Tennessee tests eco-friendly asphalt on Williamson road

Published: Oct 11, 2007 1:00:00 AM
Media Contact: Kate Howard,

Source: Tennessean.com

Engineers to see how it fares in traffic, weather

TNDOT Workers spreading asphault

LoJac Enterprises workers Brian Phillips, left, and Josh Buck spread warm-mix asphalt on Old Hillsboro Road in Williamson County. The company and Tennessee Department of Transportation will test the cleaner, less harmful mix. (GEORGE WALKER IV / THE TENNESSEAN)

New asphalt being poured in one Middle Tennessee county may look like regular pavement, but state transportation officials say it's cleaner, less harmful to the environment and smells a whole lot better.

The Tennessee Department of Transportation has partnered with LoJac Enterprises to test a warm-mix asphalt on Old Hillsboro Road in Williamson County.

The warm mix releases fewer pollutants into the air and is easier on workers laying it in the summer because it's about 100 degrees cooler than traditional hot-mix asphalt.

While the new asphalt has been 28 percent more expensive in tests done by other states, TDOT is trying it at one location to see how it stands the test of time.

"Right now, it's up in the air, since it's new and experimental," said Brian Egan, assistant director of construction at TDOT. "We expect competitive bidding to drive the cost down."

 Thick layer of new asphault

LoJac workers pave Old Hillsboro Road with a warm mix. The asphalt, which is about 100 degrees cooler than traditional hot mix, is much easier on workers laying it. (GEORGE WALKER IV / THE TENNESSEAN)

LoJac decided to create the mix at two of its plants, in Murfreesboro and Franklin, and TDOT agreed to use the asphalt in the state's first test on a public road. LoJac is also selling the mix to private companies.

"With the lower temperatures, there are less emissions coming from our plant, less emissions on the road where we're working and less energy to make it," said asphalt sales manager Warren Garner.

Engineers with the National Center for Asphalt Technology at Auburn University in Alabama plan to sample the pavement and put it through a battery of tests to predict its performance in different weather and traffic scenarios.

A construction project can often be the site of increased ozone pollution given the combination of warmer weather, stop-and-go traffic and hot asphalt, said Laura Artates of the Clean Air Partnership of Middle Tennessee.