Here's how much recyclable material is in Interstate 155 project and not in rivers, oceans

There's more than 11 tons of recycled plastic shopping bags and about 450 old tires in a new paving project on Interstate 155 along the Missouri Bootheel, a project of the Missouri Department of Transportation in partnership with the University of Missouri.

The 11.5 tons of plastic shopping bags in the I-155 project is equal to about 1.53 million bags, Buttlar said.

That's material that won't go into landfills, rivers, oceans or wildlife.

The practice had been used previously in 2021, when workers resurfaced a two-mile section of Stadium Boulevard from U.S. Highway 63 to College Avenue in Columbia.

That project used 10 tons of recycled plastic and proved how it can work, said Bill Buttlar, director of the Mizzou Asphalt Pavement and Innovation Lab.

"It's holding up quite well," Butlar said of the Stadium project. "It was a relatively thin resurfacing, just an inch-and-a-half."

There was some blistering where the layer was even thinner, but nothing too unusual, Buttlar said.

"It's performing well," he said. "We haven't seen any early major problems."

Driving along the section of Stadium, it's impossible to discern any difference from pavement without recycled pavement.

The I-155 project covers six miles on a single lane of traffic.

"For high-traffic roads such as interstates, MoDot has not allowed recycled materials to be used," Buttlar said.

The agency allowed it now because of MU's previous research, he said.

"We're really trying to stretch the research into practice," he said.

The project uses types of plastic not used before on previous projects, Buttlar said.

The dry process the MU lab uses allows researchers to to easily add recyclables into the asphalt mixture before it's applied to a road surface.

The research has been useful and productive, said Punya Rath, assistant research professor in the MU department of civil and environmental engineering.

Small-scale testing came before big projects, Rath said.

"I definitely feel it's a good solution," he said.

Widening Interstate 70 to three lanes in each direction could provide another opportunity to use recyclable plastic and rubber, Buttlar said. There are preliminary talks about doing that.

MoDot is making using recyclables a part of its bid process on projects, he said.

"I think MoDot is becoming a national leader in using the recycled materials," Buttlar said. "Contractors will compete for the work. We've come up with methods they can win on cost."

The projects are making a dent in the supply of waste plastic, he said.

"We know there's plenty of supply," he said "We generate so much waste, there's a plentiful supply for roads."

Roger McKinney is the Tribune's education reporter. You can reach him at rmckinney@columbiatribune.com or 573-815-1719. He's on Twitter at @rmckinney9.

This article originally appeared on Columbia Daily Tribune: Widening Interstate 70 may be another use of waste plastic supply