CONSISTENCY AND QUANTITY CHANGES OF 60-70 GRADE ASPHALT IN HOT PLANT MIXES

THE STUDY WAS CONDUCTED TO: (1) DETERMINE THE PENETRATION OF 60-70 GRADE ASPHALT CEMENT AT 77F PRIOR TO ENTRY INTO THE HOT PLANT MIXER, ON THE ASPHALT RECLAIMED AFTER MIXING, ON THE ASPHALT RECLAIMED AFTER A PERIOD OF SERVICE AND (2) DETERMINE THE ASPHALT CONTNENT IN 60-70 GRADE ASPHALT CEMENT FROM SAMPLES OF MIX TAKEN IMMEDIATELY AFTER SPREADING AND FROM SAMPLES TAKEN AT THE SAME LOCATION AFTER A PERIOD OF SERVICE. RESULTS WERE COMPARED WITH SIMILAR TESTS IN WHICH 85-100 PENETRATION GRADE WAS USED. IT WAS CONCLUDED THAT ASPHALT CONTENT OF BITUMINOUS MIXTURES TENDS TO DECREASE WITH AGE, BUT 60-70 GRADE ASPHALT MIXTURES TENT TO LOSE LESS QUANTITY THAN THOSE USING 85-100 GRADE. TEST RESULTS ALSO INDICATED THAT THE RATE OF ASPHALT HARDENING IS LESS IN MIXTURES IN WHICH 60-70 GRADE IS USED THAN IN THOSE IN WHICH 85-100 GRADE IS USED, ALTHOUGH BY THE END OF 6.5 YEARS' SERVICE THE ASPHALT HARDNESS WILL BE APPROXIMATELY THE SAME FOR BOTH GRADES IF THEY COME FROM THE SAME SOURCE AND HAVE SIMILAR MIXING AND WEATHER CONDITIONS. INDICATIONS ARE THAT THERE IS NO SIGNIFICANT DESIGN PERIOD DIFFERENCE IN THE ASPHALT HARDNESS WITH USE OF 60-70 OR 85-100 GRADE. /AUTHOR/

  • Corporate Authors:

    Oregon Department of Transportation

    Materials and Research Section, 800 Airport Road, SE
    Salem, OR  United States  97310

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • White, O A
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00210433
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Report/Paper Numbers: 5142-06
  • Files: TRIS, STATEDOT
  • Created Date: Jul 14 1970 12:00AM