Six typical rock samples were polished in a reciprocating polishing machine to equilibrium. To eliminate the effects of aggregate shape, size, gradation, and edge effects, flat surfaces of rock were employed. With the Valentine limestone, the polish became smoother as finer abrasive was applied. The Hummelstown-Myerstown limestone performance was quite similar but the friction level was lower. With diabase samples it was found that no specific abrasive size produces the highest polish of a particular type of rock. With lithic sandstone, similar behavior was noted as in the previous tests except a higher friction level prevailed. Arkosic sandstone was noted to perform no differently in principle, except that it does so at a higher friction level. The quartzite behavior was found to be, next to the Valentine limestone, the most polish- susceptible rock because it consists of uniform mineral grains. Four conclusions were noted from the observations: The level of polish attainable depends on type of rock and petrography. Coarse-grained rocks require greater polishing effort than fine-grained ones. In general, the finer the abrasive is, the finer the ultimate polish will be, regardless of type or rock. Lastly, the coarser abrasives tend to scratch and roughen polished surfaces of soft rocks, such as limestone, but have little or no effect on hard-mineral rocks, such as diabase, sandstone, and quartzite.

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References;
  • Pagination: pp 54-56
  • Monograph Title: Pavement design, evaluation and performance
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00156003
  • Record Type: Publication
  • ISBN: 0309220710
  • Files: TRIS, TRB
  • Created Date: Aug 15 1977 12:00AM