THE EFFECT OF CHEMICAL COMPOSITION ON THE RHEOLOGICAL PROPERTIES OF ASPHALTS

RHEOLOGICAL PROPERTIES AND CHEMICAL COMPOSITIONS WERE DETERMINED FOR 9 PAVING-GRADE ASPHALT FOUR OF THE ASPHALTS WERE OBTAINED FROM ARKANSAS PAVING PROJECTS, AND 5 WERE FROM THE AC-10 SERIES SUPPLIED BY THE U. S. BUREAU OF PUBLIC ROADS. A SLIDING PLATE MICROVISCOMETER WAS USED TO OBTAIN THE FLOW PROPERTIES AT 45 DEGREES F, 77 DEGREES F AND 120 DEGREES F. VISCOELASTIC BEHAVIOR AT 45 DEGREES F WAS MEASURED BY THE METHOD OF STRESS RELAXATION AT CONSTANT STRAIN IN A CONICYLINDRICAL VISCOMETER. CHEMICAL COMPOSITIONS WERE DETERMINED BY SEPARATING THE ASPHALTS INTO FIVE FRACTIONS BY A MODIFIED CORBETT-SWARBRICK CHROMATOGRAPHIC METHOD. A LEAST-SQUARES TECHNIQUE AND COMPUTER PROGRAM WERE DEVELOPED FOR THE DETERMINATION OF POWER-LAW PARAMETERS AND EXPERIMENTAL VARIABILITY FROM MICROVISCOMETER DATA. AN AREA-CORRECTION TECHNIQUE WAS USED WITH THE MICROVISCOMETER TO ALLOW PLATE DISPLACEMENTS OF OVER 2,500 MICRONS. THE EFFECT OF TEMPERATURE ON VISCOSITY WAS SATISFACTORILY REPRESENTED BY PLOTS BASED ON THE WALTHER EQUATION, AND BY CHARACTERISTIC TEMPERATURES OBTAINED FROM THE WILLIAMS-LANDEL-FERRY EQUATION. THE APPARENT VISCOSITY EVALUATED AT A CONSTANT POWER INPUT WAS THE MOST USEFUL TYPE OF VISCOSITY. EQUATIONS WERE OBTAINED FROM MULTIPLE-LINEAR- REGRESSION ANALYSIS WHICH PROVIDED SIGNIFICANT CORRELATIONS OF THE FLOW PROPERTIES AT 120 DEGREES F WITH THE CHEMICAL COMPOSITIONS. HOWEVER, THE COMPOSITION DATA ALONE WERE NOT SUFFICIENT TO DESCRIBE THE FLOW BEHAVIOR AT THE LOWER TEMPERATURES. THE COEFFICIENT OF THERMAL EXPANSION WAS FOUND TO BE A SIGNIFICANT QUANTITY FOR THE DESCRIPTION OF THE FLOW PROPERTIES AT THE LOWER TEMPERATURES. REGRESSION EQUATIONS WERE OBTAINED FOR THE FLOW PROPERTIES AT 45 DEGREES F AND 77 DEGREES F AND FOR THE WALTHER VISCOSITY- TEMPERATURE SLOPE WHEN THE EXPANSION COEFFICIENTS WERE INCLUDED IN THE REGRESSION ANALYSIS. FROM THE RESULTS OF THIS STUDY, AND THE REVIEW OF THE LITERATURE, IT WAS CONCLUDED THAT THE FLOW BEHAVIOR OF ASPHALTS IN THE LOWER RANGE OF SERVICE TEMPERATURES IS MORE DEPENDENT ON FACTORS SUCH AS ASSOCIATION AND COLLOIDAL STATE THAN ON THE RELATIVE CONTENT OF SPECIFIC TYPES OF COMPOUNDS. /AUTHOR/

  • Supplemental Notes:
    • Hpr-1/4/, BPR-HRC-21, STATE-K-457
  • Corporate Authors:

    University of Arkansas, Fayetteville

    Fayetteville, AR  United States 

    Arkansas State Highway Department

    Little Rock, AR  United States  72203
  • Authors:
    • Lamb, C W
  • Publication Date: 1967-2

Subject/Index Terms

Filing Info

  • Accession Number: 00210372
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Jul 21 1994 12:00AM