Full-Scale/Accelerated Pavement Testing: Current Status and Future Directions

Full-scale and accelerated pavement testing (FS/APT) began as early as 1909 with a test track in Detroit, as identified by Metcalf in NCHRP Synthesis of Highway Practice 235: Application of Full-Scale Accelerated Pavement Testing (1). Various other facilities have been developed and used worldwide to pursue this activity, defined in NCHRP Synthesis 235 as " the controlled application of a prototype wheel loading, at or above the appropriate legal load limit to a prototype or actual, layered, structural pavement system to determine pavement response and performance under a controlled, accelerated accumulation of damage in a compressed time period " (1). These facilities, as well as the testing performed by them, generally have had a fairly specific focus or scope. In addition, FS/APT facilities traditionally have been operational for limited periods. Results from FS/APT research activities created significant advances in pavement engineering practice. Historically, probably the most notable of these in terms of the effect on highway pavement engineering is the Road Test conducted by the Association of State Highway Officials (AASHO) in the late 1950s. For airfield pavements, tests at the U.S. Army Corps of Engineers (USACE) Waterways Experiment Station (WES) since 1940 essentially defined the state of engineering practice. During the 1970s and 1980s, worldwide FS/APT activities and results in other countries were significantly more productive than those in the United States, with important contributions being made by Australia, Denmark, South Africa, France, Britain, and the Netherlands, among others. Current efforts are marked by the renewed and resurgent interest in FS/APT programs worldwide since the mid-1980s. In the United States alone, major investments in FS/APT programs have been committed by FHWA, USACE (both at WES and at the Cold Regions Research and Engineering Laboratory [CRREL]), and the states of Minnesota, California, Texas, and Louisiana. In addition, the Federal Aviation Agency (FAA) is currently commissioning the largest APT machine in the world. The state of Florida and the National Center for Asphalt Technology (NCAT), in collaboration with the Alabama Department of Transportation, have both initiated major FS/APT efforts, which are likely to be the first new APT programs of the 21st century. It is primarily this surge of interest that motivated the formation by TRB of the A2B52 Task Force on FS/APT, which has the following objectives: