New Superpave Designed To Provide Longer Life For N.C. Roads
Posted July 29, 2002 5:19 a.m. EDT
RALEIGH, N.C. — Many Triangle drivers claim roads cost too much and take too much time and trouble to maintain. Officials with the state Department of Transportation are using science to try to save time and money for motorists.
Superpave -- Superior Performance Asphalt Pavement -- is being used to pave the new section of Interstate 540 and being used to repave Highway 70.
The concept started with a formula from the Federal Highway Administration. Lab technicians with the state Department of Transportation took the concept, cooked it and stress-tested it. Now they say Superpave meets the unique needs of North Carolina roads.
"This is basically a new asphalt design system. It's performance-based, it takes into account traffic volumes, traffic loading and the temperature -- both high temperates and low temperatures," state materials engineer Cecil Jones said.
"If you think of a bunch of marbles sitting on top of each other, the marbles just roll on top. If you put squares or cubicle-sized aggregates, they hold each other together, interlocking structure and they put a lot more resistance to surface loading," asphalt design engineer Chris Bacchi said.
Technicians blend in a polymer for heavily-traveled roads. Officials said the end result is fewer potholes, longer pavement life and savings to the taxpayers. Engineers said they like to get 10 years out of normal pavement, but the goal for Superpave is to be maintenance-free for 20 years.
This year, DOT crews are trying to use Superpave on half of all paving projects. Next year, they plan to use Superpave on all roads.