CASE STUDIES OF TWO NON-OVERLAY CATHODIC PROTECTION SYSTEMS FOR BRIDGE DECKS. FINAL REPORT

Impressed-current cathodic protection systems were installed on two steel-reinforced concrete bridge decks. Primary anodes for both were composites of platinum-niobium wire and conductive polymer grout, bonded into sawed slots in the concrete surface. Secondary anodes were conductive carbon strands and conductive polymer grout bonded into sawed slots. The first installation experienced frequent power-supply malfunctions and significant grout loss. The power supply was replaced, and after 1 1/2 years of service, 10% of the anode matrix was repaired. Surface distress, including concrete delamination and additional grout loss, continued through 3 1/2 years of service. It was then decided to terminate the system, and repair the deck with a conventional high-density concrete overlay. The second installation was four times larger in surface area, and was bid using individual construction items rather than the lump-sum bidding used for the first bridge. Unit cost in this instance was $7.08 per sq ft -- a savings of $2.83 per sq ft. After 2 years, some anode-grout distress and concrete delamination have been experienced, but on a smaller scale. The mechanism of anode-grout distress is examined and differences in construction practices are discussed.

Media Info

  • Features: Appendices; Photos; References; Tables;
  • Pagination: 50 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00493705
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/NY/RR-90/149, Res Rept 149
  • Files: NTL, TRIS, USDOT, STATEDOT
  • Created Date: Apr 30 1990 12:00AM