When it comes to potholes, help is on the way, thanks to modern road construction technology. That’s the word from Nishantha Bandara, assistant professor of civil engineering at Lawrence Technological University.
The reason there are teeth-jarring, tire-blowing, alignment-destroying potholes is the simple fact that ice takes up more space than water. “All roads have cracks, so water seeps through those cracks and stays under the road,” Bandara said. “When water freezes, it expands. The volume of ice is greater than the same amount of water. So you see this heaving effect in the early part of winter when temperatures drop below freezing.”
Ice pushes up the road surface slightly, and then the process is reversed when there is a thaw – often with disastrous results.
“Even during the winter you get 40 degree weather, and the ice thaws to water – so then there’s a void under the pavement,” Bandara said. “And when a heavy vehicle passes by, there’s a collapse, and you have a pothole.”
Before joining the Lawrence Tech faculty in 2012, Bandara was supervising geotechnical engineer at the regional headquarters of the Michigan Department of Transportation (MDOT) in Southfield. He is continuing his research on the freeze-thaw cycle and soil stabilization in road construction. He is currently working on an MDOT-sponsored study of adding recycled materials to soil to further stabilize roads.
He predicts better days ahead for motorists because roads built in Michigan during the past few years use a new technique to allow water to seep through the road base and just keep going away from the pavement.
“The new construction you see MDOT and other agencies using has drainable bases,” Bandara said. “The idea is, when the water seeps through cracks, it’s not going to stay there. It drains through the drainable base and keeps going down. The idea is not to have any water under the pavement, so nothing can freeze. That is the solution.”
Keep an eye on the area of I-96/I-75 around the Ambassador Bridge in Detroit, among other places. This road reconstruction, part of the so-called Gateway Project, used this new technique – so check this road in the coming springs for potholes, to make sure it works.
“Hopefully, you will see fewer potholes,” Bandara said.
Motorists can only hope, although car repair shops may not be so crazy about the idea.