PAVING ASPHALTS FOR FUTURE HIGHWAYS

IMPROVEMENT IS NEEDED IN ASPHALT SPECIFICATIONS FOR BETTER UNIFORMITY IN HANDLING CHARACTERISTICS OF ASPHALTS FROM VARIOUS SUPPLIERS DURING CONSTRUCTION. TWO APPROACHES TO PREPARATION OF IMPROVING PAVING ASPHALT SPECIFICATIONS ARE UNDER STUDY: (1) THE REPLACEMENT OF THE EXISTING PENETRATION TEST FOR GRADING ASPHALTS AND FOR DESCRIBING ASPHALT CONSISTENCY AND TEMPERATURE SUSCEPTIBILITY, WITH MORE FUNDAMENTAL VISCOSITY TECHNIQUES, AND (2) DESCRIPTION OF THE PROPERTIES OF ASPHALT DURING EACH PHASE OF ITS USE: IN BULK, STORAGE, MIXING WITH HOT AGGREGATE, COMPACTION AND AFTER LONG-TERM WEATHERING IN A PAVEMENT. WITH SIX NEW VISCOSITY TESTS, COUPLED WITH FOUR EXISTING TESTS, A NEW TYPE OF ASPHALT SPECIFICATIONS BASED ON VISCOSITY-GRADING WAS DEVELOPED. EXPERIENCE WITH VISCOSITY-GRADED ASPHALTS IS REVIEWED. SOME PLACES USE A SYSTEM WHICH USES VISCOSITY-GRADING BUT RETAINS PENETRATION. A SUMMARY IS PRESENTED OF VISCOSITY-GRADING SYSTEMS. THE CALIFORNIA DIVISION OF HIGHWAYS MATERIAL AND RESEARCH LABORATORY HAS PROPOSED A FUNCTIONAL APPROACH TO PREPARATION OF ASPHALT SPECIFICATIONS. IN THIS SYSTEM THE PROPERTIES OF THE ASPHALT IN THREE STAGES OF USE ARE CONSIDERED: DURING STORAGE, CONSTRUCTION, AND AFTER AGING IN THE PAVEMENT. THIS APPROACH IS REVIEWED WITH TEST METHODS TO IMPLEMENT THE FUNCTIONAL APPROACH. IT IS ANTICIPATED THAT THE NEW SYSTEMS WILL PROVIDE ASPHALTS OF GREATER UNIFORMITY DURING CONSTRUCTION, REGARDLESS OF THE TYPE OF ROLLING SPECIFIED. IMPROVED UNIFORMITY SHOULD RESULT IN MORE DENSE, TOUGHER PAVEMENTS.

  • Supplemental Notes:
    • pp 146-193, 19 FIG, 8 TAB, 1 APP
  • Corporate Authors:

    Sixth Paving Conference Proc

    ,    
  • Authors:
    • Kari, W J
  • Publication Date: 1968

Subject/Index Terms

Filing Info

  • Accession Number: 00211466
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 2 1970 12:00AM