CHEMICAL COMPONENTS OF ASPHALT: PHASE III, PREPARATION AND TESTING OF BLENDS OF COMPONENTS

THE RELATION BETWEEN ASPHALT PROPERTIES AND ASPHALT COMPOSITION WAS DETERMINED BY THE ACID PRECIPITATION METHOD (MODIFIED ROSTLER-STERNBERG ANALYSIS). ASPHALTS WERE PREPARED BY BLENDING OF THE SEPARATED COMPONENTS AND TESTING THE "PREPARED" ASPHALTS TO DETERMINE: (1) WHETHER ORIGINAL PROPERTIES COULD BE ATTAINED BY RECONSTITUTING THE ORIGINAL ASPHALT FROM ITS COMPONENTS AND (2) WHETHER IMPROVEMENT IN QUALITY COULD BE ACHIEVED BY CHANGING COMPOSITION. THE POSTULATE THAT THE PROPERTIES OF ASPHALTS DEPEND PRIMARILY ON THE PROPORTIONS OF THE FRACTIONAL COMPONENTS COMPRISING THEM, HAS BEEN CONFIRMED. BY RECONSTITUTING ASPHALTS STEPWISE FROM THEIR FRACTIONS IT WAS ESTABLISHED THAT ASPHALTS COULD BE REBLENDED FROM THE COMPONENT CONCENTRATES TO MATCH, WITHIN ACCEPTABLE LIMITS, THE PROPERTIES OF THE ORIGINAL ASPHALT, THUS ASSURING THAT THE COMPONENTS IN THESE CONCENTRATES HAD NOT BEEN APPRECIABLY ALTERED DURING THE PREPARATIVE PROCEDURES FROM THE COMPONENTS ORIGINALLY PRESENT IN THE ASPHALT. CROSSBLENDING OF THE FIVE COMPONENTS PRODUCED FROM FOUR ASPHALTS SHOWED THAT, WITH THE POSSIBLE EXCEPTION OF THE ASPHALTENES FRACTION, COMPONENTS FROM DIFFERENT ASPHALTS ARE SUFFICIENTLY SIMILAR IN PROPERTIES TO BE INTERCHANGEABLE. BY MATCHING THE PERCENTAGE COMPOSITION OF COMPONENTS EXISTING IN A DURABLE ASPHALT, AN ASPHALT OF GOOD DURABILITY COULD BE PRODUCED FROM COMPONENTS OF AN ASPHALT OF POOR DURABILITY. CONVERSELY, BLENDING COMPONENTS FROM AN ASPHALT OF GOOD DURABILITY TO THE PERCENTAGE COMPOSITION OF AN ASPHALT OF POOR DURABILITY RESULTED IN AN ASPHALT OF POOR DURABILITY. THE DURABILITY OF AN ASPHALT, AS MEASURED BY EMBRITTLEMENT, HAS THUS BEEN SHOWN TO BE DEPENDENT ON THE PROPORTIONS OF FRACTIONAL COMPONENTS PRESENT, AND THE EFFECT OF THE SOURCE OF THE COMPONENTS WAS SHOWN TO BE MINOR. THE FINDINGS OF THE STUDY DEMONSTRATE THAT ASPHALT QUALITY CAN BE IMPROVED BY BLENDING TO CHANGE THE PROPORTIONS OF MALTENES COMPONENTS TO DESIRABLE COMPOSITION RATIOS. CROSSBLENDING OF ASPHALTENES AND MALTENES FRACTIONS AMONG THE FOUR ASPHALTS STUDIED INDICATED THAT THE ASPHALTENES FRACTIONS ARE NOT EQUALLY AS INTERCHANGEABLE AS THE MALTENES COMPONENTS. ALTHOUGH THE DIFFERENCES BROUGHT ABOUT BY INTERCHANGING ASPHALTENES ARE SMALLER THAN THOSE RESULTING FROM DIFFERENCES IN THE COMPOSITION OF THE MALTENES, THE OBSERVED DIFFERENCES INDICATE THAT THE EFFECTS OF BOTH THE MOLECULAR WEIGHT AND THE CHEMICAL NATURE OF THE ASPHALTENES REQUIRE FURTHER STUDY TO PREDICT PROPERTIES OF ASPHALTS MORE CLOSELY FROM CHEMICAL COMPOSITION. /AUTHOR/

  • Supplemental Notes:
    • Hpr-pr-1 (7), D-3-31
  • Corporate Authors:

    California Division of Highways

    Bridge Department
    Sacramento, CA  United States  05914

    Materials Research & Development Inc

    ,    

    Bureau of Public Roads /US

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

Subject/Index Terms

Filing Info

  • Accession Number: 00210429
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: May 13 2000 12:00AM