VISCOSITY GRADING FOR ASPHALT CEMENTS

TESTS FOR MEASURING THE CONSISTENCY OF PAVING-GRADE ASPHALTS IN THE RANGE OF 40 TO 325 F HAVE LED TO THE DEVELOPMENT OF SPECIFICATIONS FOR SPECIFYING GRADE REQUIREMENTS AT 140 F. THE PURPOSE OF THESE REQUIREMENTS IS TO PROVIDE UNIFORMITY IN ASPHALT VISCOSITY DURING PLACEMENT AND ROLLING OPERATIONS AND IN SERVICE RESISTANCE TO RUTTING. IT IS WELL KNOWN THAT PAVING-GRADE ASPHALTS CHANGE IN VISCOSITY DURING MIXING OPERATIONS. AND THAT ASPHALTS FROM DIFFERENT SOURCES CHANGE AT DIFFERENT RATES UNDER THE SAME CONDITIONS. RESULTS PRESENTED SHOW THAT A SERIES OF ASPHALTS HAVING ORIGINAL VISCOSITIES AT 140 F WITHIN A NARROW BAND HAD A VERY WIDE RANGE IN VISCOSITY AFTER A TEST THAT SIMULATES HOT-MIX HARDENING. STUDIES ON THE RELATION BETWEEN ASPHALT CONSISTENCY AND FIELD "SETTING" PROPERTIES OF THE PAVING MIXTURE ARE PRESENTED. THESE STUDIES INVOLVED THE USE OF 6 PAVING- GRADE ASPHALTS ON ONE CONTRACT. THE FIELD SETTING PROPERTIES SHOWED A GOOD CORRELATION WITH THE RECOVERED ASPHALT VISCOSITY AT 140 F. THE BEST CORRELATION COEFFICIENT WITH THE RECOVERED ASPHALT VISCOSITY IS THE VISCOSITY AT 140 F AFTER TESTS SIMULATING MIXING, NAMELY THESTANDARD THIN-FILM OVEN TEST OR THE ROLLING THIN-FILM OVEN TEST. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 26-29
  • Monograph Title: Symposium on viscosity grading of asphalts
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00211683
  • Record Type: Publication
  • ISBN: 0309019621
  • Files: TRIS, TRB
  • Created Date: Oct 3 1971 12:00AM