PERFORMANCE OF EPOXY COATED REBARS IN BRIDGE DECKS

Epoxy coated rebar (ECR) was introduced in the mid 1970s as a means to minimize concrete deterioration caused by corrosion of the reinforcing steel and to extend the useful life of highway structures. This report summarizes the results of investigations performed by highway agencies in the United States and Canada, academia, and the Canadian Strategic Highway Research Program to evaluate the performance of ECR. A total of 92 bridge decks, two bridge barrier rails, and one noise barrier rail was evaluated in the States of California, Indiana, Kansas, Michigan, Minnesota, New York, Ohio, Pennsylvania, Virginia, West Virginia, and Wisconsin, and the provinces of Alberta, Nova Scotia, and Ontario. The overall condition of the bridge decks was considered to be good. Deck cracking did not appear to be corrosion related. Very few of the decks had any delaminations or spalls associated with the ECR. Any delaminations or spalls that were associated with corrosion of ECR were small and generally in isolated locations. No evidence of corrosion was found on 81% of the ECR segments extracted from the structures. The chloride concentrations at the rebar level were generally at or above the threshold to initiate corrosion in black steel. The ECR did not appear to perform as well when the concrete was cracked as when the concrete was not cracked. Corrosion was more severe on ECR segments extracted from locations of heavy cracking, shallow concrete cover, high concrete permeability, and high chloride concentrations. Coating disbondment and softening occurred as a result of prolonged exposure to a moist environment. The number of defects in the epoxy coating and the amount of disbondment appear to influence the performance of ECR. ECR has provided effective corrosion protection for up to 20 years of service. Little or no maintenance or repair work has been performed on the decks. There was no evidence of any significant premature concrete deterioration that could be attributed to corrosion of the ECR. The use of adequate good quality concrete cover, adequate inspection, finishing, and curing of the concrete, and the proper manufacturing and handling of ECR complements the use of ECR in providing effective corrosion protection for concrete bridge decks.

Language

  • English

Media Info

  • Features: References; Tables;
  • Pagination: 104 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00725497
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-RD-96-092, Final Report
  • Files: NTL, TRIS, USDOT
  • Created Date: Sep 3 1996 12:00AM