MODIFICATION OF ASPHALT CEMENTS FOR IMPROVEMENT OF WEAR RESISTANCE OF PAVEMENT SURFACES

THE OBJECTIVE WAS TO EXPLORE THE FEASIBILITY OF REINFORCING ASPHALT CEMENTS BY FILLERS AND POLYMERS. THE EFFECTS OF CARBON BLACKS VARYING IN PH, PARTICLE SIZE, AND STRUCTURE WERE EVALUATED. GROUND LIMESTONE SERVED AS A CONTROL. IT WAS CONCLUDED THAT CONVENTIONAL FILLERS SUCH AS LIMESTONE DUST DO NOT CONSTITUTE FILLERS FOR ASPHALT CEMENTS, BUT ARE PART OF THE AGGREGATE, AND THAT ONLY HYDROPHOBIC MATERIALS OF A PARTICLE SIZE LESS THAN 5 MICRONS CAN FUNCTION AS FILLERS FOR THE ASPHALT CEMENT. OF THE FILLERS INVESTIGATED, FINE PARTICLE SIZE, HIGH STRUCTURE BLACKS WERE FOUND TO BE MOST EFFECTIVE. THE CONSTANT RATE EXTENSION TEST SHOWED THAT THE TENSILE STRENGTH OF ASPHALT CEMENT IS INCREASED BY CARBON BLACK MODIFICATION. A SIGNIFICANT INCREASE IN RESISTANCE TO RUPTURE WAS ACHIEVED BY MODIFICATION OF ASPHALT CEMENTS WITH ELASTOMERS AND ELASTOMERS PLUS BLACK. STRESS-STRAIN PROPERTIES DEFINED BY THE LOAD-DEFORMATION CURVE WERE USED TO DEPICT THE FINDINGS. THE PELLET ABRASION TEST ON OTTAWA SAND MIXTURES, CONSIDERED A TOUGHNESS TEST IF RUN OVER A RANGE OF TEMPERATURES, SHOWED GREAT INCREASE IN TOUGHNESS THROUGH ADDITION OF POLYMERS. THE BEST ABRASION RESISTANCE AT LOW TEMPERATURES WAS OBTAINED BY THE ADDITION OF BOTH ELASTOMERS AND BLACK. TWO ADDITIONAL TEST PROCEDURES USED TO MEASURE THE EFFECT OF TIRE STUDS ON MASTICS AND ASPHALT CONCRETE DID NOT PROVIDE USEFUL QUANTITATIVE DATA. A CONTINUATION OF THE STUDY, TO ARRIVE AT PRACTICAL SPECIFICATIONS FOR EXTRA WEAR RESISTANT SURFACES, IS RECOMMENDED. /FHWA/

  • Availability:
  • Corporate Authors:

    Materials Research and Development, Incorporated

    2730 Adeline Street
    Oakland, CA  USA  94607
  • Authors:
    • Rostler, F S
    • White, R M
    • Cass, P J
  • Publication Date: 1972-3

Media Info

  • Pagination: 165 p.
  • Serial:
    • Issue Number: 224

Subject/Index Terms

Filing Info

  • Accession Number: 00210479
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • ISBN: #224
  • Report/Paper Numbers: FHWA-RD-72- 24 Final Rpt., FCP 34A1-063
  • Contract Numbers: FH-11-7732
  • Files: TRIS, USDOT
  • Created Date: Apr 23 1973 12:00AM