THERMALLY INDUCED DENSIFICATION OF ASPHALTIC CONCRETE

THIS INVESTIGATION WAS DESIGNED TO DETERMINE IF THERE WAS ANY INCREASE IN BULK DENSITY OF ASPHALTIC CONCRETE SAMPLES AS A RESULT OF BEING EXPOSED TO TEMPERATURE CYCLES. TWELVE DESIGN MIXES WERE FORMED INTO FORTY-EIGHT MARSHALL BRIQUETTES. FOUR BRIQUETTE SAMPLES WERE FORMED FOR EACH OF THE TWELVE MIXES. THEY WERE DIVIDED INTO TWO SETS OF CONTROL SAMPLES AND TWO SETS OF TEST SAMPLES. THE TEST SAMPLES WERE PLACED IN AN ENVIRONMENTAL CHAMBER AND WERE SUBJECTED TO 300 TEMPERATURE CYCLES RANGING FROM 50F TO 135F. THE CONTROL SAMPLES REMAINED AT ROOM TEMPERATURE FOR DETERMINATION OF BULK DENSITY. THE TREE DESIGN VARIABLES FOR THE TWELVE DESIGN MIXES WERE AGGREGATE ABSORPTION, ASPHALT VISCOSITY AND PER CENT OF ASPHALT CONTENT. TWO UNCOMPACTED RICE SAMPLES WERE MADE FOR EACH OF THE DESIGN MIXES WHICH CONTAINED OPTIMUM ASPHALT CONTENT. RICE SAMPLES WERE DIVIDED INTO CONTROL AND TEST SAMPLES. THE TEST SAMPLES WERE SUBJECTED TO THE SAME TEMPERATURE CYCLES AS THE TEST BRIQUETTES AND WERE USED TO DETERMINE THE THEORETICAL MAXIMUM DENSITY OF THE BRIQUETTES. ALL TEST SAMPLES WERE FOUND TO HAVE INCREASED SIGNIFICANTLY IN BULK DENSITY BUT IN VARYING AMOUNTS DEPENDING UPON THE VARIABLES IN THE MIXES. A FACTORIAL DESIGN WAS USED IN THIS STUDY MAKING IT POSSIBLE TO MAKE COMPARISONS BETWEEN SAMPLES WITH SEVERAL VARIABLES AND THE EFFECT OF ANY INTERACTION BETWEEN VARIABLES COULD BE DETECTED. AN ANALYSIS OF VARIANCE WAS CONDUCTED ON THE TEST RESULTS USING PER CENT INCREASE IN BULK DENSITY AS A STATISTIC. A LIST OF FIFTEEN VARIABLES AND INTERACTIONS BETWEEN VARIABLES WAS MADE AND OF THEM NONE WERE FOUND TO BE SIGNIFICANT USING AN ALPHA ERROR OR 0.05. LOW VISCOSITY PRODUCED GREATER INCREASE IN BULK DENSITY OF THE SAMPLE THAN HIGH VISCOSITY. HIGH ABSORPTIVE AGGREGATES PRODUCED GREATER INCREASE IN BULK DENSITY THAN LOW ABSORPTIVE AGGREGATES. GREATER PERCENTAGES OF ASPHALT CEMENT IN THE MIX PRODUCED GREATER INCREASES IN BULK DENSITY. /AUTHOR/

• Supplemental Notes:
  • Vol 38, pp 660-683, 13 FIG, 10 TAB, 9 REF
• Authors:
  • Ellis, D S
  • JONES, G M
  • Littlefield, G
  • Parr, W K
  • Campen, W H
  • Smith, Theodore A
  • Erickson, L C
  • Johnston, I E
  • Krchma, L C
• Conference:
  • Association of Asphalt Paving Technologists Proc
• Publication Date: 1969-2

Subject/Index Terms

• TRT Terms: Absorption; Aggregates; Analysis of variance; Asphalt; Asphalt cement; Asphalt concrete; Asphalt content; Bulk density; Coal fuels; Fuels; Temperature; Viscosity
• Old TRIS Terms: Briquets
• Subject Areas: Data and Information Technology; Energy; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00211513
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM