Strengthening of Bridge Beams using Fiber Reinforced Polymers (FRP)

A literature review was conducted with regard to fiber reinforced polymer (FRP) strengthening of reinforced concrete bridge beams. The literature review focused primarily on field applications and analytical and design considerations. Selected laboratory investigations related to field implementation projects are also included in the literature review. Based on the literature review and the experience of the investigators, three different strengthening systems were selected for implementation on an existing bridge in Baton Rouge, Louisiana. The design of the three strengthening systems involving carbon fiber reinforced polymers (CFRP) wet layup, CFRP pre-cured plates, and near surface mounted CFRP rods and their installation on spans two and three of the White Bayou Bridge in Zachary, Louisiana, are described in detail. The moment capacity of the CFRP strengthened beams increased from 15% to 32% depending on the system used. The shear capacity of the member was not an issue. The live load testing and installation of the long term monitoring system were carried out by Bridge Diagnostics Inc. (BDI) and are discussed in this report (See Appendix A). The bridge was instrumented with several strain and displacement sensors and the first set of live load tests were conducted before the bridge was strengthened using three different load paths. The second set of tests was performed with identical procedures to the first load test so that direct comparisons of the response could be made. The load tests permitted the assessment of the lateral load distribution that occurred in the structure and the confirmation that continuity was minimal. The member capacities that were calculated using the Standard Specifications for Highway Bridges, and the load rating factors for the standard AASHTO H-20, HS-20, Type 3, Type 3-3, and Type 3S3 vehicles that were computed according to the LFD rating method are presented in this report. The ultimate moment capacity of the strengthened beams and the associated load rating factors for each of the strengthening systems were calculated and compared with the un-strengthened member values. Recommendations for the installing of the CFRP reinforcement, factors to be considered in field monitoring and load testing, and a summary related to the cost of the FRP strengthening systems and the relative performance of each system are included.

• Record URL:
  http://www.ltrc.lsu.edu/pdf/2016/FR%20384_print%20ready_in%20full.pdf
• 
• Summary URL:
  http://www.ltrc.lsu.edu/pdf/03_4ST.pdf
• Corporate Authors:

  Louisiana State University, Baton Rouge

  Department of Civil and Environmental Engineering
  Baton Rouge, LA  United States  70803

  Louisiana Department of Transportation and Development

  1201 Capitol Access Road, P.O. Box 94245
  Baton Rouge, LA  United States  70804-9245

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Gopu, Vijay
  • Ziehl, Paul H
• Publication Date: 2016-11

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 224p

Subject/Index Terms

• TRT Terms: Beams; Bridges; Carbon fibers; Costs; Fiber reinforced polymers; Literature reviews; Load tests; Reinforced concrete; Structural strengthening
• Uncontrolled Terms: Load rating (Bridges)
• Geographic Terms: Baton Rouge (Louisiana)
• Subject Areas: Bridges and other structures; Design; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 01618831
• Record Type: Publication
• Report/Paper Numbers: FHWA/LA.16/384
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Dec 17 2016 8:17PM