Investigations into existing road pavements and subgrades in the ACT

An investigation was undertaken into the causes of premature distress in the arterial road pavements in Canberra. They consist of 40 to 50 mm bituminous concrete over a crushed or natural gravel base. Some have a low quality natural gravel base, and were designed for a 20 year life but were extensively distressed (cracking and rutting) after 10 years and have a good riding quality (low roughness). The investigation examined 27 adjacent sound and distressed areas of pavement, (similar construction, traffic and environmental factors) to determine the reasons for the difference in performance between the sections. Measurements included: surface condition (rut depth, extent of cracking etc); surface deflection; bituminous concrete density and air voids; basecourse and subbase material properties (atterburg limits, grading etc), moisture content, gradation, density; subgrade CBR and moisture content; traffic usage. The causes of distress appeared to be: wetter basecourse material than assumed in design; lower subgrade CBR than assumed in design; insufficient subgrade cover; and out of specification crushed rock basecourse. The report contains details of the data collected and its analysis. (Appendices are separate to this report and available from ARRB on request) (a).

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  • Corporate Authors:


    Melbourne, Victoria  Australia 
  • Authors:
    • Martin, M A
    • Teo, L T
    • Ryan, J A
  • Publication Date: 1981-3


  • English

Media Info

  • Pagination: 122P
  • Serial:
    • Issue Number: AIR 322-1

Subject/Index Terms

Filing Info

  • Accession Number: 01438583
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 24 2012 9:38PM