The cold winter weather has left the roads peppered with potholes above the season’s average, but Bloomington-Normal has been making continual efforts to plug all the holes.
During this time of year potholes are normal occurrences for roadways, but due to the extreme weather and temperature shifts experienced by Bloomington-Normal, the potholes are more severe this year.
“The potholes are much worse this winter because of the number of freeze-thaw cycles and the extreme cold temperatures of this winter has driven the frost line to a much deeper depth than a typical winter,” Kevin Kothe, city engineer for the Bloomington Public Works Department, said.
“When the ground is frozen, water on the surface cannot soak into the earth.”
Potholes will continue to ensue until temperatures remain above freezing throughout the night.
A solution used by the Bloomington Public Works Department to combat the potholes is the use of cold patch. This is a material which binds and tightens the asphalt to cover the potholes.
Cold patch does not have to be heated up, due to such high temperatures so it can withstand colder temperatures.
A more permanent solution for the city when temperatures warm up and the frost line disappears would be hot patch. Hot patch is produced by the asphalt plants in the summer when you see roads being resurfaced.
The material needs to be heated up over 300 degrees and then provides the benefit of rolling into place and cools down to form a strong patch, Kothe said.
So far this season, the Bloomington Public Works Department has witnessed four sinkholes. The first occurred on 900 N. Lee St. on March 10. The second sinkhole transpired the following day on Locust Street.
A sinkhole is an area of ground with no natural external surface drainage and deals with sub-surface defects; potholes are surface level fractures in the asphalt.
Areas with karst terrain are susceptible to sinkholes, and about 10 percent of Illinois is underlain by karst according to the Illinois State Geological Survey.
However, the situation in Bloomington-Normal regarding sinkholes points to utility-related incidences that form underneath and eventually cause chunks of street to fall through, Kothe said.
Sinkholes can be more costly to repair because the city will have to cut open the street, dig down and try to find where the problem started.
“As far as potholes go, a person can e-mail us or call our pothole reporting number to let us know about it,” Kothe said. “We will have a crew go out and fill the hole as fast as we can.”