RELATION BETWEEN WEAR AND PHYSICAL PROPERTIES OF ROADSTONES

ONE ASPECT IN THE SKID-RESISTANT LIFE OF A PAVEMENT IS THE POLISHING OF INDIVIDUAL ROADSTONES BY ABRASIVES ON THE ROAD. THE RELATED PROBLEM STUDIED HERE IS THE GRADUAL WEAR (MICROSCOPIC SCALE) OF HOMOGENEOUS ROADSTONES TO DETERMINE THE PERTINENT PHYSICAL PROPERTIES OF THESE MINERALS IN THE WEAR PROCESS. WEAR IS MEASURED AS A WEIGHT LOSS OF MATERIAL. A BRIEF REVIEW OF WEAR IS GIVEN. A WIDE RANGE OF CONCEPTS EXIST, MOST STUDIES PERTAINING TO METALS. SOME OF THE IMPORTANT PARAMETERS ARE MELTING TEMPERATURE, HARDNESS, ELASTIC MODULUS, AND ENERGY. TEN MINERAL SAMPLES, PREDOMINATELY OXIDES, WERE HELD AGAINST THE RUBBER TRACKS OF A ROTATING DRUM IN THE PRESENCE OF DRY FINE ABRASIVES. THREE LOADS AND SPEEDS WERE TESTED FOR EACH OF THREE DIFFERENT ABRASIVES. THESE TEST CONDITIONS SIMULATED ACTUAL PAVEMENT EXPERIENCE. MICROSCOPIC PHOTOGRAPHS OF WORN SURFACES REVEALED TWO PHENOMENA: SCRATCHING AND PITTING. RAPIDLY WEARING MINERALS SUFFERED BOTH TYPES OF DAMAGE WHILE SLOW WEARING MINERALS DISPLAYED NO SCRATCHING, ONLY A SMALL AMOUNT OF PITTING. RAPID WEAR OCCURRED WHEN THE ABRASIVE WAS HARDER THAN THE MINERAL. WEAR WAS PROPORTIONAL TO LOAD AND INVERSELY PROPORTIONAL TO HARDNESS. THE SLOW WEAR OF MINERALS SOFTER THAN THE ABRASIVE WAS INDEPENDENT OF LOAD. LIMITED EVIDENCE SUGGESTED THAT THIS WEAR DEPENDED ON THE RATIO OF SURFACE TO STRAIN ENERGY IN A GIVEN MINERAL. PITTING WAS RELATED TO ENERGY CONCEPTS WHILE SCRATCHING WAS RELATED TO HARDNESS. NO CORRELATION COULD BE ACHIEVED BETWEEN WEAR AND MELTING TEMPERATURE OR MODULUS. HARDNESS WAS FOUND TO BE THE MOST IMPORTANT PARAMETER IN THE RAPID WEAR OF HOMOGENEOUS MINERALS. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 56-68
  • Monograph Title: Control of pavement slipperiness: asphalt pavement cracking
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00217786
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jul 28 1994 12:00AM