THERMAL EXPANSION-CONTRACTION OF ASPHALTIC CONCRETE

AN INVESTIGATION ON THE BASIC ASPHALTS OF THERMAL EXPANSION AND CONTRACTION OF ASPHALTIC CONCRETE WAS CONDUCTED. ASPHALTIC CONCRETE EXHIBITS TWO DIFFERENT THERMAL COEFFICIENTS OF EXPANSION AND CONTRACTION SIMILAR TO ASPHALT CEMENT IN THE TEMPERATURE RANGE MINUS 10 TO 140 F. THESE HAVE BEEN CALLED THE SOLID AND FLUID THERMAL COEFFICIENTS. A TRANSITION TEMPERATURE WAS FOUND FOR ASPHALTIC CONCRETE. ABOVE THIS TEMPERATURE ASPHALTIC CONCRETE EXHIBITS ITS FLUID COEFFICIENT, AND BELOW, ITS SOLID COEFFICIENT. ASPHALT CONTENT WAS FOUND TO BE A MAJOR CONTRIBUTOR TO THERMAL- EXPANSION-CONTRACTION OF ASPHALTIC CONCRETE. A RELATIONSHIP WAS DERIVED WHICH PREDICTS THE THERMAL COEFFICIENT OF EXPANSION-CONTRACTION OF ASPHALTIC CONCRETE IN THE SOLID STATE. THE THERMAL EXPANSION OF THE ASPHALT AND QUARTZITE AGGREGATE USED WERE DETERMINED BY MEANS OF A DILATOMETER. ASPHALTIC CONCRETE WAS FOUND TO EXHIBIT A DIFFERENT THERMAL COEFFICIENT IN EXPANSION THAN IN CONTRACTION. PERMANENT LENGTH CHANGES WERE OBSERVED WHEN ASPHALTIC CONCRETE SPECIMENS WERE HEATED AND COOLED IN A FLUID STATE. THE THERMAL EXPANSION IN THE FLUID STATE IS LESS THAN THERMAL CONTRACTION RESULTING IN PERMANENT SHRINKAGE. THIS PHENOMENEN HAS BEEN ATTRIBUTED TO ABSORPTION OF ASPHALT INTO THE AGGREGATES AND BY DENSIFICATION OF THE ASPHALTIC CONCRETE CAUSED BY AN IRREVERSIBLE PROCESS OF EXPANSION AND CONTRACTION OF ASPHALT INTO THE AIR VOIDS. THE EXPANSION AND CONTRACTION IN THE SOLID STATE WERE IDENTICAL FOR FREE AND FRICTION CONDITIONS. THE TEST METHOD UTILIZING DIAL DEFLECTION GAGES PROVIDES AN EXCELLENT METHOD TO MEASURE THE THERMAL EXPANSION AND CONTRACTION OF ASPHALTIC CONCRETE IN THE SOLID AND FLUID STATE.

• Supplemental Notes:
  • 71 Pp, 30 FIG, 45 REF, 1 APP
• Corporate Authors:

  Utah State Department Highways

  /Materials and Test Division
  ,   United States 
• Authors:
  • JONES, G M
  • Darter, M I
  • Littlefield, G
• Publication Date: 1968-2

Subject/Index Terms

• TRT Terms: Adsorption; Asphalt; Asphalt concrete; Asphalt content; Contraction; Deflection tests; Densification; Extensometers; Fluid dynamics; Length; Mathematical analysis; Shrinkage; Solid state devices; Temperature; Thermal expansion
• Uncontrolled Terms: Change; Transition zones
• Old TRIS Terms: Solid state
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00210766
• Record Type: Publication
• Files: TRIS, STATEDOT
• Created Date: May 24 1994 12:00AM