EVALUATION OF ASPHALT ABSORPTION BY MINERAL AGGREGATES

All mineral aggregates used in the hot mix asphalt (HMA) mixtures have some porosity and as such tend to absorb some amount of asphalt. Different test methods are used by the agencies to determine the amount of asphalt absorbed by the mineral aggregates. There is a need to develop a realistic and accurate standard test method for determining asphalt absorption, especially because of its time dependent nature, so that the void parameters (such as air void content, voids in the mineral aggregate, and voids filled with asphalt) of the compacted mix specimens can be determined uniformly and accurately by all agencies. Three mineral aggregates of different absorptive characteristics and two asphalt cements (AC-20 and AC-5 grades) from the Strategic Highway Research Program (SHRP) Materials Reference Library were used in this study. Although three primary absorption methods were used, a total of nine different conditionings/procedures were attempted. Based on the test results, it has been recommended that the Rice method be used for determining asphalt absorption after the HMA mix has been aged for 4 hours at 290 deg F. Also, the asphalt absorption has been found to follow a hyperbolic relationship with time and potentially reaches an ultimate (limiting) value. It is possible, based on this relationship, to predict asphalt absorption at any given time if the absorption values just after mixing and at other two aging times are known.

  • Record URL:
  • Corporate Authors:

    National Center for Asphalt Technology

    Auburn University, 277 Technology Parkway
    Auburn, AL  United States  36830
  • Authors:
    • Kandhal, P S
    • Khatri, M A
  • Publication Date: 1991

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 30 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00625359
  • Record Type: Publication
  • Report/Paper Numbers: NCAT Rept No. 91-4
  • Files: NTL, TRIS, ATRI
  • Created Date: Nov 19 1993 12:00AM