AN INVESTIGATION ON THE PERMEABILITY OF ASPHALT MIXES

A PROCEDURE WAS DEVELOPED FOR MEASURING THE AIR PERMEABILITY OF VARIOUS SPECIMENS OF COMPACTED ASPHALT. A METHOD OF DETECTING ANY ACCIDENTAL CHANGES IN THE COMPOSITION OF A MIXTURE PRODUCED BY AN ASPHALT PLANT, SOON AFTER MANUFACTURE OF THE MATERIAL, USING THE AIR PERMEABILITY APPARATUS IS ALSO SUGGESTED. SPECIMENS OF ASPHALTIC CONCRETE CONFORMING TO THE REQUIREMENTS OF THE ONTARIO DEPARTMENT OF HIGHWAYS FOR SURFACE COURSE MIXTURES, WERE PREPARED BY THE MARSHALL METHOD AND TESTED IN THE AIR PERMEABILITY APPARATUS. THE VOID CONTENT WAS MEASURED AND RELATIONSHIPS ESTABLISHED BETWEEN PERMEABILITY AND VOID CONTENT. A MARKED DECREASE IN PERMEABILITY OCCURED BELOW A VOID CONTENT OF ABOUT 5 PERCENT FOR ALL MIXTURES TESTED. THE EFFECTS OF COMPACTIVE EFFORT, ASPHALT CONTENT AND AGGREGATE GRADATION ON PERMEABILITY AND VOID CONTENT WERE ALSO INVESTIGATED. SEVERAL DRY AGGREGATE BLENDS WERE TESTED IN THE AIR PERMEABILITY APPARATUS AND THE EXPERIMENTAL PERMEABILITIES OBTAINED WERE COMPARED WITH VALUES CALCULATED BY MEANS OF THE KOZENY EQUATION, USING THE SPECIFIC SURFACE CALCULATED FROM THE GRAIN SIZE DISTRIBUTION AND AN APPROPRIATE SHAPE FACTOR. GOOD AGREEMENT IN THE VALUES WAS OBTAINED WHEN THE VARIATION IN PARTICLE SIZE WAS NOT TOO GREAT. /RATAOC/RRL(A)/

  • Supplemental Notes:
    • 27 Pp, 15 FIG, 3 TAB, 3 PHOT, 13 REF
  • Corporate Authors:

    Ontario Ministry of Transportation & Communic, Can

    1201 Wilson Avenue
    Downsview, Ontario M3M 1J8,   Canada 
  • Authors:
    • Davies, J R
    • Walker, R N
  • Publication Date: 1969-5

Subject/Index Terms

Filing Info

  • Accession Number: 00211255
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: May 16 1971 12:00AM