Evaluation of Permanent Deformation of Asphalt Mixtures Using Loaded Wheel Tester

A majority of states in the U.S. had adopted the Superpave volumetric mix design system in the year 2000. However, this system does not have a standard mechanical test to evaluate the potential for permanent deformation (rutting) of the designed asphalt mix. National studies are underway to develop a fundamental test for this purpose but it will be a few years before that test is standardized and implemented. In the meantime, several states are considering loaded-wheel testers to proof-test the Superpave designed asphalt mixture. This paper describes the Georgia loaded wheel tester and its most recent version called Asphalt Pavement Analyzer (APA). Preliminary test results from the National Cooperative Highway Research Project 9-17 "Accelerated Laboratory Rutting Tests: Asphalt Pavement Analyzer" are given. This project has the objective of recommending a test protocol for the APA based on the correlation of laboratory rut depths to actual rut depths in controlled field experiments. Ref., 9 fig., 15 p