The purpose of this investigation was to study how changes in mix composition of bituminous mixtures affect tendency of separation. A first step was to develop a laboratory method for the measurement of separation tendency. This method separates the mix into three parts: fine, medium and coarse. As a measure of separation tendency the difference in asphalt content between fines and coarse content is used. The method, called the sh-method, has shown good repeatability. By using this method the influence of the following composition factors on separation tendency was investigated: (1) asphalt and filler content, (2) filler type, (3) aggregate particle size distribution, (4) addition of sand or gravel. It was concluded that the most important factors for separation tendency were filler content and filler quality. The influence of mix procedure and mixing time on separation tendency were also investigated. No clear effects were obtained. Finally the separation tendency for wearing course mixes from different asphalt plants with maximum aggregate size of 16 mm was investigated. The lowest value, measured as the difference in asphalt content between the fine part and the coarse part was 0.4% and the highest value 1.6%. Normally the mixes have values between 0.8 - 1.2%. (TRRL)

  • Corporate Authors:

    Svenska Byggnadsenreprenoerfoereningen

    P.O. Box 27029
    Stockholm 27,   Sweden 
  • Authors:
    • Hillgren, G
    • Sjoeblom, S
  • Publication Date: 1979


  • Swedish

Media Info

  • Features: Figures; Tables;
  • Pagination: 33 p.
  • Serial:
    • Issue Number: 23

Subject/Index Terms

Filing Info

  • Accession Number: 00307957
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Report/Paper Numbers: Monograph
  • Files: ITRD, TRIS
  • Created Date: Apr 22 1980 12:00AM