A team of researchers at the University of Kansas School of Engineering is working to solve a cracking problem that can arise from weatherproofing steel parts used for guardrails, light poles, sign structures and some bridges.
Researchers will seek to determine why cracks form at certain points during a process known as galvanization, which is when steel is dipped in molten zinc for a few minutes and then removed and cooled, leaving it with a shiny gray coating that creates a barrier from the elements and prevents the steel from rusting.
Caroline Bennett, associate professor of civil, environmental and architectural engineering, is the lead researcher on the project.
“Let’s say you have a galvanized light pole, and it’s connected to a base plate. For stability, the pole and the steel base plate must be welded together,” Bennett said. “That connection, known as a weldment, also gets galvanized. Sometimes, during that process, something will crack right at the point of attachment. We’re trying to figure out why and how to prevent it.”
The project is sponsored by the National Cooperative Highway Research Program through a $500,000, 30-month grant.
Bennett said the cracking is not a result of high winds or some other structural deficiency. It occurs periodically in the factory during the galvanization process. The cracking is typically detected at the factory before the materials are used in the field. Determining the cause could result in significant cost savings and increases in structural safety.
“Everyone throughout the process is confident they are following the proper steps, yet the cracking continues to be an issue,” Bennett said. “So in the end, no one really understands why it’s happening, and it costs a lot of money to continually replace these fractured weldments.”
KU will spend the first eight months of the project compiling written information on the cracking issue, then the next 22 months in the lab to conduct physical testing on materials.
“We know that in order for cracking to occur, there has to be a confluence of variables. That’s why we don’t see it all the time. Our job is to figure out which confluence of variables is the worst – and best – and draft specifications and guidelines for how to control it,” Bennett said.
This marks the first time KU has received a grant through the National Cooperative Highway Research Program. Teaming up with Bennett to assist on the project are fellow faculty members Jian Li and Stan Rolfe, also with the civil, environmental & architectural engineering department. Former faculty member Adolfo Matamoros, now a Distinguished Professor at the University of Texas-San Antonio, will also assist on the research.
KU is also joining with world-renowned experts in the galvanizing, metallurgy and welding industries: Lincoln Electric, GalvaScience and John Barsom Consulting.
“It’s an important project, in part just because we’ll be able to look at this with a holistic perspective,” Bennett said. “I think it will change industry practices with galvanized highway structures, and because of that, it’s really important work.”