OHIO VALLEY — Every year as winter transitions into spring, drivers begin to notice more and more potholes in the roadway. What has been called pothole season is in full swing, although many are not familiar with how potholes are formed.
While potholes are a naturally occurring part of paved roadways, the Gallia County works year round to fill them with cold mix and keep the roadways safe and in good repair. In 2017 the highway department spent $58,574.95 just on filling potholes. So far in 2018 they have used $19,425.10 on labor, equipment, and materials filling in potholes.
According to Gallia County Engineer Brett Boothe, potholes are the result of nature on road surfaces and not a result of aged asphalt or wearing out roadways.
“Fatigue cracking is typically where you see potholes, that’s typically in the driveway and in the wheel paths themselves as that is where the most fatigue is. Once you get the fatigue cracking, you get potholes that form,” said Boothe.
Boothe explained that potholes result in cracked or broken road surface that have been driven over substantially. The tires of vehicles works like a suction cup and dislodges chunks of asphalt in the roadway. The common cause of cracking in roadways in cause by vehicles driving and wearing on the road surface, but is increased rapidly from the freezing and thawing during the winter months, making late winter and early spring notorious for potholes.
The freezing and thawing damages the road surface when moisture expands during freezing, creating pressure and stressing the fracture.
Unfortunately, when potholes become most common asphalt plants are not open and running. Due to the nature of asphalt, which must remain warm until it is placed in the roadway, it becomes increasingly difficult to transport in the cold months.
The alternative to hot setting asphalt is cold mix, a special combination of stone, asphalt emulsion, and sometimes a small amount of kerosene to help preserve to mix in particularly cold weather. The county highway garage and other agencies used to have to purchase their cold mix from an outside business.
“What asphalt emulsion is an asphalt liquid plus water plus an emulsion, which is like a surfactant, which holds it there until it breaks down,” said Boothe. “The pugmill is like a conveyor belt that mixes eights and nines with the asphalt emulsion at a certain rate. So as the liquid is getting sprayed on the stone, there are paddles that are constantly moving around that mix the stone and liquid getting good coverage.”
Boothe is able to produce the cold mix on site with the pugmill at less than $60 per ton, and is able to sell it at cost to other townships and government agencies in Lawrence, Jackson, and Gallia Counties. The pugmill was in disuse for more than 10 years when Boothe decided to get it back in operation in 2010.
“I am proud to say we began in 2010 and continue to produce cold mix asphalt with our own employees and doing so cheaper than purchasing anywhere else even to this day,” said Boothe.
Reach Morgan McKinniss at 740-446-2342 ext 2108.