CONTROL OF ASPHALT PAVEMENT RUTTING WITH ASBESTOS FIBER

RUTTING-TYPE FAILURES ARE INDUCED IN MINIATURE ASPHALT HIGHWAY PAVEMENTS WITH A TRAFFIC SIMULATOR MACHINE, WHICH DUPLICATES CRITICAL FACTORS OF ROADWAY TEMPERATURE GRADIENTS, VEHICLE TIRE PRESSURE, AND ACCUMULATED WHEEL PASSES. AN INVESTIGATION WAS MADE OF THE BENEFICIAL EFFECTS VARIOUS MINERAL ADDITIONS PRODUCED IN PAVEMENTS EXPOSED TO SEVERE SERVICE CONDITIONS. OF THE ADMIXTURES USED, ONLY A MIXTURE CONTAINING FINE CHRYSOTILE ASBESTOS FIBERS PREVENTED EXCESSIVE RUTTING AT NORMAL AND INCREASED ASPHALT CONTENTS. ASBESTOS MIXES HAVE SURPRISINGLY LOW SENSITIVITY TO ASPHALT CONCENTRATION OVER THE RANGE FROM 5.0 TO 8.0 WEIGHT PERCENT. WITH 85 TO 100 PENETRATION GRADE ASPHALT, ASBESTOS RAISED THE CRITICAL RUTTING TEMPERATURE TO LEVELS REACHED BY PAVEMENTS ON AN EXTREMELY HOT SUMMER DAY. AN ADDITIONAL ELEVATION OF ABOUT 20 F WAS ACHIEVED WITH 60 TO 70 PENETRATION ASPHALT AND SUITABLE CONTROL OF FIBER-ASPHALT RATIOS. BENCH SCALE TEMPERATURE-SUSCEPTIBILITY EVALUATIONS SUGGEST SIMPLE LABORATORY TEST PROCEDURES CAN MEASURE CRITICAL DESIGN PROPERTIES OF ASBESTOS-ASPHALT MIXTURES. THE STATIC TEMPERATURE INDENTATION PROCEDURE APPEARS TO YIELD RESULTS THAT COMPARE FAVORABLY WITH MINIATURE HIGHWAY TRAFFIC SIMULATOR MACHINE PERFORMANCES. FIBER LINKAGE IS A MECHANISM THAT MAY EXPLAIN THE RESISTANCE TO RUTTING WHICH ASBESTOS IMPARTS IN ASPHALT PAVING MIXTURES. SELECTIVE ADSORPTION ON THE SHORT CHRYSOTILE ASBESTOS FIBER COULD BOND OR LINK TOGETHER THE HEAVY, VISCOUS ASPHALT FRACTION. PAVEMENT STABILITY AGAINST RUTTING WOULD THEN DEPEND ONLY ON THE STRENGTH OF THE HEAVY FRACTION, THE AMOUNT PRESENT IN THE PAVING ASPHALT, AND THE PROPORTION ADSORBED BY THE ASBESTOS FIBER. /AUTHOR/

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  • Authors:
    • Speer, Thomas L
    • Kietzman, John H
  • Conference:
  • Publication Date: 1962

Media Info

  • Media Type: Print
  • Features: Appendices; Figures; References; Tables;
  • Pagination: pp 64-82
  • Monograph Title: Symposium on mineral fillers for bituminous mixtures
  • Serial:

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Filing Info

  • Accession Number: 00210842
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Aug 5 1994 12:00AM