Duplex Zinc Coatings for Corrosion Protection of Steel Structures

Paint is the primary corrosion control strategy for large steel structures, requiring near constant maintenance. Metallic zinc coatings with a paint top-coat, or ‘Duplex Coatings’, offer both barrier and sacrificial corrosion protection mechanisms, with improved impact and abrasion resistance, and much longer lifetimes between maintenance compared to paint only coatings. Duplex coatings provide more than twice the life of the corrosion protection provided by one coating system alone. A paint top-coat over a metallic zinc base layer protects the zinc from initial corrosion. The zinc base layer similarly protects the paint from underfilm corrosion at scratches and holes. The synergy between the two coatings provides protection far superior to either system used independently. Empirical evidence shows that, depending on the environment, duplex zinc coatings will provide 1.5 to 2.3 times the sum of the expected life of each system alone. Duplex zinc coating systems have decades of proven performance protecting steel infrastructure from corrosion.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHD45 Standing Committee on Corrosion.
• Authors:
  • Dallin, Gary
  • Gagné, Martin
  • Goodwin, Frank E
  • Pole, Shannon
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 11p

Subject/Index Terms

• TRT Terms: Corrosion protection; Paint; Steel structures; Zinc coatings
• Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 01663039
• Record Type: Publication
• Report/Paper Numbers: 18-02989
• Files: TRIS, TRB, ATRI
• Created Date: Mar 20 2018 5:08PM