TRANSVERSE CRACKING OF FLEXIBLE PAVEMENTS IN SASKATCHEWAN. PHASE 2. AGE-HARDENING OF SASKATCHEWAN ASPHALT CEMENTS

A 1963 TEST SECTION INDICATED THAT SASKATCHEWAN ASPHALT CEMENT PROVIDED A WIDE VARIETY OF PERFORMANCE EVEN THOUGH ALL HAD BEEN PRODUCED TO MEET THE SAME SPECIFICATIONS. SPECIFICATIONS WERE CHANGED TO NARROW THE RANGE OF PENETRATION AND VISCOSITY LEVELS SO THAT ASPHALTS WOULD BE COMPARABLE IN FUTURE STUDIES. IN 1966, AN INVESTIGATION WAS BEGUN TO MONITOR THE AGEHARDENING CHARACTERISTICS OF ASPHALTS PRODUCED TO MEET THE MODIFIED SPECIFICATIONS. ASPHALTS FROM FOUR SUPPLIERS WERE SAMPLED FROM FIVE TEST SECTIONS THROUGHOUT THE FIRST 36 MONTHS OF SERVICE. CHANGES IN PENETRATION AND VISCOSITY AND IN TEMPERATURE AND SHEAR SUSCEPTIBILITIES WERE COMPARED AGAINST CALCULATED STIFFNESS VALUES AND AGAINST THE NUMBER OF TRANSVERSE CRACKS. THE KEY CONCLUSION WAS THAT ALTHOUGH IN-SERVICE AGING INCREASED STIFFNESS, PUGMILLING ALONE PROVIDED THE ASPHALTS WITH SUFFICIENT STIFFNESS FOR TRANSVERSE CRACKING OF THE PAVEMENTS AT TYPICAL LOW IN-SERVICE TEMPERATURES.

  • Corporate Authors:

    Saskatchewan Dept Hwys, Regina /Canada

    ,    
  • Authors:
    • CULLEY, R W
  • Publication Date: 1972-5

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 50 p.
  • Serial:
    • Issue Number: tr16

Subject/Index Terms

Filing Info

  • Accession Number: 00212277
  • Record Type: Publication
  • Source Agency: Roads & Transportation Assoc /Canada
  • Report/Paper Numbers: Tech Rept
  • Files: TRIS, ATRI
  • Created Date: Feb 27 1974 12:00AM