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Dickinson road project highlighted in state magazine

THE COVER STORY in the Winter 2019 edition of “Crossroads,” the quarterly journal of the County Road Association of Michigan, reviews a rubber-enhanced paving project completed in June on County Road 607 north of Iron Mountain.

IRON MOUNTAIN — A Dickinson County highway project designed to test the use of recycled tires in a colder climate is drawing statewide attention.

Crossroads, the quarterly journal of the County Road Association of Michigan, featured the 2019 County Road 607 paving work as the cover story for its winter edition.

“Dickinson has a culture that is open to exploring new ways to do things,” DCRC engineer Lance Malburg told the magazine.

The Daily News reported on the research in June, detailing an effort to pave three sections of County Road 607 north of Iron Mountain using varying combinations of conventional asphalt and recycled rubber.

The nearly 2-mile project is a partnership between the road commission; Michigan Technological University; Michigan Department of Environment, Great Lakes and Energy; and the Dickinson Trail Network. It involves using engineered crumb rubber combined with hot mix asphalt.

The experimental portion has three sections just over a half-mile long. Two segments are different percentages of “dry mix” crumb rubber and the third uses traditional asphalt control.

Dry mix rubber is crumbled and mixed into asphalt on site, rather than being melted into the asphalt before going to the job site.

Malburg told Crossroads he hopes the experimental sections will prove to be of higher quality and more economical than traditional asphalt.

Warmer southern states have been using engineered crumb rubber in asphalt since the early 2000s, but Dickinson now claims to be the northernmost agency in Michigan to try it.

“This particular project came about because it was something a professor at Michigan Tech had been researching and wanted to study in the real environment,” Malburg explained. “Dickinson put in $250,000, we received a $30,000 grant and Michigan Tech contributed $100,000. That’s relatively unheard of for the university.”

In the past, DCRC has partnered to test hot-in-place recycling, prefabricated chip seal and fiberized asphalt, Crossroads reported.

One research goal is to test the cold weather cracking resistance of the rubber-enhanced pavement. While that aspect remains to be evaluated, other initial tests were positive, Malburg said.

“Michigan Tech did early audio tests and the road is definitely quieter,” he said.

The project also includes a 2-foot paved shoulder for bicycling and pedestrians, part of the state’s Iron Belle Trail.