Feasibility of applying cathodic protection to underground culverts.

Details

• Creators:
  Garber, J. D. ; Lin, J. H. ; Smith, L. G.
• Corporate Creators:
  University of Southwestern Louisiana. Dept. of Civil Engineering
• Corporate Contributors:
  Louisiana. Dept. of Transportation and Development
• Subject/TRT Terms:
  Cathodic Protection Coating Coatings Corrosion Culvert Current Economic Metal Culverts Potential
• Publication/ Report Number:
  FHWA/LA-91/238
• Resource Type:
  Tech Report
• Geographical Coverage:
  Louisiana
• Corporate Publisher:
  Louisiana. Dept. of Transportation and Development
• Abstract:
  The Louisiana Department of Transportation and Development uses metal culverts in various parts of the state. This study was undertaken to assess the feasibility of applying cathodic protection both externally and internally to metal culverts to prevent corrosion from occurring. The methodology employed ranged from a variety of laboratory tests to an actual field study. The laboratory tests were conducted: (1) to determine the best coating system to use in conjunction with cathodic protection and (2) to prove that internal cathodic protection would work inside 24-inch culverts using zinc anodes. The field work consisted of installing 10-foot sections of eight different types of culverts with and without cathodic protection. Current and potential measurements have been made during the first two years of this four-year study. The results of the field study have proven that culverts can be protected from corrosion economically using cathodic protection. It has been found that the outside of the culvert requires significantly more current for protection than does the inside. All of the unprotected culverts are experiencing corrosion, and the culvert requiring the least amount of current is the polymeric galvanized steel. The only laboratory test that was able to predict the best coating system on galvanized steel was the 13-gallon water tank test using magnesium anodes. The more sophisticated tests, potentiostat and impedance, were unable to make good predictions. It is recommended that cathodic protection be applied to culvert systems that are in low resistivity environments. Culverts being installed in new locations should be electrically connected so that cathodic protection can be more easily applied later.
• Format:
  PDF
• Funding:
  La.HPR Study #88-4P(B)
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:286ad817bf2177a9bb1096d4d7fd920bc91cf82563de98317a507e9fead5fe60
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/22111/dot_22111_DS1.pdf
• File Type:
  [PDF - 11.16 MB ]