Over the river and through the woods
Not much thought is given to what actually gets one over the river to grandma’s house, but bridges are an integral part of the nation’s infrastructure. In West Virginia alone, there are some 6,500 bridgesmade of everything from wood to steal. West Virginia University’s Department of Civil and Environmental Engineering, in cooperation with the Federal Highway Administration and the West Virginia Division of Highways (DOH), have undertaken a project to evaluate the state’s 100 weathering steel bridges.
Weathering steel is different from traditional steel in that it is created by taking traditional steel and combining it with copper, phosphorus, chromium and silicon. This combination significantly increases the corrosion resistance of the steel. As a result, weathering steel is typically not painted, which provides substantial cost savings to the DOH . For this reason, weathering steel is becoming the material of choice for new steel bridges in the state, especially with growing environmental concerns and regulations regarding painted structures.
As weathering steel is becoming used more frequently, the state highways department has initiated a research project to ensure that the weathering steel bridges in the state are performing as intended, and that there are no corrosion problems resulting from the use of the non painted weathering steel.
“The DOH has asked us to evaluate a representative sample from the inventory of West Virginia’s weathering steel bridges. These bridges will be evaluated through on site visits and categorized so that general trends can be identified,”said Dr. Karl Barth, professor of civil and environmental engineering at WVU and lead researcher on the project.
So far, Barth along with civil engineering graduate student Jennifer Righman, and Dr. Pedro Albercht, a professor at the University of Maryland, have evaluated approximately 20 bridges, mainly in the north central part of the state but also including the New River Gorge Bridge.
“When we visit each bridge, we want to identify a couple of things,”Barth said.”They include what the bridge is crossing, for example water, railroads, roads or any combination of the three, and how old the bridge is. We are particularly interested in older bridges because the steel has been exposed for the longest amount of time, so they are likely to be the worst cases. On the other hand we are interested in the newer weathering steel bridges to assess the influence of current construction practices on the weathering steel performance.”
The team also looks for areas that might be corroded and visually assesses the level of corrosion, if applicable. They then attempt to determine what might attribute to its corrosion, such as exposure to long periods of wetness and joint leakage.
“We literally walk on and under the bridge, trying to view as many different areas as possible,”said Righman of Moatsville, W.Va.”Our visit to the New River Gorge bridge was a unique experience. We used a rigging truck to view several parts of the arch up close. That was a little intimidating at times, especially when you are 876 feet above ground, but it was definitely a lifetime opportunity that I’m glad I was able to be a part of.”
This coming winter and spring, the team is planning two visits to the southern part of the state to visit at least another 40 of the 100 weathering steel bridges.
“We literally have a map of West Virginia with a pushpin for each weathering steel bridge, labeling all the sights we want to visit. I’d like to visit some this winter but with the weather being so unpredictable, it’s hard to plan a definite trip,”Barth added.
After the evaluation is complete, the team will submit a final report of their findings to the DOH . It will be a general assessment of weathering steel performance in West Virginia. If necessary the team will continue to work with the DOH to create guidelines for future use of weathering steel.
“I think its great to be involved in this project where we have the potential to help the DOH , that at the same time provides a good learning experience,”Righman said.