TEMPERATURE-SUSCEPTIBILITY CONTROL IN ASPHALT-CEMENT SPECIFICATIONS

THE INTRODUCTION OF SOME WAXY ASPHALT CEMENTS INTO ONTARIO IN THE EARLY 1950'S CAUSED SOME SERIOUS CONSTRUCTION PROBLEMS WHERE THESE PRODUCTS WERE USED. THE PROBLEM WAS ONE OF TEMPERATURE SUSCEPTIBILITY WHERE THE ASPHALT CEMENTS BECAME VERY THIN AT HIGH TEMPERATURES. THIS CAUSED PROBLEMS WITH DRYING AND IN LAYING AND COMPACTING THE MIX. A SOLUTION TO THE PROBLEM HAS BEEN OBTAINED BY CONTROLLING THE TEMPERATURE SUSCEPTIBILITY WITH A 2-POINT CONSISTENCY SPECIFICATION. THIS CONSISTS OF A MINIMUM VISCOSITY SPECIFICATION AT 275 F IN ADDITION TO THE NORMAL PENETRATION AT 77 F. THE MINIMUM SPECIFICATIONS ARE ABOVE THOSE RECOMMENDED BY THE ASPHALT INSTITUTE. RELATIONSHIPS HAVE BEEN DETERMINED BETWEEN PENETRATION AT 77 F AND VISCOSITIES AT 77, 140, AND 275 F FOR ASPHALT CEMENTS CURRENTLY SUPPLIED IN ONTARIO. A NEW CRITERION FOR LOW-TEMPERATURE PERFORMANCE, CRITICAL TEMPERATURE, IS INTRODUCED. THIS IS AN INDICATION OF THE LOW-TEMPERATURE FLOW PROPERTIES OF THE ASPHALT MIX. A METHOD IS ALSO SUGGESTED FOR THE SELECTION OF A SUITABLE ASPHALT-CEMENT GRADE FOR VARIOUS LOW TEMPERATURE ENVIRONMENTS BY USING STIFFNESS MODULUS. /AUTHOR

Media Info

  • Media Type: Print
  • Features: Appendices; Figures; Tables;
  • Pagination: pp 30-45
  • Monograph Title: Symposium on viscosity grading of asphalts
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00211684
  • Record Type: Publication
  • ISBN: 0309019621
  • Files: TRIS, TRB
  • Created Date: Oct 3 1971 12:00AM