RESEARCH REPORT IR-9: A STUDY OF PHYSICAL FACTORS AFFECTING THE DURABILITY OF ASPHALTIC PAVEMENETS

THE FOLLOWING FACTORS AFFECTING IN-SERVICE ASPHALT HARDENING AND PAVEMENT DURABILITY ARE STUDIED: TRAFFIC DENSITY, MIXTURE COMPOSITION, AGGREGATE TYPE AND GRADATION, PAVEMENT DENSITY AND AIR VOIDS, AND ASPHALT CONSISTENCY IN CHEMICAL COMPOSITION AS DETERMINED BY THE ROSTLER METHOD OF ANALYSIS. PAVEMENT DURABILITY IS EVALUATED BY PERIODIC INSPECTION. ASPHALT HARDENING IS EVALUATED BY CHANGES IN COMPOSITION, PENETRATION, VISCOSITY AND DUCTILITY. THE WEARING COURSES IN THE FOLLOWING THREE PAVEMENT GROUPS ARE BEING STUDIED; (1) SWEEP PAVEMENTS CONSTRUCTED IN 1964-1965 WITH SIX DIFFERENT ASPHALTS AND A SINGLE AGGREGATE, (2) SIX PAVEMENTS CONSTRUCTED IN 1963 WITH 70/85 GRADE ASPHALTS AND THE FOLLOWING THREE AGGREGATE TYPES: GRAVEL AND SAND, LIMESTONE AND SAND, AND LIMESTONE, SAND, AND FLYASH, (3) FOUR PAVEMENTS LAID IN 1961-62 CONSTRUCTED WITH 70/85 PENETRATION GRADE ASPHALTS AND ONE WITH AN 85/100 PENETRATION GRADE ASPHALT USING SLAG AGGREGATE AND TWO PAVEMENTS AND ALL LIMESTONE AGGREGATE IN THE REMAINING TWO PAVEMENTS. TRENDS NOTED ARE THAT PAVEMENT VOIDS ARE DECREASING, ASPHALTENES INCREASING AND THE ASPHALTS GENERALLY HARDENING. TENTATIVE CONCLUSIONS GIVEN ARE: (1) HIGH AIR VOIDS ARE A MAJOR FACTOR CAUSING HARDENING OF ASPHALT INSERVICE, (2) HARDENING OF THE ASPHALTS IN THE PAVEMENTS OCCURS ONLY DURING THE WARMER MONTHS OF THE YEAR, AND (3) THE ROSTLER CHEMICAL PARAMETER IS NOT A USEFUL PREDICTOR OF ASPHALT HARDENING IN SERVICE.

  • Supplemental Notes:
    • Hpr-1(5), 040
  • Corporate Authors:

    Pennsylvania State University, University Park

    Pennsylvania Transportation Institute, Transportation Research Building
    University Park, PA  United States  16802

    Pennsylvania Department of Highways

    400 North Street
    Harrisburg, PA  United States  17120-0095

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Gotolski, W H
    • Smith, R W
    • ROBERTS, J M
  • Publication Date: 1968-9

Subject/Index Terms

Filing Info

  • Accession Number: 00206350
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Mar 18 2000 12:00AM