Asphalt modifiers or recycling agents are frequently added to recycled asphalt mixtures to restore some of the properties of the binder which have been lost by weathering. It is recognized that the reclaiming agent and the material being salvaged must be thoroughly mixed to obtain satisfactory results. There is no standardized or widely accepted method for testing recycled mixtures to determine if the recycling agent has been widely dispersed. This paper concerns a study primarily aimed at the development of a test method for this purpose that could be conducted in thee field with a minimum of equipment and training; in effect, a test was sought to measure the efficiency of the mixing process for recycled mixtures. In the method developed, a small amount of dye chemical is mixed into the recycling agent. After the mixing of the pavement mixture, a briquet is molded, cut in half, and a treated fabric pressed against the face. This print shows where the dye chemical, and hence the recycling agent, is located in the mixture. A second print is made with a piece of dye print material saturated with a certain chemical to show the distribution of the asphalt binder. The overall mixing efficiency can be evaluated based on the distribution of the dye spots visually. Also, in the laboratory a system was devised using a digital densitometer equipped with a microcomputer to produce digitized plots of the dye print scans; then statistical methods were employed to test the normality of homogeneity of the dye distribution. Examples are shown. Ten field projects were conducted to evaluate the feasibility of the dye chemistry techniques. Based on these trials, the method was considered successful. In general, most of the dye prints obtained in the field showed that there was thorough mixing. (Author)

  • Supplemental Notes:
    • Paper from the Proceedings of the Association of Asphalt Paving Technologists Vol 52 pp 291-324, 1983.
  • Corporate Authors:

    Minnesota Department of Transportation

    Transportation Building, 395 John Ireland Boulevard
    St Paul, MN  United States  55155
  • Authors:
    • Anderson, D A
    • Dukatz, E L
    • Rosenberger, J L
  • Publication Date: 1985-4

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00395677
  • Record Type: Publication
  • Created Date: Feb 28 2002 12:00AM