Peter Eady1, Didier Bodin1
- Australian Road Research Board, Vermont South, VICTORIA, Australia
The resistance of deformation of asphalt mixtures can be determined in a number of ways, including full-scale accelerated pavement testing as well as smaller-scale wheel-tracking laboratory tests. This paper describes a comparison of the performance of a Class 320 hot-mix dense graded asphalt mix using both accelerated pavement testing and laboratory tests.
The accelerated pavement testing examined the performance of a 150 mm thick asphalt layer, placed on top of a 300 mm thick cement treated crushed rock subbase. The material was subjected to over 100,000 cycles of a 50 kN load half-axle load. The pavement temperature was controlled via radiant heating, with a targeted mid-depth pavement temperature of 45°C.
Laboratory tests examined the deformation resistance of the same asphalt mix using wheel-tracking tests. Two sizes of test slabs were examined, the large size described in European standard EN12697-22 (500x180x100) as well as the size in the Austroads test method (300x300x75). Each size was tested at both 45°C (the same temperature as the accelerated pavement testing) and 60°C (the standard reference test conditions listed in Austroads test method AG:PT/T231).
The evaluation of the results examined the deformation performance of the three approaches, and the laboratory wheel-tracking tests to full-scale deformation performance were compared.
At a later stage, a similar process will be performed using foamed bitumen stabilised materials with varying percentages of recycled asphalt pavement.
Accelerated loading, wheel-tracking, laboratory tests
Peter Eady is a Senior Engineer at ARRB. His research has focused on projects dealing with improved understanding of the performance of foamed bitumen stabilised (FBS) pavements.
Dr Didier Bodin is a Principal Research Engineer at ARRB. His research has focused on the current Austroads projects dealing with rut-resistance characterisation, modelling and prediction of unbound granular materials response.