Mechanical Concrete is Another Tool for Chesapeake
State Journal
22 December 2010
By Pam Kasey
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 superintendent 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.