CORROSION OF EPOXY COATED REBAR IN FLORIDA BRIDGES. FINAL REPORT

The purpose of this investigation was to determine the present condition of Florida bridges built with Epoxy-Coated Rebar (ECR), and to establish a prognosis for the future corrosion-related durability of these structures. There are over 300 bridges built with ECR in Florida, and the observation of severe corrosion at five major bridges using ECR in the Florida Keys created concern about the condition of the rest and their expected durability. About 30 large bridges were selected for detailed examination, including a few plain rebar structures for comparison. Field examinations and laboratory tests were conducted, and a computational model was applied to predict the time to development of corrosion spalls in the structures examined. The model was based on the field and laboratory studies and on chloride penetration measurements. The prognosis of corrosion performance indicated that about one third of the structures examined can be expected to experience service spans approaching or exceeding the current 75-year design goal before extensive corrosion-related repairs are needed. Another third includes bridges that might begin to show signs of corrosion distress within the next decade. Bridges in the remaining third (some of which are already showing damage) should be monitored frequently for possibility of immediate repair needs. The extended life of the best performing group is ascribed primarily to the concrete quality and concrete cover depth used, and not to the presence of ECR. The experience in the Florida Keys suggests that in cases of highly permeable concrete the use of ECR did not provide significant additional protection. The investigation results also indicated that materials guidelines emphasizing the use of low permeability concrete, and construction design guidelines specifying ample rebar cover, are the most practical approach to attain long term durability in Florida marine substructure service. The ECR structures presently undergoing corrosion will necessitate continuing attention. Newly acquired results continue to support the use of sacrificial sprayed zinc anodes as a cost-effective alternative to simple gunite repairs of the presently corroding ECR structures.

  • Corporate Authors:

    University of South Florida, Tampa

    Department of Civil and Environmental Engineering, 4202 East Fowler Avenue
    Tampa, FL  United States  33620

    Florida Department of Transportation

    P.O. Box 1029
    Gainesville, FL  United States  32602
  • Authors:
    • Sagues, Alberto A
    • Lee, J B
    • Chang, X
    • Pickering, H
    • Nystrom, E
    • Carpenter, W
    • Kranc, S C
    • Simmons, T
    • Boucher, B
    • Hierholzer, S
  • Publication Date: 1994-5

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 135 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00662775
  • Record Type: Publication
  • Report/Paper Numbers: WPI No. 0510603, State Job 99700-7556-010
  • Files: TRIS, STATEDOT
  • Created Date: Jul 1 1994 12:00AM