Details:

Creators:
Lau, Kingsley ; Sabbir, Md Ahsan
Lau, Kingsley ; Sabbir, Md Ahsan Less -
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:

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