DEFORMABILITY, FATIGUE AND HEALING PROPERTIES OF ASPHALT MIXES

IN ORDER TO BROADEN OUR KNOWLEDGE ON THE MECHANICAL PROPERTIES OF BITUMINOUS MIXES, A LABORATORY APPARATUS WAS DESIGNED. IN THIS APPARATUS, A VERTICAL SAMPLE VIBRATES AT VARIOUS TEMPERATURES AND DIFFERENT FREQUENCIES. THE FORCE AND THE DISPLACEMENT AT THE TOP OF THE SAMPLE ARE DIRECTLY MEASURED, ENABLING US TO DETERMINE THE COMPLEX MODULI AND TO STUDY THE FATIGUE BEHAVIOUR OF VARIOUS MIXES, UNDER CONDITIONS RATHER SIMILAR TO THOSE OF THEIR UTILISATION ON THE ROAD. FROM THE POINT OF VIEW OF DEFORMABILITY, RESULTS SHOWED THE SPECIAL INFLUENCE EXERTED ON THE COMPLEX MODULUS OF THE MIXES BY THE FOUR FOLLOWING PARAMETERS' TIME OF LOADING, TEMPERATURE, TYPE OF BITUMEN USED, AND VOID CONTENT OF THE MIX. IN COMPARISON WITH THESE PARAMETERS, IT SEEMS THAT OTHER FACTORS HAVE ONLY A SLIGHT EFFECT, AT LEAST IN THE RANGE EXAMINED BY US. BECAUSE OF THIS, WHEN USING THE STIFFNESS MODULUS OF THE BITUMEN, CALCULATED FROM VAN DER POELS MANOGRAPH, AS A REDUCED VARIABLE, IT IS POSSIBLE TO OBTAIN FROM PRECEEDING DATA AN APPROXIMATE VALUE OF THE STIFFNESS MODULUS OF A BITUMINOUS MIX. FROM THE POINT OF VIEW OF REPEATED FLEXURES FATIGUE TESTS CARRIED OUT ON VARIOUS MIXES CONFIRMED THE IMPORTANT PART PLAYED BY THE STRAIN' WHEN A MIX HAS A BEHAVIOUR WHICH IS PREDOMINANTLY ELASTIC, A LINEAR RELATION EXISTS BETWEEN THE LOGARITHM OF THE STRAIN AND THAT OF ITS LIFE. THE TYPE OF AGGREGATE AND TYPE OF BITUMEN HAVE A NOTICEABLE INFLUENCE ON THE LIFE OF BITUMINOUS MIXES, PARTICULARLY IN THE CASE OF RATHER LOW STRAIN AS OCCUR IN PAVEMENTS. ON THE OTHER HAND, THE HIGHER THE BINDER CONTENTS AND THE LOWER THE VOID CONTENTS ARE THE LONGER THE LIFE WILL BE. A CORRELATION WAS FOUND BETWEEN THE FATIGUE PRODUCED BY A LOADED WHEEL AND THAT PRODUCED BY OUR APPARATUS. ON THE OTHER HAND, REST PERIODS HAVE A BENIFICIAL EFFECT ON FATIGUED AND EVEN BROKEN BITUMINOUS MIXES. THE ABILITY OF MIXES TO HEAL WAS SHOWN PARTICULARLY AT RELATIVELY HIGH TEMPERATURES. HOWEVER, IT SEEMS THAT MANY PARAMETERS INFLUENCE THIS PHENOMENEN. IT HAS BEEN NOTED, THAT FOR TOTAL AND RAPID HEALING, IT IS NECESSARY THAT A SMALL STRESS ACTS PERMANENTLY ON THE MIX. /AUTHOR/

• Supplemental Notes:
  • Preprint VoL, PP 438-451, 17 FIG, 1 TAB, 4 PHOT, 8 REF, 1APP
• Authors:
  • Bazin, P
  • Saunier, J
• Conference:
  • Intl Conf Struct Design Asphalt Pvmts
• Publication Date: 1967-1

Subject/Index Terms

• TRT Terms: Aggregates; Binders; Bitumen; Bituminous mixtures; Deformation; Development; Dislocation (Geology); Fatigue (Mechanics); Fatigue tests; Force; Loading and unloading; Measurement; Mechanical properties; Samples; Temperature; Testing equipment; Vibration devices; Void ratios
• Uncontrolled Terms: Fatigue life; Laboratory equipment
• Old TRIS Terms: Loading time; Vibrators; Void
• Subject Areas: Geotechnology; Highways; Materials; Pavements;

Filing Info

• Accession Number: 00210668
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 15 1994 12:00AM