Increasing the use of RAP in Western Australia

Reclaimed Asphalt Pavement (RAP) is material recovered from a surface usually by cold milling. RAP contains valuable bituminous binders that along with the accompanying aggregates, can be processed and added to new asphalt for beneficial reuse. RAP is typically comprised of older asphalt where the binder has aged, and the viscosity has increased to the point where the RAP binder has a much higher viscosity than that of the virgin binder used in new asphalt. If blended inappropriately or the viscosity of the RAP binder varies significantly this can impact the durability properties of the asphalt adversely. Austroads has completed a multi-year project to achieve improved outcomes when higher RAP contents are used in new asphalt. The process measures the binder viscosity of both the RAP binder and virgin binder to determine the blended binder viscosity for manufacture of asphalt with a high RAP content. The design inputs, such as RAP quantity and virgin binder viscosity can be varied to achieve a target viscosity for the blended bitumen. Main Roads Western Australia (MRWA) wants an increased use of RAP in asphalt and to achieve a reliable end product, plans to implement the Austroads process. This paper documents the pathway to implementation, including determining variability of the properties of RAP stockpiles over a 12-month period and determining historic local production of RAP to develop a position on a sustainable level of RAP usage. The outcome will be a MRWA Engineering Road Note detailing the design of asphalt mixes containing higher levels of RAP including a new approach to managing the viscosity of virgin bitumen being added to the mixture. Additionally, asphalt and supporting specifications will be updated.

• Record URL:
  http://arrbknowledge.com
• Authors:
  • van Aswegen, E
  • Latter, L
  • HALLIGAN, S
  • Griffin, J
• Conference:
  • AAPA International Flexible Pavements Conference, 18th, 2019, Sydney, New South Wales, Australia
• Publication Date: 2019-8

Language

• English

Media Info

• Pagination: 12p
• Monograph Title: Our everlasting roads – enabling future mobility: 18th AAPA International Flexible Pavements Conference and Exhibition, 18-21 August 2019, Sydney

Subject/Index Terms

• TRT Terms: Asphalt pavements; Binders; Bituminous pavements; Properties of materials; Viscosity; Waste products (Materials)
• Uncontrolled Terms: Pavement technology
• Geographic Terms: Western Australia
• ATRI Terms: Binder; Bituminous pavement; Material properties; Reclaimed asphalt pavement; Variability; Viscosity
• Subject Areas: Materials;

Filing Info

• Accession Number: 01718301
• Record Type: Publication
• Source Agency: ARRB Group Limited
• Files: ITRD, ATRI
• Created Date: Sep 26 2019 12:33PM