Investigating Binder Flushing of SP-2 Mixes

Mix bleeding, or binder flushing, is migration of the bitumen to the surface of the flexible pavement, with or without fines. Krishnan and Rao indicated that migration can happen by means of two mechanisms: first, by the diffusion of asphalt into the air voids when it is subjected to temperature exceeding its softening point and second by the movement of asphalt due to pressure gradient developed in asphalt. The development of this pressure gradient is due to the reduction of air voids under traffic loads. Both mechanisms can occur simultaneously and the contribution of each depends very much on the temperature-stiffness relationship of the binder, the air voids distribution in the mix and the traffic loads to which the pavement is subjected to. Literature lists mix segregation and binder contamination during the construction process as possible causes of binder flushing. The objective of this study is to analyze available data on early flushing sections of Superpave mixes in Nebraska and to have a better understanding of the possible causes.

  • Record URL:
  • Corporate Authors:

    University of Nebraska, Lincoln

    National Bridge Research Organization, College of Engineering and Technology
    Lincoln, NE  United States  68588-0531

    Nebraska Department of Roads

    1500 Highway 2, P.O. Box 94759
    Lincoln, NE  United States  68509
  • Authors:
    • Abdelrahman, Magdy A
  • Publication Date: 2005-9


  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 84p

Subject/Index Terms

Filing Info

  • Accession Number: 01153198
  • Record Type: Publication
  • Report/Paper Numbers: Research Project Number P559
  • Created Date: Mar 24 2010 1:13PM