RELATIONSHIPS BETWEEN HARDENING OF ASPHALT CEMENTS AND TRANSVERSE CRACKING OF PAVEMENTS IN SASKATCHEWAN

TRANSVERSE CRACKING AND RELATED PAVEMENT PERFORMANCE ARE MAJOR PROBLEMS WITH FLEXIBLE PAVEMENTS IN SASKATCHEWAN, AN INVESTIGATION INTO CAUSES OF THESE PROBLEMS WAS BEGUN IN 1963 AND THE MOST SIGNIFICANT FINDING WAS A RELATIONSHIP BETWEEN ASPHALT SOURCE OR REFINERY AND THE AMOUNT OF TRANSVERSE CRACKING. THIS FINDING LED TO A NEW SPECIFICATION BASED ON TIGHTER VISCOSITY LIMITS FOR ASPHALT CEMENTS AND ALSO TO AN ASPHALT USAGE PROGRAM BASED ON VISCOSITY CRITERIA. TO DETERMINE IF ASPHALTS PRODUCED UNDER THE NEW SPECIFICATION STILL RESULTED IN SIGNIFICANTLY DIFFERENT TRANSVERSE CRACKING PATTERNS, A SECOND INVESTIGATION WAS BEGUN IN 1966. THIS PROGRAM CONSISTED OF MEASURING PENETRATION AND VISCOSITY CHANGES AND TEMPERATURE AND SHEAR SUSCEPTIBILITIES OF ASPHALT SAMPLED AT VARIOUS LOCATIONS IN THE TRANSITION FROM STORAGE TANK, TO 12 MONTHS SERVICE ON FIVE PROJECTS. THE RESULTS OF THIS INVESTIGATION ARE IN THIS REPORT. THE LARGEST CHANGES IN ASPHALT PROPERTIES OCCURRED DURING PUGMILLING AND DURING 12 MONTHS OF SERVICE RATHER THAN DURING ANY OTHER HANDLING PHASE. SOME ASPHALTS WERE AFFECTED MORE BY PUGMILLING THAN BY SERVICE AND OTHERS MORE BY SERVICE THAN BY PUGMILLING. THERE WAS NO DEFINITE RELATIONSHIP BETWEEN THE CHANGES IN ASPHALT PROPERTIES AND THE EXTENT OF TRANSVERSE CRACKING AFTER 12 MONTHS. HOWEVER, A VAGUE TREND BETWEEN CRACKING AND ENVIRONMENTAL CONDITIONS WAS BEGINNING TO SHOW. THE STUDY WILL CONTINUE FOR A FURTHER 12 MONTHS. /AUTHOR/

• Supplemental Notes:
  • Vol 38, pp 629-659, 6 FIG, 6 TAB, 1 REF, 1 APP
• Authors:
  • CULLEY, R W
  • Campen, W H
  • HINDERMANN, W L
  • Mcleod, N W
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1969-2

Subject/Index Terms

• TRT Terms: Asphalt cement; Concrete hardening; Flexible pavements; Hardness; Pavement performance; Pendulum tests; Pug mills; Shear strength; Temperature; Transverse cracking; Viscosity
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00211512
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM