The Use of Simple Performance Tests in the Development of Rutting Resistant Criteria for Asphalt Mixes in Canada Stage 1

The use of Superpave mixes has become popular over the past several years in Canada. A joint research study was undertaken to develop rutting resistance criteria for Superpave and other asphalt mixes used in Canada. The study used the new Simple Performance Test (SPT) and an accelerated laboratory wheel rutting resistance test. The SPT is included in the American Association of State Highway and Transportation Officials (AASHTO) new Mechanistic-Empirical Pavement Design Guide (AASHTO 2002) as a means of asphalt mix characterization. Two surface course asphalt mixes and two binder course mixes from projects across Canada were selected for the study. These mixes span a wide range of applications from high traffic freeways to low volume municipal roads. This paper presents the findings from Stage 1 of the study that included dynamic modulus testing of all four mixes, extensive AASHTO 2002 analysis, and accelerated rutting resistance testing in the Hamburg Wheel Rut Tester. The paper emphasizes the necessity for careful calibration of the models used in the new mechanistic-empirical method of pavement design and the need for accelerated performance testing at the mix design stage.