MORGANTOWN — After 18 months of failed road repairs in Wetzel County, Chesapeake Appalachia decided in August to try something new, green and home-grown. The natural gas producer installed Mechanical Concrete, a construction technology developed in Morgantown.
“We put it in our heaviest traveled area and it’s holding up well,” said Steven Mossor, construction superintendant for Chesapeake
Appalachia’s Central District of northern West Virginia and southwest Pennsylvania. Chesapeake’s problem was that its intensive Marcellus Shale operation was just too much for the agricultural community’s narrow, sometimes steep old roads. “The foundation or the subgrade of the road was soft — it was never constructed to handle the weight of the traffic that we were putting on it,” Mossor said. “You could actually see the road surface rolling as trucks went by.” Repairs inconvenienced the community and the company and, worse, they didn’t hold up. Civil engineer Samuel G. Bonasso heard about Chesapeake’s problems and called to say he had a solution.
Mechanical Concrete consists of cylinders — used tires with the sidewalls removed, lying on their sides — filled with aggregate, said Bonasso, president of Reinforced Aggregates Co. of Morgantown and inventor of the technology. It works where conventional technologies don’t because it manages forces differently.
“Most road construction methods depend on friction to hold the particles together,” Bonasso said. “In the Appalachians, we have lots of water. It gets in the base, the material slides sideways and that creates potholes and ruts.”
The cylinders of Mechanical Concrete resist that sliding. “When trucks drive on it or when water goes in it, there’s no place for it to go,” Bonasso said. He described tires as one of the most significant pieces of engineering of the 20th century, and he said cylinders made of tires are “virtually indestructible.”
“You’d have to have a truck that weighs five or six times what it weighs to break it,” he said. The West Virginia Division of Highways constructed a test road segment in 2006 in Doddridge County and, based on Mechanical Concrete’s performance, granted project approval about two years ago — about the same time Bonasso also received a patent.
The technology is easy to install. “All you do is put the cylinders down and fill them, and it’s ready to go,” Bonasso said. “You don’t have any compaction to do, and you can put any kind of top on it.” Mossor agreed. Chesapeake installed Mechanical Concrete on several sections of Brock Ridge Road, about 2.5 miles in total, and found it easier than the conventional roadwork.
“On a scale of one to 10, one being very difficult, this is probably a six or seven,” Mossor said — compared with a three or four for conventional technology. “It’s a lot easier and faster and it’s not as interruptive to the traffic flow,” he said. Because it’s easier, Bonasso said, it also has a cost advantage that he estimates at 25 to 50 percent.
Mossor backed that up, too.
“It’s considerably less expensive than the whole-depth foundation restoration,” he said. Mechanical Concrete is at its best in some of the most difficult conductions, according to Bonasso, including soft subgrades, as well as shoulders and edges where runoff can create problems. And it makes constructive use of an overwhelming waste stream — the U.S. generates more than 300 million waste tires a year.
Mossor believes Chesapeake could begin using the technology more widely. “Of course we’re just now getting into weather, and I’d like to see how it survives through the winter,” he said. But so far, he said, “It’s cost-effective, it’s fast and it gets the results we need.” REAGCO employs three and has granted construction project licenses to Laurita Inc. in northern West Virginia and GAL Construction in western Pennsylvania, as well as a manufacturing license to Tireland in Morgantown. A fourth license is pending.
Taken from the Daily Journal