Better compaction achieved at little or no extra cost has been shown to improve the performance of dense roadbase and basecourse macadam. In the present work the deformation resistance of economically attractive coated macadams of low binder content has been measured for a range of aggregates representing the more important petrological types. Samples of material containing 40 mm maximum size aggregate and either 100 pen bitumen or 54 evt tar were cut from experimental pavements and their deformation resistance was measured in realistic tracking tests at 30 deg C. The results for all materials emphasise the importance of good compaction to provide adequate deformation resistance. Gravel mixtures had less deformation resistance than crushed rock or slag materials. For a wide range of binder content, which includes that specified for roadbase and basecourse macadam, the deformation resistance of all materials is either improved or is not affected by reducing binder content. It appears particularly advantageous, from the point of view of deformation resistance, to reduce the binder content of basecourse macadam to equal that of roadbase macadam. Other parameters related to pavement performance are also being studied so that broader-based conclusions can be made concerning the possibility of reducing binder content. (Author/TRRL)

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Authors:
    • LEECH, D
    • Selves, N W
  • Publication Date: 1980

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 22 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00330777
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Report/Paper Numbers: TRRL SR626 Monograph
  • Files: ITRD, TRIS, ATRI
  • Created Date: Aug 15 1981 12:00AM