Why rubber roads are likely to become increasingly common in Michigan

LANSING — They won't be bouncy but Michigan's next roads are increasingly bound to be made with old tires, including a "road lasagna" technique already used in Ingham County.

State officials announced $2 million in grants last month for a variety of road projects using old tires.

Ingham County received a nearly $38,000 grant, enough to do about 750 feet of road built on top of a shredded tire base at Fitchburg and Parman roads near Leslie.

The projects tend to be small and on local roads. Most big projects use federal funding and tire rubber is considered experimental and generally can’t be used on roads that get federal funding, said Kelly Jones, managing director of Ingham County’s roads department.

Today's projects generally use rubber in the asphalt mix or rubber as a base and tend to be fairly small in scale, said M. Emin Kutay, an engineering professor at Michigan State University who works on rubber-modified roads.

"Typically our paving industry is slow to new things," he said. "They want to see it long-term first."

Based on his research, Kutay said experiments from the past decade or more are showing good techniques for producing mixes that can make quieter and longer lasting roads but may not be quite as good as other premium additives like polymers. When rubber-modified roads fail, it's usually a construction or mix problem and not the rubber itself, he said.

Keeping tires out of the landfill is the main reason to use rubber but there are other benefits to using their rubber for roads. Kutay said the surface can keep a dark black hue longer, and there's less noise and infirmities when the repurposed rubber is mixed properly.

Kirsten Clemens, scrap tire coordinator for Michigan's Department of Environment, Great Lakes, and Energy, said Michigan residents go through about 10 million tires a year.

"So there's a lot of tires," she said of the recycling possibilities.

Reusing tires has long been a goal and they are reused in a variety of ways: Some are burned for energy with special smoke scrubbers at landfills. Other tires get small-scale reuses like playground equipment or as planters.

There are potential hazards from scrap tire piles, she said, that lead to mosquito breeding grounds, visual nuisances and fire risks.

Tires also can't go into landfills as normal tires, Clemens added, because they could inflate with methane gas and rise to the surface, which causes problems for landfills.

Dave Ouwinga and his Porous Pave Inc. company, based in Grant, use truck tires to make porous surfaces like golf cart paths, driveways and rings around trees in cities.

Those metal grates around trees can be a liability for tripping and a maintenance time-killer for cities, Clemens said.

Like Ingham County, his company is one of several entities that were part of the $2 million EGLE grant announced in March. Ouwinga company's $60,000 will go toward a washing system and tests of porous pavement technology.

Ouwinga said he sometimes has to work around not having enough tires. They typically use semi tires, which don't have the nylon that consumer tires do.

"We've been having a little bit of a problem with truck tires," he said.

Ouwinga shared that his suppliers grind the tires into a small mix using 1/4-inch to 5/16-inch chunks held together with urethane glue. When they're low on tires, they either need to wait a few weeks to get more semi tires or mix in some consumer tires.

"There's a lot of demand," Ouwinga said. "You're seeing a number of new applications for tires."

Ouwinga has learned that football fields are moving over to using a smaller mix, crumb size, instead of sand underneath artificial turf.

"You'll see a black streak when a player drags their foot," he said.

EGLE's $2 million grant will go to a half dozen projects:

• $577,000 to Cobolt Holdings for equipment to process off-road tires that could be used for agricultural mats
• $60,000 for Porous Pave for a rock washing system and a project with Goodwill locations in West Michigan that will be providing plastic
• About $420,000 for a 2.3-mile rehabilitation of Dixie Highway in Saginaw County
• Nearly a half million dollars for two 16-mile pavement sealing projects, in Bay and Joseph counties
• About as much for a one mile stretch of paving on Midland Road in Bay County.
• $38,000 this year for Fitchburg Road in Ingham County

The Ingham County project, expected to be completed in 2024, would use tire shreds as a base and would use about 250,000 commercial tires.

She said a Belleview Road project, which used tires as a base over wetlands, "is performing well."

That project is called a "road lasagna" for the way it stacks materials, Clemens said. She said the road once had 30 inches of asphalt and was paved over whenever it sank, despite the extra weight only making it sink faster.

Contact Mike Ellis at mellis@lsj.com or 517-267-0415.