CHEMICAL & PHYSICAL PROPERTIES OF ASPHALT RUBBER MIXTURES--PHASE II PRODUCT SPECIFICATIONS AND TEST PROCEDURES

Asphalt-rubber was tested with conventional and non-conventional methods to begin development of testing methods for specification purposes and to find methods for studying the reaction between asphalt and reclaimed crumb rubber. A single asphalt-rubber formulation consisting of 75 percent AR-1000 asphalt and 25 percent crumb rubber from automobile tire treads (sized from No. 16 to No. 25) was used. Independent variables were three levels of reaction temperature (350, 375, and 400 F/177, 191, and 204 C), and three levels of reaction time (0.5, 1.0 and 2.0 hours). Dependent variables included ring and ball softening point, absolute viscosity by capillary viscometer at 140 F (60 C), ductility and force-ductility at 39.2 F (4 C), elastic rebound, and low temperature viscosity with the Schweyer rheometer at 39.2 F (4 C). Force-ductility was the only single test that detected the effect of reaction time and temperature. Variability of results was several times greater than is experienced for conventional asphalt cements and strongly suggests that conventional asphalt tests and criteria should not be used to specify this asphalt-rubber formulation. Recommendations are made for new tests, modifications of conventional tests and improved laboratory mixing and formulation techniques. An additional experiment is discussed that will use improved techniques to evaluate properties of other formulations, compare properties of field and laboratory produced mixtures, and to compare certain mixture properties with performance of experimental field test sections. (FHWA)

  • Corporate Authors:

    Engineers Testing Laboratories, Incorporated

    3737 East Broadway Road
    Phoenix, AZ  United States  85040

    Arizona Department of Transportation

    206 South 17th Avenue
    Phoenix, AZ  United States  85007

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • PAVLOVICH, R D
    • SHULER, T S
    • Rosner, J C
  • Publication Date: 1979-11

Media Info

  • Pagination: 145 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00311341
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA/AZ-79/121 Final Rpt.
  • Contract Numbers: 1-15(162) 77-12
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Jun 26 1980 12:00AM