PHYSICAL PROPERTIES OF ASPHALT

STUDY WAS CONDUCTED TO DEVELOP INFORMATION ON THE HARDENING CHARACTERISTICS OF ASPHALT CEMENTS USED BY THE ARKANSAS HIGHWAY DEPARTMENT DURING HOT PLANT MIXING AND DURING SERVICE IN PAVEMENTS. ASPHALT CEMENTS FROM THREE SOURCES WITHIN THE STATE WERE USED IN THIRTEEN PAVING CONTRACTS. SAMPLES OF ASPHALT AND PAVING MIXTURE WERE OBTAINED FROM EACH JOB AT THE TIME OF CONSTRUCTION. PAVEMENT SAMPLES REPRESENTING THESE MATERIALS WERE OBTAINED THREE TO SIX MONTHS AFTER CONSTRUCTION AND AGAIN AFTER 21 TO 42 MONTHS SERVICE. EXTRACTION AND RECOVERY TESTS WERE MADE ON THE MIXTURES AND PAVEMENT SAMPLES AND THE RECOVERED ASPHALTS WERE TESTED FOR PENETRATION AND DUCTILITY AT 77 F AND 60 F AND VISCOSITY AT 140 F. PAVING MIXTURES LOOSE AND COMPACTED AND STORED UNDER WATER IN THE LABORATORY WERE TESTED TO DETERMINE ASPHALT HARDENING. A LABORATORY STUDY OF THE EFFECT OF MIXING ON HARDENING ALSO WAS MADE. THE PRINCIPAL FINDINGS OF THE STUDY WERE: THE VARIATION IN MIXING TEMPERATURES ON THE VARIOUS JOBS WAS NOT WIDE IN RANGE AND THERE WAS NO INDICATION OF CHANGE IN THE PHYSICAL PROPERTIES DUE TO DIFFERENT MIXING TEMPERATURES. OVERALL RESULTS INDICATE THAT FROM 25 TO 30 PERCENT OF THE PENETRATION OF THE ASPHALT WAS LOST DURING MIXING. THE DATA INDICATE THAT THE LOSS IN PENETRATION DURING MIXING APPROXIMATES THE LOSS DURING THE FIRST THREE YEARS OF PAVEMENT LIFE IF PENETRATION IS TO BE USED AS A CRITERION OF LIFE. THE LOSS OF DUCTILITY DURING MIXING WAS MUCH GREATER THAN THE LOSS DURING THE FIRST THREE YEARS OF PAVEMENT SERVICE. THE LOSS IN DUCTILITY DURING MIXING WAS ABOUT TWICE AS GREAT AS THE DECREASE DURING THE FIRST FORTY MONTHS IN THE PAVEMENT. THERE SEEMED TO BE VERY LITTLE DIFFERENCE BETWEEN THE CHANGES IN PHYSICAL PROPERTIES OF THE ASPHALT CEMENTS STORED IN THE LABORATORY AND DURING SERVICE IN THE PAVEMENTS. ALL OF THE PAVEMENTS WERE DENSE GRADED AND THE SURFACES ARE VERY TIGHT. THE LOSS OF PENETRATION DURING MIXING OF THE SAMPLES IN THE LABORATORY COMPARED CLOSELY WITH THAT LOSS DURING MIXING IN THE PUGMILLS ON THE JOB. /BPR/

  • Supplemental Notes:
    • Hpr-1/6/, BPR ITEM 6, HRC-17
  • Corporate Authors:

    Arkansas State Highway Department

    Little Rock, AR  USA  72203

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Authors:
    • Bissett, J R
  • Publication Date: 1969-6

Subject/Index Terms

Filing Info

  • Accession Number: 00210419
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Oct 27 1994 12:00AM