INTERIM REPORT ON THE LABORATORY CONSIDERATIONS FOR THE USE OF SYNTHETIC AGGREGATES FOR HOT-MIX ASPHALT PAVEMENTS

THIS INTERIM REPORT PRESENTS DATA PERTAINING TO THE PHYSICAL CHARACTERISTICS OF LABORATORY PREPARED BITUMINOUS CONCRETE MIXTURES USING LIGHTWEIGHT AGGREGATES FROM SEVEN SOURCES. TWO AGGREGATE MIXTURES WERE STUDIED, ONE CONTAINING ALL LIGHTWEIGHT AGGREGATE AND ANOTHER CONTAINING FINE NATURAL SAND FOR THE FINE AGGREGATE FRACTION, AND LIGHTWEIGHT AGGREGATE FOR THE COARSE FRACTION. EACH AGGREGATE MIXTURE WAS INVESTIGATED WITH VARIOUS ASPHALT CONTENTS. THE CHARACTERISTICS STUDIED AND RESULTS OF TESTS ARE AS FOLLOWS' /1/ LABORATORY COMPACTION DEGRADATION-USING THE TEXAS GYRATORY METHODS OF COMPACTION, DEGRADATION, AS MEASURED BY INCREASE IN SURFACE AREA, WAS FOUND TO BE RELATIVELY MINOR, /2/ ASPHALT ABSORPTION-DEPENDING ON PARTICLE SIZE AND MATERIAL SOURCE ABSORPTION VARIED FROM 2.0 TO 15.4 PER CENT, /3/ WATER SUSCEPTIBILITY-TEST WERE MADE ON COMBINED LIGHTWEIGHT AGGREGATE AND NATURAL SAND SO THE WATER SUSCEPTIBILITY OF THE LIGHTWEIGHT AGGREGATE ALONE IS NOT ALREADY DEFINED, HOWEVER AT HIGH ASPHALT CONTENTS THE INDEX OF RETAINED STRENGTH IS ACCEPTABLE, /4/ PERCENT SWELL AND EXPANSION PRESSURE TESTS SHOW THE MIXTURES INVESTIGATED TO BE ACCEPTABLE, AND /5/ AIR PERMEABILITY TESTS SHOW THAT PERMEABILITY DECREASES WITH INCREASED ASPHALT CONTENT, HOWEVER THE AUTHORS REPORT POOR REPEATABILITY AND REPRODUCIBILITY WITH THE TEST PROCEDURE. OTHER TESTS PERFORMED INCLUDE HVEEM STABILITY,COHESION AND DENSITY. THE THE AUTHORS DO NOT FORWARD ANY CONCLUSIONS OR SUGGEST DESIGN CRITERIA FOR MIXTURES CONTAINING LIGHTWEIGHT AGGREGATE. /BPR/

  • Supplemental Notes:
    • Hpr-1/6/, BPR-16, 2-14-63-51
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  USA  76011

    Texas State Department of Highways & Public Transp

    11th and Brazos Streets
    Austin, TX  USA  78701
  • Authors:
    • Gallaway, B M
    • Harper, W J
  • Publication Date: 1967-2

Subject/Index Terms

Filing Info

  • Accession Number: 00210366
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Jun 9 1994 12:00AM