Research of evaluation indexes for asphalt mixtures' wheel tracking test

It was found that air voids of the second period of wheel tracking test for asphalt mixtures didn't change with time through tests analysis. Thereout division point for first period and second period were determined. Evaluation indexes for wheel tracking tests contain rut depth, creep slope and percentage of rut depth. The index of creep slope, in element, was the slope of curve, and it couldn't determine the place of curve. The index of percentage of rut depth which contained compact de-formation and creep deformation determined the solo place. There was good correlation between creep slope and percentage of rut depth. Through comparison between laboratory wheel tracking tests and filed accelerated loaded facilities tests, same evaluations were made by creep slope and percentage of rut depth, related well to field performance. It was recommended that both creep slope and percentage of rut depth should be jointly evaluated wheel tracking tests, and that air voids of laboratory samples should be field initial air voids.