicates that GFRP reinforcement bars with larger diameters exhibit lower rates of capacity loss. ; However, the times required for the tensile capacity of the GFRP bars to drop below the ACI design requirements ; for #3, #5, and #6 bars were less than 6 years. Further research is needed to determine how this will affect the ; design of GFRP-reinforced concrete structures; however, consideration of changing the ACI design requirement ; may be warranted.
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• Format:
  PDF
• Funding:
  Project 0-6069
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17628/dot_17628_DS1.pdf
• File Type:
  [PDF - 7.28 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:738e383afcb2dfcdbe2a0978f6201b27ae3718cd90e5aceeb2130b5bb5ba21dab6b9e0f1650913022f3e70e3ed395e5122a9b6e5bf60010376011f6b3d231486