The chip-and-seal method of road repair, a blend of asphalt and gravel, is being planned for 96 miles of Bartholomew County rural roads this year.
That is substantially more than the 50 to 60 miles done annually over the past two years, as well as two-and-a-half times more miles than will receive a new blacktop this year, Bartholomew County Highway superintendent Dwight Smith said.
Roughly three times less expensive than new blacktop, chip-and-seal treatments usually repair cracks for at least five years, and help prevent potholes from developing during freeze and thaw periods, Smith said.
Every dollar spent on chip-and-seal can save from $6 to $14 in highway expenditures down the road, according to the Indiana Department of Transportation.
But while county commissioner Carl Lienhoop said “everybody wants overlay,” he also acknowledged it isn’t hard to see why.
Developed in 1935, the chip-and-seal treatment provides no structural strength, doesn’t repair all cracks, deteriorates faster than asphalt, becomes more slippery in the rain and makes more noise when driven upon, according to the National Transportation Research Board.
In the past, local residents have claimed loose gravel from chip-and-seal projects had cracked their windshields, as well as contributed to clogs in nearby drainage ditches, county highway engineer Danny Hollander said earlier this year.
There are also those who claim blotches from the mixture ends up on the body of their vehicles, commissioners chairman Larry Kleinhenz said.
Some years back, a few roads near Grandview Lake were used to experiment with a process called fog sealing, which involves placing a light layer of asphalt to help lock in the chip-and-seal gravel and reduce dust.
“But it doesn’t last very long,” Smith said. “Within a year, you don’t even notice it was there.”
Besides unsatisfactory results, fog sealing also turned out to be twice as expensive as traditional chip-and-seal, Kleinhenz said.
“It got to the point where we started wondering if we might be better off overlaying,” Kleinhenz said.
Another technique that involves placing a form of seal coat on the traditional treatments was attempted in rural subdivisions, but the excessive drying time involved in this process wasn’t acceptable, Smith said.
So until better solutions are developed that satisfy all parties, the county has no choice but to use chip-and-seal treatment as one way of addressing road deterioration, Kleinhenz said.
While the public notices the loose gravel and dust, they don’t see the tiny cracks capable of holding water that begin to appear in fresh asphalt within a relatively short time after it is laid down, he said.
That’s why some people mistakenly accuse the county of trying to convert a modern road back into gravel after chip-and-seal is used, Kleinhenz said.
What needs to be understood is that if the less expensive chip-and-seal treatment wasn’t immediately used to seal those tiny cracks after they appear, “there would be potholes everywhere,” Smith said.
