The addition of hydrated lime to bituminous mixtures has been used as an aid for anti-stripping of asphalt-aggregate combinations. Previous work in Utah noted the hydrated lime supplement has the tendency to reduce the hardening rate of asphaltic binders and increase initial stability values. As a result, minimum immersion compression standards were developed, below which hydrated lime became a common bituminous mix supplement for improved mixture qualities. This study focused on a factorial laboratory design consisting of two aggregate sources (silaceous and calcareous), three viscosity graded asphalts (AC-10, AC-15 and AC-20), two lime sources and three concentrations of lime (0, 1/2 and 1 percent) to identify the interaction of asphalt-aggregate-and hydrated lime that yields reduced hardening of asphaltic binders and stronger bituminous mixtures. Results direct the cause for variance between separate combinations of asphalt and aggregate on immersion compression to the optimum asphalt content for different aggregate sources, and to a lesser degree the chemical components of the aggregate or asphalt. It is verified that the addition of hydrated lime to asphaltic concrete does increase stability and reduce the hardening rate of some asphalts. Recommendations are made to consider the use of one-half to one percent hydrated lime on the basis of RTFO viscosity in addition to wet-dry immersion compression ratio values. /FHWA/

  • Supplemental Notes:
    • Sponsored by and prepared in cooperation with the Federal Highway Administration, DOT.
  • Corporate Authors:

    Utah Department of Transportation

    Materials and Research Section, 757 West Second South
    Salt Lake City, UT  United States  84114
  • Authors:
    • Welch, B H
    • Wiley, M L
  • Publication Date: 1976-10

Media Info

  • Pagination: 70 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00165764
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: UDOT-MR-76-9 Final Rpt., FCP 44A1244
  • Contract Numbers: 500-923
  • Created Date: Mar 29 1978 12:00AM