The University of Wisconsin-Madison’s Modified Asphalt Research Center is partnering with the transport departments at Wisconsin, Wisconsin, Idaho, Ohio, Colorado and Kansas to revise the durability standards that asphalt has to meet before it goes on roads.
Hussain Bahia, a professor of civil and environmental engineering, and his team at the Modified Asphalt Research Center, says this will streamline the process of making asphalt right where it starts, at the petroleum refineries of which asphalt is a byproduct.
“If I own the refinery and terminal and I have six different specifications to meet, I have to have six storage tanks,” he says. “It will cost me much more money to produce, and I will pass the costs on.”
And for states whose roads face many of the same problems, especially from harsh weather, that makes little sense.
The efficiencies could eventually spread beyond the states currently participating in this project. “There are a lot of northern climate states, and whatever we come up with, it’s important for us to be testing and thinking on the same page,” says Barry Paye, the materials lab supervisor at WisDOT, who earned his bachelor’s and master’s in civil and environmental engineering from the University of Wisconsin-Madison.
Even when multiple states form a purchasing group to streamline the administrative side of buying asphalt, those member states often will have different standards, Paye says. So Paye’s hope is that the states in the research project can attain consistent results and common specifications, then work as a group to save money and maintain more resilient roads.
“Our main problem is what’s called thermal cracks,” Bahia says. “If you drive around, you will see most of our roads in Madison have almost horizontal cracks from one edge of the road to the other, and spaced every 30 to 60 feet. This is an effect of the climate conditions we have. To create a specification to minimize that damage is really the starting point.”