Assessment of weathering steel bridge performance in Iowa and development of inspection and maintenance techniques.

Details

• Creators:
  Crampton, Douglas D. ; Holloway, Kurt P. ; Fraczek, John
• Corporate Creators:
  Wiss, Janney, Elstner, and Associates
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Weathering steel
  • Steel bridges
  • Inspection
  • Maintenance
  • Bridge superstructures
  • Corrosion
  • Deicing chemicals
  • Chlorides
• Publication/ Report Number:
  5300C
• Resource Type:
  Tech Report
• Geographical Coverage:
  Iowa
• Corporate Publisher:
  Iowa. Dept. of Transportation. Office of Bridges and Structures
• NTL Classification:
  NTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and Structures ; NTL-HIGHWAY/ROAD TRANSPORTATION-Construction and Maintenance
• Abstract:
  Weathering steel is commonly used as a cost-effective alternative for bridge superstructures, as the costs and environmental ; impacts associated with the maintenance/replacement of paint coatings are theoretically eliminated. The performance of ; weathering steel depends on the proper formation of a surface patina, which consists of a dense layer of corrosion product used to ; protect the steel from further atmospheric corrosion. The development of the weathering steel patina may be hindered by ; environmental factors such as humid environments, wetting/drying cycles, sheltering, exposure to de-icing chlorides, and design ; details that permit water to pond on steel surfaces. ; Weathering steel bridges constructed over or adjacent to other roadways could be subjected to sufficient salt spray that would ; impede the development of an adequate patina. Addressing areas of corrosion on a weathering steel bridge superstructure where a ; protective patina has not formed is often costly and negates the anticipated cost savings for this type of steel superstructure. Early ; detection of weathering steel corrosion is important to extending the service life of the bridge structure; however, written ; inspection procedures are not available for inspectors to evaluate the performance or quality of the patina. This project focused on ; the evaluation of weathering steel bridge structures, including possible methods to assess the quality of the weathering steel patina ; and to properly maintain the quality of the patina. The objectives of this project are summarized as follows: ;  Identify weathering steel bridge structures that would be most vulnerable to chloride contamination, based on location, ; exposure, environment, and other factors. ;  Identify locations on an individual weathering steel bridge structure that would be most susceptible to chloride contamination, ; such as below joints, splash/spray zones, and areas of ponding water or debris. ;  Identify possible testing methods and/or inspection techniques for inspectors to evaluate the quality of the weathering steel ; patina at locations discussed above. ;  Identify possible methods to measure and evaluate the level of chloride contamination at the locations discussed above. ;  Evaluate the effectiveness of water washing on removing chlorides from the weathering steel patina. ;  Develop a general prioritization for the washing of bridge structures based on the structure’s location, environment, ; inspection observations, patina evaluation findings, and chloride test results.
  More +
• Format:
  PDF
• Funding:
  SPR 90-00-RB17-012
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/26348/dot_26348_DS1.pdf
• File Type:
  [PDF - 10.25 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:cccebe3f1dd2e39c989412d03b6825ba55bb09274db107be3fead898dca0f965