METHODS OF IMPROVING COMPACTION OF DENSE COATED MACADAM

The author discusses the need for bituminous materials, in common with other road materials, to be well compacted to give good performance. Reference is made to the variation of density with roller passes (three-wheel roller) across the laid width of dense bitumen macadam road bases, due to the number of roller passes in the near side wheel path being less than half that at the centre of the laid width. Methods of increasing compaction in the wheel-paths are described, e.g. by the use of a tandem roller operating specifically in the wheel-path zones. The important factors affecting the level of compaction obtained on the road are described under the headings of compactive effort, material temperature during rolling and binder content. Reference is made to pilot-scale experimental facilities available at the Transport and Road Research Laboratory to investigate these factors. In a consideration of the measurement of the state Transport and Road Research Laboratory to investigate these has the advantage of providing information on the variation of density with depth. Cylindrical cores are placed in a vertical position on a platform which rotates as it descends through a gamma-ray beam emanating from a one-millicurie source of Caesium 137. The associated detection and measuring apparatus is described. Information is also given on an in-situ nuclear density gauge and mobile nuclear density gauges which have been developed to provide a continuous record of density variations along the road. The relationship between compaction and pavement performance is discussed. /TRRL/

  • Corporate Authors:

    INSTITUTE OF ASPHALT TECHNOLOGY

    PAPER MEWS PLACE, 290 HIGH STREET
    DORKING, SURREY  United Kingdom  RH4 1QT

    INSTITUTE OF ASPHALT TECHNOLOGY

    PAPER MEWS PLACE, 290 HIGH STREET
    DORKING, SURREY  United Kingdom  RH4 1QT
  • Authors:
    • Powell, W D
  • Publication Date: 1978-5

Media Info

  • Features: Figures; Photos; References;
  • Pagination: p. 7
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00188287
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Mar 28 1979 12:00AM