PERMEANCE AS A MIX DESIGN CRITERION FOR ASPHALTIC CONCRETE PAVEMENTS

THE PAVEMENT OF THE BLAIR COUNTY TEST ROAD, TR 22, IS AN OVERLAY CONSISTING A 1 INCH BITUMINOUS WEARING COURSE OF VARYING GRADATIONS AND AGGREGATES. THE DESIGN AND PLACEMENT OF THIS EXPERIMENTAL PAVEMENT WAS BASED ON A DURABILITY STUDY WHICH IS INVESTIGATING RELATIONSHIPS BETWEEN ASPHALT HARDENING AND THE VOID CONTENT OF THE MIX. TWO DIFFERENT TYPES OF AGGREGATES, CAMBRIA SLAG AND WYANT CRUSHED CONGLOMERATE SAND, AND LIMESTONE FILLER WERE USED. TEN AGGREGATE GRADATIONS WERE PLACED USING VARIOUS COMPACTION PROCEDURES WHICH RESULTED IN THIRTY-SIX TEST SECTIONS. THIS 5.6 MILE ROAD HAS BEEN IN SERVICE FOR TWO YEARS. CHANGES IN AIR VOIDS, AIR AND WATER PERMEANCE, PENETRATION, ABSOLUTE VISCOSITY, AND ASPHALTENES HAVE BEEN NOTED. ALTHOUGH ONLY TWO YEARS HAVE PASSED SINCE CONSTRUCTION, LIMITED ANALYSES HAVE SHOWN THAT THE MIXTURES WITH THE HIGHER INITIAL VISCOSITY VALUES HARDENED MORE. THE RATE OF ASPHALT HARDENING IS INFLUENCED MARKEDLY BY THE LEVEL OF VOIDS. SKID NUMBERS AT 40 MPH (MEASURED ONE MONTH AFTER CONSTRUCTION) HAVE BEEN RELATED TO ASPHALT MIXTURE DESIGN PARAMETERS. SKID NUMBERS AT 40 MPH AND COEFFICIENT-SPEED GRADIENTS WERE ALSO RELATED TO PAVEMENT PERMEANCE. SKID VALUES OBTAINED AFTER TWO YEARS OF SERVICE HAVE BEEN RELATED TO AGGREGATE DISTRIBUTION, ACCESSIBLE VOIDS, AND PAVING DIRECTION. INCREASES IN COEFFICIENT-SPEED GRADIENTS HAVE BEEN ATTRIBUTED TO THE REDUCTION IN PERMEANCE. /FHWA/

  • Corporate Authors:

    Pennsylvania State University, University Park

    Department of Civil and Environmental Engineering, Sackett Building
    University Park, PA  United States  16802

    Pennsylvania Department of Transportation

    1215 Transportation and Safety Building
    Harrisburg, PA  United States  17120
  • Authors:
    • Gotolski, W H
    • ROBERTS, J M
    • Smith, R W
    • Ciesielski, C A
  • Publication Date: 1972-3

Media Info

  • Pagination: 55 p.
  • Serial:
    • Issue Number: 68-1

Subject/Index Terms

Filing Info

  • Accession Number: 00210483
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: State Stu
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: May 29 1973 12:00AM