U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
This forum addresses current issues surrounding asphalt cement. Analysis of the physical, chemical, and performance properties of asphalt cement have become more complex in the past twenty-five years. This forum was established to meet quarterly to give owner agencies, suppliers, researchers, and others in the transportation community the opportunity to keep each other advised of new developments at the local, regional, and national levels.
Consider, for example, the use of rheometrics in analyzing asphalt cement. Rheometrics has been around for fifty years and is the study of flow characteristics of viscous materials. Since asphalt viscosity is a function of temperature, it behooves both users and producers to understand the rheology of asphalt as it is subjected to a broad range of temperatures in service.
Rheometric analysis is the basis of performance-graded asphalts in the Superpave method. However, implementation of Superpave is more a process than an event, requiring the development of standards and specifications which are workable for the users and producers.
FHWA supports six regional asphalt user-producer groups nationally through research grants, peer review, and policy guidance.