Rubber is meeting road not in the usual sense of tires rolling on pavement but in rubber from scrap tires becoming part of road surfaces in some areas of Michigan.
Recent paving projects backed by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) in Bay and Clare counties are expanding Michigan’s use of rubber tire scrap in road resurfacing, keeping the materials out of landfills and shaping the highways of the future.
Elsewhere, plastic scrap has been integrated into asphalt as companies become more creative in finding end uses for plastic, rubber and other materials that have proven challenging to reuse in the past.
The projects in Bay and Clare counties also highlight a Michigan recycling milestone. As of 2022, the state’s major scrap tire processing businesses—about 10 in all—no longer send any regular scrap materials to landfills. Apart from small quantities too dirty or contaminated to be recycled, all the material is recovered and repurposed for use not only in road work but also as mulch and in rain gardens and septic fields; as weights for construction barrels and silage covers; in molded and extruded plastic products; as porous pavement for trails and pathways; and as tire-derived fuel.
“The scrap tire market in Michigan is in a transformation from managing scrap tires as a waste to creating economic value,” says Kirsten Clemens, scrap tire coordinator in EGLE’s Materials Management Division.
The repaving in Bay and Clare counties used material from about 59,500 tires on more than 5.5 miles of roadway. EGLE awarded Michigan Technological University a $396,000 grant for project design and testing. Each county’s road commission performed the paving work, resurfacing 4.5 miles of Seven Mile Road from E. Midland Road to E. Beaver Road in Bay County and 1.15 miles of W. Haskell Lake Road from Cook Avenue to Lake Station Avenue in Clare County. At both locations, the repaving was divided into sections to enable side-by-side comparison of the rubberized and conventional paving materials.
These two are far from the first such projects in Michigan. Last year alone, four Michigan counties completed rubberized local road projects using scrap from more than 30,000 tires. As far back as 2005 and 2006, Saginaw County rolled out a pair of 2-mile sections of rubberized asphalt. The Michigan Department of Transportation allows a portion of asphalt mixes to be recycled materials, but it is not required.
“We have about 20 years of projects, and we’ve got some really solid technology now,” Clemens says. “What we’re trying to do is expand the use by getting the material into the communities that need infrastructure solutions.”
The growing consensus is that rubber-modified paving is a winner for local roads. In 2019, EGLE helped fund a Michigan Tech project in Dickinson County to see how an asphalt-rubber mix would hold up to extreme Upper Peninsula weather. A study two years later found the pavement resists rutting during hot weather and cracking in the cold. Researchers will continue monitoring the project—which won a 2019 County Road Association of Michigan award—for 10 or more years.
Installation of rubber modified chip seal on Seven Mile Road in Bay County.