Corrosion Prevention of Bridge Tendons Using Flexible Filler Materials

Details

• Creators:
  Presuel-Moreno, Francisco J ; Castaneda, Carlos ; Santillan, Ingrid ; Kazemi, Amirkhosro ; Tang, Fujian
• Corporate Creators:
  Florida Atlantic University. Center for Marine Materials
• Corporate Contributors:
  Florida Department of Transportation
• Subject/TRT Terms:
  Bridges Corrosion Corrosion Tests Electrochemical Corrosion Fillers (Materials) Fungi Posttensioning Tendons (Materials) Waxes Wire
• Publication/ Report Number:
  BDV27-977-10
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida ; United States
• Edition:
  Final, December 21, 2015- November 30, 2028
• Corporate Publisher:
  Florida. Department of Transportation
• Abstract:
  Over the last few decades, flexible fillers such as greases or waxes have been used in Europe as an alternative to cementitious grout. The Florida Department of Transportation (FDOT) is considering flexible fillers as an alternative filler material for post-tensioned (PT) tendons. In this study, the corrosion resistance of these fillers to protect PT tendons was investigated experimentally. Wire or steel strands were coated with flexible filler materials. Selected samples were contaminated with fungi. Three types of fungi were considered, including Fusarium oxysporum (FO), Penicillium chrysogenum (PC), and Aspergillus flavus (AF). The flexible fillers investigated are commercially available microcrystalline waxes. Five different filler types were investigated. Both exposure and electrochemical corrosion tests were designed and performed. Two exposure conditions were considered, including the direct outdoor exposure test and the indoor exposure test. Electrochemical corrosion tests showed that most of the coated strands had impedances higher than 1 Gohm and galvanic corrosion currents lower than 1 nA. However, for the steel strand coated with filler type 3, an increase in the galvanic corrosion current and a decrease in the impedance were observed after two weeks of tests, indicating corrosion initiation. Direct outdoor exposure tests showed that rust was present on steel single wires coated with type 1, type 2, type 3, type 4, and type 5 filler after 20 days, 43 days, 49 days, 114 days, and 126 days of exposure, respectively. Different from the general corrosion observed on wires subjected to direct outdoor exposure tests, localized corrosion was present on indoor wires which were coated with flexible filler and contaminated with fungi. Larger samples were prepared in which the filler was injected into high density polyethylene or polycarbonate tubes. The samples contained from 3 to 19 steel strands. Most samples were also exposed outdoors, and selected samples were periodically sprayed with solutions containing water, or water-fungi mix. Solution was sprayed at 3- to 5-weeks intervals. The corrosion extent on these samples was significantly less.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:45f17617b5777c9cc4f358234c9129f98dc39f05772833477a1748aafcb7cbc0
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/63238/dot_63238_DS1.pdf
• File Type:
  [PDF - 122.06 MB ]