Researchers Kick Off Michigan’s Rubberized Asphalt Study

Researchers at Michigan Technological University (MTU) have initiated a study to look at roads with asphalt rubber mixes as part of a grant award from the Michigan Department of Environmental Quality (DEQ). MTU received two grants totaling $1.2 million under DEQ’s latest grant round.

One grant funds a study aimed at reducing emissions and odor. The other tests a new technology that could, among other things, lower energy costs and help road crews.

Tire Recycling Equipment

Some other states use rubberized asphalt, but Michigan wants to know more about how it works as seasons change, state officials said.

David Hand, chairman of the school’s civil and environmental engineering department, leads the study about emissions and odor. He said officials want to know if adding crumb rubber to asphalt will allow crews to meet Michigan’s current air quality emissions standards.

“They want to make sure that nothing is being added to the pavement that could harm the environment,” Hand said in a statement. “And they also want us to evaluate options for reducing the odors from asphalt plants.” With more than $336,000 from the state and matching funds from private sources, the team will test various mixtures to determine the best recipe for low emissions rubberized asphalt. They also will be looking at ways to neutralize odors that are typically caused by sulfur compounds.

The work will be conducted in the lab and at two Michigan asphalt plants, one in the Upper Peninsula and the other in lower Michigan.

The second study focuses on a technology developed by Professor Zhanping You. Using $1.7 million in funding, including more than $855,000 from the DEQ and additional private support, he will be refining and testing a way to make rubberized asphalt under cooler temperatures.

“Conventional hot-mix asphalt uses a lot of energy and releases a lot of fumes,” You said. “We use a foaming process at lower temperatures, that requires less energy and reduces greenhouse gas emissions.” The foam, made by injecting water into asphalt, yields a less viscous mixture so gravel can mix into it more easily. As it cools, You’s warm mix asphalt achieves a higher density than traditional asphalt, and it can be made when the weather turns chilly, extending the construction season.

“We’ve been doing research on both crumb rubber and warm mix asphalt since 2006 and this new project is a great opportunity to combine both technologies,” Professor You said.

© Scrap Tire News, November 2014