RELATIONSHIP OF SKID RESISTANCE TO PETROGRAPHY OF AGGREGATES

Results of this project show that petrographic properties of aggregates play the chief role in skid resistance on bituminous concrete highways. Important petrographic properties are mineral hardness, grain or crystal size and angularity of grains. Most important single property is mineral hardness. At least 5 on the Mohs Scale of Hardness is required to maintain asperities. Differential hardness such as is present in most sandstones (between the grain and matrix) and in most igneous and metamorphic rocks (between the various component minerals) tends to maintain a rough texture under the wear of traffic. Maximum polish of low silica limestone aggregates was achieved by 750,000 vehicle passes whereas a quartzite required over 2,000,000 for maximum polish. Weather dependent factors cause variations in skid resistance. The chief causes of these variations are changes in surface temperatures and size distribution of abrasive detritus. Normal seasonal variations in skid resistance are very pronounced because of compounding influences. (Author Modified Abstract)

  • Supplemental Notes:
    • Sponsored in part by Federal Highway Administration, Washington, D.C.
  • Corporate Authors:

    Pennsylvania Department of Transportation

    Bureau of Materials, Testing and Research, 1118 State State
    Harrisburg, PA  USA  17112
  • Authors:
    • Furbush, M A
    • Styers, K E
  • Publication Date: 1972-7-1

Media Info

  • Pagination: 44 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00046299
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: PDT-68-22-3 Final Rpt
  • Files: NTIS, STATEDOT
  • Created Date: Jul 31 1973 12:00AM