Gyratory compaction was adopted for asphalt mix design in Australia at about the same time as it was in the United States, and two Australian based gyratory compaction devices were developed. To more fully understand the compaction process, tests were carried using out oil/aggregate mixtures instead of bitumen/aggregate mixtures. This was done by choosing an oil of such a viscosity that the compaction curves of aggregate/oil mixtures compacted at room temperature were identical to those for the corresponding aggregate/bitumen mixtures compacted at 150 degrees celcius. Tests using oil/aggregate mixtures showed a relationship between 1 cycle voids content and resistance to rutting, as measured using a wheel tracker, for a very wide range of mixes. This suggests that 1 cycle, or possibly 10 cycle, voids may be a useful indicator of rutting resistance in the design of conventional, bitumen-bound asphalt mixes. Testing using a mix consisting of smooth, rounded particles showed that, while it met refusal density requirements, it was extremely prone to rutting. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E208431.
Samenvatting