U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-98-025
Date: September 1998
Maryland, a member of the Superpave Lead States team, continues to move forward with implementation of the Superpave system. In 1996, the Maryland Department of Transportation (DOT) adopted the Superpave binder specification, and starting next year the DOT will specify Superpave mixes for all of its asphalt paving projects. The Maryland DOT's materials laboratories will thus no longer test conventional asphalt mixes for compliance with the State's old specifications. This change means cities such as Baltimore and other local governments will have a difficult time obtaining conventional binders and mixes, says Bob Sneddon of Maryland contractor P Flanigan & Sons, Inc., as most contractors will convert totally to the Superpave system.
After years of service, it's not unusual for portland cement concrete (PCC) bridge decks to become permeable, allowing water and chloride ions from salt to penetrate. This can eventually cause corrosion in the deck's reinforcing steel. Aging decks also frequently suffer from poor skid resistance, poor ride quality, inadequate drainage, and deteriorated sections.
Corrosion in steel-reinforced concrete is the primary cause of deterioration in bridges and other structures around the world. This deterioration exerts an enormous toll on highway agencies, who must find the resources to rehabilitate, replace, and maintain those structures. Highway users are also hard hit by the costs of delays caused by construction and work zone detours.
As reported previously in Focus, the Superpave system is becoming the mix design system of choice among State highway agencies. But what do paving contractors think about the new mix design system?
A major new initiative in the technology deployment area is the national technology deployment initiatives and partnerships (TDIP) program, which is aimed at hastening the adoption of innovative technologies. The program will focus on up to five deployment goals (to be designated by the Secretary of Transportation), and each goal will be designed to improve the efficiency, safety, reliability, service life, environmental protection, and sustainability of the Nation's surface transportation system.