Improved asphalt characterisation at Western Australian temperatures

At higher temperatures and lower traffic speeds, asphalt has lower modulus values. According to the current Austroads pavement structural design methodology, lower modulus values will result in increased pavement design thicknesses. However, empirical observations of pavements in service indicate that most of the asphalt fatigue damage accumulates at lower temperatures. This study aims to characterise the stiffness and fatigue performance of typical Western Australian asphalt mixes in order to evaluate opportunities for improving current asphalt mix and structural design practices. This will be achieved by the development of modulus master curves in accordance with Austroads test method AGPT/T274 (2016) and asphalt fatigue testing to develop mix-specific asphalt fatigue models. The project includes the investigation of four WA typical dense graded hot mix asphalt mixes, i.e. 20 mm with C320 binder; 14 mm with C320 binder; 20 mm with A35P (polymer modified) binder, and 14 mm with A35P (polymer modified) binder. The preliminary results indicate that for the 20 mm with C320 binder mix investigated, the asphalt modulus at high temperatures and low load frequencies is lower than the modulus proposed by the current Austroads design methodology. For the 14 mm with C320 binder mix investigated the asphalt modulus at high temperatures and low load frequencies is similar or higher than the modulus that would be assigned using the current design methodology. The preliminary fatigue test results indicate that the current Shell laboratory fatigue model adopted by Austroads predicted a longer fatigue life than has been measured in the laboratory. This has also been observed in other recent studies and suggests that the Shell laboratory fatigue model may not necessarily be representative of the laboratory performance of current Australian asphalt mixes.

• Record URL:
  http://arrbknowledge.com
• Authors:
  • Tseng, E
  • Latter, L
  • Jafari, H
  • Grobler, J
• Conference:
  • AAPA International Flexible Pavements Conference, 17th, 2017, Melbourne, Victoria, Australia
• Publication Date: 2017-8

Language

• English

Media Info

• Pagination: 13p
• Monograph Title: Roads of the future: embracing disruption: 17th AAPA International Flexible Pavements Conference, Melbourne, 13-16 August 2017

Subject/Index Terms

• TRT Terms: Axle loads; Bituminous materials; Bituminous pavements; Fatigue (Mechanics); Mix design; Modulus of deformation; Pavement performance; Pavements; Temperature; Test procedures
• Uncontrolled Terms: Materials technology (asphalt/bitumen/concrete); Pavement technology
• Geographic Terms: Australia; Western Australia
• ATRI Terms: Asphalt; Axle load; Material fatigue; Mix design; Modulus; Pavement performance; Temperature; Test method
• ITRD Terms: 5579: Fatigue (mater)
• Subject Areas: Highways; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01648334
• Record Type: Publication
• Source Agency: ARRB
• Files: ITRD, ATRI
• Created Date: Oct 10 2017 2:56PM