The Iowa Department of Transportation works with Iowa State University in search of projects that could help the future of roads. Their latest: looking into technology for heated pavement.
Halil Ceylan is the director of the Institute for Transportation’s program for sustainable pavement engineering and is a professor of civil, construction and environmental engineering at ISU. He is the principal investigator of the heated-pavement project, and said it started out as a class project.
“Given the harsh winter conditions we have here, we were thinking of a solution to provide safe traveling for the public,” Ceylan said.
They started doing lab tests and studies in August 2013, and received funding for the project from the Federal Aviation Administration to continue research.
That funding went toward the first test of the technology at the Des Moines International Airport. Ceylan said the research grabbed a lot of attention from others, and that’s how they brought the idea to the Iowa DOT. Now, the Iowa DOT and Iowa Highway Research Board are helping fund it.
“Winter can be tough in Iowa. If there’s something that can help increase mobility and public safety, we’re going to take a close look at it,” said Bob Younie, director of the office of maintenance at the Iowa DOT.
Younie said that what initially caught his eye about the project was the idea that the technology potentially could make the Iowa DOT’s rest areas safer. The state’s 38 rest areas see an average of 17 million people each year, he said, and that this project could help keep those sidewalk areas free of snow and ice.
The second aspect he believes could be a benefit are safer roads.
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“There are road geometries that are problems like tight curves. Maybe this is a solution, maybe not, but until we do some tests, and figure out what’s involved in making it happen, we don’t know enough,” Younie said.
The process of putting the electrically charged concrete in isn’t that much different from installing regular concrete, Ceylan said.
They start by pouring regular concrete and spreading it out like they would do for any normal road. Then they place 3 inches of the electrically conductive concrete on top. That is the only layer that heats up.
Ceylan said that the pavement temperature stays about 40 degrees when it is turned on, enough to melt ice and snow melted without getting too hot.
Ceylan also said that with any new technology, the life of it depends on economics. He said the electrically conductive concrete is 50 percent more expensive than regular concrete per square yard. He also said the cost to heat the pavement is about 2.8 cents per hour.
“We may hopefully reduce that as we optimize our system,” Ceylan said.
With winter finally wrapping up, Ceylan said that they were able to test the concrete in a lot of different conditions. They put in a total of 10 concrete slabs, and each of the slabs has different sizes and diameters of electrodes. This allows the researchers to see which one worked the best in energy efficiency. But Ceylan said here is more testing to do.
“Every winter is unique and different,” Ceylan said. “The more we test it, the better understanding we’ll have of the long-term system.”