Experimental asphalt being tested on Upper Michigan roads
Researchers at Michigan Tech are working with the Michigan Department of Environment, Great Lakes, and Energy and the Dickinson County Road Commission to test a new type of asphalt.
Zhanping You, Professor of Civil & Environmental Engineering at Michigan Tech helped to secure a $650,000 grant which was partially funded by the Michigan EGLE - formerly the DEQ.
It all starts at the asphalt plant, where they're using the exact same asphalt various aggregates, petroleum and heat. However, there’s one crucial difference. They also add powdered rubber tires. They crush used tires up into a fine powder and through it in the fire.
"We prepared the lab designs for example how much gravel, how much sand, how much rubber and how much asphalt,” Professor You explained. They’ve also determined precisely how thick each layer should be for maximized performance.
You and his students designed the new product called engineered crumb rubber. They also spent the past year or more running numerous tests in the lab. You says the new pavement performed well.
"We think if we are doing things right this type of material will last a long time without much cracking," You hypothesized.
Professor You, MDEQ and Dickinson County Road Commission will conduct an extended study on a portion of County Road 607 which has been paved with the new asphalt.
Lance Malburg, Engineer for the Dickinson County Road Commission is overseeing the project in the field. He’ll be watching for evidence of cracks and weakness on the roadway, especially once the real cold air sets in this winter.
"A couple of things we're looking at is off course the durability but we're also looking at noise control," Malburg declared.
Not only is this new asphalt more durable, meaning less potholes and cracking, but it’s also quieter which would reduce noise in high traffic areas.
"We'll also be looking at friction control which is stopping distance. Is it improved or not improved” Malburg proposed.
Professor You says the new pavement will only cost about $2 more per ton than conventional asphalt. In order to pave this roughly two mile stretch of CR-607 they've recycled 3940 used tires recycled.
Professor You says if this study goes well, the new asphalt could become the new standard, essentially eliminating the problem of what to do with all our old tires.