Paved divots, asphalt crevasses, chuck holes, nature’s speed bumps. Call them what you want, “frost heaves,” are the seasonal bane of every Maine driver.
An undeniable, if unwelcome sign of spring, frost heaves — an upward swelling of soil occurring where there are seasonal freezing and thaw cycles — create everything from minor annoyances to major hazards on roads from Kittery to Fort Kent.
“You need three things to create a frost heave,” said Clifton Curtis, assistant highway maintenance engineer with the Maine Department of Transportation. “You need frost-susceptible soil like clay, moisture, and freezing temperatures, [and] Maine has all three so I guess we are a winner.”
While drivers and road maintenance crews only see the rises and falls of the frost heaves on the road, Curtis said there is a lot going on under the surface to create the road condition.
“Water gets into what is under the road and when that water freezes it expands [and] as the winter goes on more water is drawn in. It freezes and the soil rises, pushing up the road,” Curtis said. “When the soil starts to thaw in the spring, some areas will thaw faster, causing the soil to retract and that part of the road will drop, creating what we call ‘frost heaves.’”
To avoid frost heaves, according to Dr. Melissa Landon, associate professor of civil and environmental engineering at the University of Maine, the best bet is to build roads over soil that does not trap water which can then freeze in the winter.
“In areas where sand is present like on [Route 9] the Airline where part of the road is built on a glacial esker, which is basically a big pile of sand, you often won’t see frost heaves,” Landon said. “You are mostly going to see them where the soil beneath the road is the type that traps and holds moisture, like clay.”
The only solution to mitigating or eliminating the frost heaves, according to Curtis, are removing the frost-susceptible soil, removing the water or keeping the road from freezing.
The County is pleased to feature content from our sister company, Bangor Daily News. To read the rest of “Spring in Maine means frost heaves in the roads,” an article by contributing Bangor Daily News staff writer Julia Bayly, please follow this link to the BDN online.
