ASPHALT WORKABILITY

This paper reviews the research that has been done at the Heriot-Watt University on asphalt workability. The most recent phase of the research into asphalt workability has been to identify the influence of selected mix ingredient variations on the components of internal resistance to movement of hot rolled asphalt. The parallel rolling program in this phase of work used unchipped slabs. One outcome of this work is the definition of the potential variation in performance of a mix as a result of plant variations in metering mix ingredients. Among the research results obtained thus far are the following: (1) Increasing the filler bitumen ratio of an asphaltic mix has the effect of increasing the temperature sensitivity of the mix, the mix stiffens more rapidly with reducing temperature. The upper critical temperature is also increased with increasing filler bitumen ratio. A mix becomes less workable with increasing filler bitumen ratio. (2) Increasing the filler content of a mix reduces the components of resistance to internal movement for an asphaltic mix. The mix will become workable as filler is added, but it will also become more temperature sensitive. The upper critical temperature of a mix is increased with increasing filler content. (3) Increasing the bitumen content of a mix reduces the components of resistance to internal movement. The mix will become more workable as bitumen is added, but the temperature sensitivity will only be reduced if the filler content of the mix is reduced. The upper critical temperature is decreased with increasing bitumen content. (4) Increasing the pen grade of the bitumen reduces the components of resistance to internal movement. The mix will become more workable with increasing pen grade. The upper critical temperature is reduced with increasing pen grade. The temperature sensitivity of the mix will depend on its filler content.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/3831968
• Corporate Authors:

  D.R. Publications Limited

  Faversham House, 111 St James Road
  Croydon, Surrey CR9 2TH,   England 
• Authors:
  • KWEIR, K
  • FORDYCE, D
  • WHITEOAK, D
• Publication Date: 1990-1

Media Info

• Features: Figures; References;
• Pagination: 4 p.
• Serial:
  • Highways
  • Volume: 58
  • Issue Number: 1957
  • Publisher: Alad Limited
  • ISSN: 0142-6168
  • Serial URL: http://www.highways-mag.co.uk

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Bitumen; Fillers (Materials); Hot rolling; Internal forces; Materials selection; Performance; Research; Temperature; Workability
• Uncontrolled Terms: Hot rolled asphalt
• Subject Areas: Highways; Materials; Research;

Filing Info

• Accession Number: 00491304
• Record Type: Publication
• Report/Paper Numbers: Supplement
• Files: TRIS, ATRI
• Created Date: Feb 28 1990 12:00AM