Corrosion evaluation of novel coatings for steel components of highway bridges.

Details

• Creators:
  Lau, Kingsley ; Sabbir, Md Ahsan
• Corporate Creators:
  Florida International University
• Subject/TRT Terms:
  Ceramic Coatings Corrosion Protection Durability Evaluation Galvanizing Highway Bridges Protective Coatings Steel
• Publication/ Report Number:
  BDV29 977-02
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Corporate Publisher:
  Florida. Dept. of Transportation
• Abstract:
  The Florida Department of Transportation (FDOT) had expressed interest in gauging the available coating
  
  technologies that may have suitable applications for steel components in highway bridges. The motivation was to
  
  possibly identify coating systems that would provide corrosion durability of steel components in highway bridges
  
  and reduce costs associated with regular inspection and maintenance of the coating systems. Chemically
  
  bonded phosphate ceramics (CBPC) and the thermal diffusion galvanizing (TDG) process have been identified
  
  for further testing due to growing interest in the systems for possible corrosion mitigation, the lack of sufficient
  
  data to determine their effectiveness for corrosion protection of steel structures, and their commercial availability.
  
  An issue for further evaluation of long term durability and corrosion protection by CBPC coatings is the degree
  
  of deterioration of the ceramic coating in aggressive environments. Initial testing showed that the material was
  
  not durable in highly alkaline solutions (pH 13), and in exposure conditions that cycle between frequent high
  
  moisture contents and drying conditions. The rather short-term outdoor exposures investigated so far have
  
  produced some promising results, but the significant extent of undercoating surface oxidation that was observed
  
  may compromise long-term durability. The intermediate alloy layer was not consistently identified and its role in
  
  corrosion mitigation has not been elucidated.
  
  Although no severe steel corrosion was observed for TDG in outdoor exposure, degradation of the topcoat,
  
  when present, and subsequent consumption of the TDG would result in a shorter service life of the coating for
  
  corrosion mitigation. Variations in quality of the topcoats resulted in variations in coating performance. The
  
  findings suggest that sufficient application of the TDG and robust topcoats are required for long-term durability.
  
  
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:dc7ecb0c81968229b3988254275e7fb4ef25c11df5bd6621aa3658fcfd6adecc
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28779/dot_28779_DS1.pdf
• File Type:
  [PDF - 15.31 MB ]