Repair of the Uphapee Creek Bridge with FRP Laminates

This report describes the strengthening of a fifty-year-old, reinforced concrete bridge using externally bonded, fiber-reinforced polymer (FRP) strips. The three-span, continuous structure is supported by four variable-depth girders. The flexural capacity of each span of the existing structure was insufficient to withstand modern traffic loads. Carbon-fiber-reinforced polymer (CFRP) strips were externally bonded to the girder soffits to enhance the positive moment capacity of each span. The CFRP strengthening system was designed according to ACI 440 recommendations. The report details the installation process as well as a load-testing program utilized to assess the effectiveness of the strengthening system. The installation process was found to be rapid and simple—but exceedingly messy. The structure was load tested on several occasions: once prior to strengthening, once soon after installation of the CFRP, and twice approximately six months after strengthening. The bridge instrumentation measured girder deflections as well as strains in the steel and FRP tension reinforcement. A finite-element model of the bridge was developed to predict theoretical strains for comparison with experimental values. Good agreement was obtained between the experimental and theoretical steel strains in the structure. The reduction in steel strains attributable to the CFRP system corresponded well with the reduction predicted using linear-elastic, cracked-section analysis. Overall, the strengthened bridge behaved as predicted when subjected to truck loads slightly exceeding service-level design loads. The design of the FRP strengthening system is detailed in a companion interim report. Another companion report describes a laboratory test program to investigate the ultimate strength of the CFRP-strengthened girders as well as the effects traffic loads applied during the installation and epoxy-curing period.

• Corporate Authors:

  Alabama Department of Transportation

  1409 Coliseum Boulevard
  Montgomery, AL  United States  36130-3050

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Carmichael, Benjamin M
  • Barnes, Robert W
• Publication Date: 2005-11

Language

• English

Media Info

• Media Type: CD-ROM
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 120p

Subject/Index Terms

• TRT Terms: Bridges; Carbon fibers; Design load; Epoxides; Fiber reinforced plastics; Finite element method; Girders; Laboratory tests; Load tests; Reinforced concrete bridges; Traffic loads
• Uncontrolled Terms: Linear elastic analysis
• Subject Areas: Bridges and other structures; Design; Freight Transportation; Highways; Maintenance and Preservation; I24: Design of Bridges and Retaining Walls; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 01038287
• Record Type: Publication
• Report/Paper Numbers: RP-930-466-2
• Files: TRIS, USDOT, STATEDOT
• Created Date: Dec 26 2006 12:45PM