Quiet ride: Tech research used in road testing recycled rubber mixed with asphalt

HOUGHTON — If all goes as expected, two roads downstate will be quieter and hold up longer.

What the hundreds of thousands of drivers might not know is that they have Michigan Technological University to thank.

Tech’s research was put to work using recycled scrap rubber tires in construction of a road in Kalamazoo County in early August. Nearly 14,000 tires were used in the project, according to the Kalamazoo County Road Commission.

The group’s asphalt design was also used on a county road in Muskegon County, where emulsified rubber asphalt chip seal was compared to traditional asphalt.

Zhanping You, professor of transportation engineering at Tech, began researching uses for recycled scrap tires about 10 years ago. The tires are shredded into small pieces and used in combination with conventional asphalt.

“The polymer material we’re adding to asphalt can make the material have a better performance,” he said.

A hot rubber chip seal and thin overlay were used on the road, alternating with sections of conventional asphalt to compare their performance.

You said the new mix will reduce the deformation of the roads from rutting, and also reduce fatigue.

“We don’t have the exact results yet, but we think the life can extend at least 50 percent,” he said.

It also results in quieter roads. In preliminary testing in Kalamazoo, the rubberized road was about 5 to 6 decibels lower than with conventional asphalt, You said.

A team from Michigan Tech traveled downstate to watch the mix. The asphalt was manufactured downstate based off the designs from You’s lab.

You’s team also tested rubber asphalt on a section of road in Keweenaw County several years ago. Two sections were tested — one with hot mix, one with cold mix.

“The road is in pretty good condition, this many years past,” he said.

They have also tested mixes on a sidewalk on Michigan Technological University near the Alumni House.

The projects were funded partially through a Michigan Department of Environmental Quality Scrap Tire Development grant.

You said they plan to test on a road in Dix County next year. Testing could also be done in parking lots.

He said he’s also interested in working with the city of Houghton or Houghton County.

“We always like to do something locally, so everybody can see it,” he said.

You’s team has also researched repurposing other used materials, such as roof shingles or electronic waste materials, or plastic bags. They’ve also reprocessed materials such as waste wood or grass to an asphalt-like material for paving.

Hopefully, the tires’ potential use in roads will inspire an increase in their recycling, You said.

“We don’t have many large-scale recyclers here, so many tires have not been effectively re-used or recycled,” he said.