U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-98-022
Date: May 1998
Oil and water don't mix-and nowhere is that more evident than in asphalt pavement. The asphalt binder, a petroleum-based product, "glues" the aggregates in a hot-mix asphalt pavement together. But water that seeps into the pavement can cause the asphalt to strip away from the aggregate. This type of moisture-induced damage, known as stripping, leaves the pavement extremely vulnerable to cracking, rutting, and other serious damage.
Bobbie Templeton, who has chaired the AASHTO Task Force on SHRP Implementation since 1995, has retired from the Texas Department of Transportation. At the April meeting of the Task Force, Templeton was recognized for his commitment, hard work, and leadership on behalf of the Task Force.
As you gain experience with a new technology, you learn how to customize or tweak it. "It's like mom's chocolate cake. She knew, from experience, to add a little salt to the original recipe," says Lee Smithson of the Iowa Department of Transportation (DOT), head of the Lead States team for innovative pavement maintenance materials. To share what they've learned from experience, the members of the Lead States team-Colorado, Idaho, Iowa, and Pennsylvania-are holding 1-day field demonstrations on innovative techniques for repairing common problems in asphalt and portland cement concrete pavements. The techniques had been evaluated under the Strategic Highway Research Program (SHRP).
Most highway engineers and contractors have gotten used to working with metric measurements, prompted in large part by the switch to metric specifications in Federal-aid construction contracts. Many of the rest of us, however, are still adjusting to the metric system (officially known as the International System of Units, or SI).
Highway agencies' decisions on when and where to conduct maintenance and rehabilitation work are only as good as the pavement performance models that help them make those decisions. Europe's PARIS (Performance Analysis of Road Infrastructure) project is developing accurate pavement performance models that will give highway agencies the tools to more efficiently plan and schedule maintenance and thereby keep roads in top condition. The project is using data collected from European test sections based on long-term pavement performance (LTPP) program guidelines.
Are you responsible for keeping steel-reinforced concrete structures in good shape? If so, you know the damage that can be caused by corrosion in the reinforcing steel. The costs to maintain, repair, and rehabilitate these concrete structures are overwhelming. And highway users must suffer through aggravating delays caused by detours, closed lanes, and other traffic restrictions in work zones.
State highway agencies plan to build 1,339 Superpave pavements in 1998, a nearly fourfold increase from the 350 Superpave projects built last year, according to a new survey by the Superpave Lead States team.