U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-97-020
Date: February 1997
Reclaimed asphalt pavement (RAP) is an integral ingredient in most asphalt pavement construction and rehabilitation projects. Not only is RAP good for the environment, because it recycles materials rather than adding them to landfills, but it is also more economical.
Despite RAP's value, however, some highway agencies are hesitant to use it in Superpave pavements.
"Contractors want to use RAP, but some agencies have not allowed use of RAP in their Superpave mixes," says Dale Decker, vice president of research and technology at the National Asphalt Pavement Association. According to Decker, this stance is unfounded. "There's no reason for there to be any problem."
John Bukowski of the Federal Highway Administration (FHWA) agrees. "There's no prohibition against RAP in Superpave," says Bukowski. "All the regular Superpave criteria apply. It's an issue of what procedures you use to prepare the aggregate and binder for evaluation with the Superpave tests and for inclusion in Superpave mixes."
Bukowski explains that many highway agencies avoided using RAP in early Superpave projects to minimize the number of variables that could affect performance. Now that highway agencies are familiar with the Superpave system and using it on a regular basis, the situation is different. For example, the Florida Department of Transportation routinely uses RAP in its Superpave pavements.
Revised guidelines on the use of RAP in Superpave mixes are now being reviewed by the expert task groups on asphalt binders and mix design. Final guidelines should be available later this year.
For more information, contact John D'Angelo at FHWA (telephone: 202-366-0121; fax: 202-366-7909; email: firstname.lastname@example.org) or John Bukowski at FHWA (telephone: 202-366-1287; fax: 202-366-7909; email: email@example.com).