Structural steel coatings for corrosion mitigation.

Details

• Creators:
  Meyers, John J. ; Zheng, Wei ; Washer, Glen
• Corporate Creators:
  Missouri University of Science and Technology
• Subject/TRT Terms:
  Bridges Bridges--Missouri--Testing Coatings Corrosion Precast Concrete Structural Steel
• Publication/ Report Number:
  NUTC R233 ; NUTC R238
• Resource Type:
  Tech Report
• Geographical Coverage:
  Missouri
• Edition:
  Final report.
• Corporate Publisher:
  Missouri University of Science and Technology
• Abstract:
  Task 1 of this project was to survey the performance of coating systems for steel bridges in Missouri and to evaluate coating and
  
  recoating practices. Task 1 was led under the direction of Dr. Glenn Washer from the University of Missouri located in Columbia,
  
  MO. A specific literature review focused on current state-of-the-practice for overcoatings, bridge coating assessment and rating,
  
  deterioration rate modeling as well as the risk assessment for overcoating. A new coating evaluation guideline was created to meet the
  
  needs of bridge maintenance in Missouri. Finally a field survey was carried out onto the existing bridge coatings across 10 Missouri
  
  Department of Transportation (MoDOT) districts and 26 counties. It was found that system S and G perform very well in many of the
  
  situations observed. The survey indicated that in many cases system S overcoatings are providing service life extension for the coating
  
  system, with some early failures resulting from severe exposure to deck drainage and corrosion. Deck condition, drainage, and joint
  
  conditions were found to be the dominate factor in deterioration of the coating system, regardless of the age of the coating. Task 2 of
  
  this project investigated the performance of new types of coating technologies on bridge corrosion mitigation and was led under the
  
  direction of Dr. John Myers from the Missouri University of Science and Technology located in Rolla, MO. Twelve coating systems
  
  including MoDOT system G were evaluated through several laboratory tests to study and predict the field performance and durability
  
  of new coating technologies. The new coating systems investigated in this study involved polyurea, polyaspartic polyurea,
  
  polysiloxane polymers and fluoropolymer. To date, these coating system technologies have not been used as a steel structural coatings
  
  system in the State of Missouri by MoDOT. The laboratory tests consist of freeze-thaw stability, salt fog resistance, QUV weathering
  
  and electrochemical tests. The comparison study was carried out to benchmark and understand the pros and cons of these new coating
  
  systems. In addition, two coating systems served as overcoating studies for lead-based paint systems representative of older existing
  
  bridges in the state of Missouri. These overcoating systems were evaluated using an accelerated lab test method and electrochemical
  
  test. The performance of the existing MoDOT calcium sulfonate (CSA) overcoating system (system S) was also studied within the test
  
  matrix for comparative purposes. The test results show that moisture cured urethane micaceous iron oxide zinc/polyurea polyasp
  
  is a promising coating system for recoating of new steel
  
  artic
  
  bridges and that aliphatic polyaspartic polyurea can also be applied on
  
  existing coatings after the surface is properly prepared.
  
  
• Format:
  PDF
• Funding:
  DTRT06-G-0014
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:c0fecfcd07555075aa42f44aa6a546fcbe954b6d5eb2c6541d0d3d3980b7a140
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18352/dot_18352_DS1.pdf
• File Type:
  [PDF - 74.22 MB ]