Iowa Department of Transportation
Brent Pharesbphares@iastate.edu email >
Bridge Research Engineer, BEC
Zhengyu Liuzhengyu@iastate.edu email >
Research Engineer, BEC
About the research
This project investigated the long-term protection of steel piles with galvanized and painted galvanized coatings using a corrosion chamber to accelerate corrosion effects in the laboratory. Further investigation was completed through observation of painted galvanized piles installed in the field at a newly constructed bridge in Buchanan County, Iowa.
The primary objective of this research was to evaluate the effectiveness of galvanized and painted galvanized piles in extending bridge service life in a cost-effective manner. An economic evaluation was conducted comparing the use of a larger H-pile section, a galvanized coating, and a painted galvanized coating to protect the piles against corrosion.
One solution to achieve a 100-yr design life is to increase the section size of the pile to allow for section loss without compromising the required pile capacity While the cost to increase the pile size was determined to be less than the premium for galvanizing or galvanizing and painting the piles for the bridge in this study, a cost-benefit evaluation for each protection measure is suggested knowing that costs can vary widely depending on specific project requirements, location, market prices, etc.
An interim report has been published, and the research team plans to continue to collect additional annual data from the Buffalo Creek Bridge in Buchanan County for future analysis.