Bridge engineers choose weathering steel for its performance, economical and environmental benefits. Weathering steels contain elements that allow them to form a protective coating patina or coating when properly exposed to the atmosphere. The first bridge using this material was built over the New Jersey Turnpike in 1964.
The use of uncoated weathering steel typically provides initial cost savings of 10 percent or more, and life cycle cost savings of at least 30 percent over the life of the structure. Initial cost savings are realized because weathering steels do not need to be painted. Life cycle cost savings are realized by the material’s durability. Inspections of bridges in service between 18 and 30 years show that weathering steel performs well in most environments.
Weathering steels provide environmental benefits as well. They do not require initial painting, thereby reducing emissions of volatile organic compounds (VOC) when oil-based coatings are used. They do not require coating removal or disposal of contaminated blast debris over the life span of the structure, providing another significant environmental benefit.
A comprehensive research report on the performance of weathering steel bridges in West Virginia is available here.