ASPHALT VISCOSITY RELATED PROPERTIES OF IN-SERVICE PAVEMENTS IN PENNSYLVANIA

SIX VISCOSITY-GRADED ASPHALTS FROM DIFFERENT SOURCES WERE USED DURING 1964 IN THE CONSTRUCTION OF WEARING COURSE ON LEGISLATIVE ROUTE 219 IN CLINTON COUNTY, PENNSYLVANIA. THE ONLY SIGNIFICANT VARIABLE WAS THE ASPHALT TYPE. TESTS WERE CONDUCTED TO DETERMINE THE PROPERTIES OF THE ORIGINAL ASPHALTS AND THE ASPHALT RECOVERED FROM TIME TO TIME DURING THE LAST SEVEN YEARS. ONE ASPHALT PAVEMENT WAS BEGINNING TO SHOW SIGNS OF DISTRESS. AN AGEING INDEX BASED ON VISCOSITY AT 77 DEG F WAS FOUND TO CONFORM TO THE PAVEMENT PERFORMANCE RATING AND THUS SEEMS TO BE MORE USEFUL THAN OTHER INDICES OF COMPARATIVE AGEING AND LIFE EXPECTANCY OF THE TEST PAVEMENTS. SHEAR SUSCEPTIBILITY OF THE ASPHALT CEMENTS SEEMS TO BE ONE OF THE MAJOR FACTORS AFFECTING PAVEMENT PERFORMANCE. PRESENT VISCOSITY-GRADED SPECIFICATIONS SHOULD BE SUPPLEMENTED WITH A MAXIMUM PERMISSIBLE SHEAR SUSCEPTIBILITY VALUE AT 77 DEG F SO AS TO CONTROL THE DURABILITY OF THE ASPHALTS. THE MAXIMUM AMOUNT OF SHEAR SUSCEPTIBILITY THAT MAY DEVELOP IN A PAVING-GRADE ASPHALT PRIOR TO PAVEMENT FAILURE IS INDICATED FROM THE DATA OBTAINED. /AUTHOR/

  • Corporate Authors:

    Pennsylvania Department of Transportation

    Bureau of Materials, Testing and Research, 1118 State State
    Harrisburg, PA  United States  17112
  • Authors:
    • Kandhal, P S
  • Publication Date: 1972-2

Media Info

  • Pagination: 63 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00211758
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Dec 13 1972 12:00AM