Mitch Emmons (emmonmb@mail.auburn.edu)

AU'S NCAT DEVELOPING PERFORMANCE TESTS FOR ASPHALT ROADS

AUBURN -- The National Center for Asphalt Technology at Auburn University is heading a three-year, $500,000 national study to develop performance tests for hot mix asphalt which covers more than 94 percent of the nation's highways.

Departments of transportation in all 50 states are supporting the AU project which in addition to developing new testing technology, also is evaluating existing test methods, said Prithvi Kandhal, associate director of the NCAT and principal investig ator on the project.

"Many current aggregate tests used in the U.S. and other countries were developed empirically based on general experience without, necessarily, any relationship to the performance of the specific final product," Kandhal said. "Some tests were develop ed more than 70 years ago and are still in use in spite of improved materials testing technology and research tools available today."

Hot mix asphalt consists of coarse aggregate (stone) particles and asphalt to bind the aggregate together, Kandhal explained.

"It must be tough and resistant to abrasion," he said. "Otherwise, it will break down under traffic and changes in weather conditions."

The mix also must maintain a sufficient, non-slippery surface, Kandhal added.

The project is administered by the Transportation Research Board of the National Academy of Sciences. Test methods recommended at the conclusion are likely to be adopted nationally and internationally, according to Kandhal.

CONTACT: Kandhal, 844-6242.