Test methods to identify problem bitumens

In recent years a number of cases of delayed field hardening ('tenderness') of bitumens used in sprayed seal and asphalt work have been reported. This phenomenon is related to the initial stages of surfacing life. In sprayed seal work, significant bleeding and loss of aggregate is noticeable, whilst in asphalt work, shoving under normal compaction, and heavy bleeding and rutting under traffic, occur. However, in many instances, particularly in sprayed seal work, this tenderness does not affect the long term performance. In the majority of instances there are other variables which may contribute to the tenderness problem, with the bitumen being only one factor. For example, excessive application rates, too much flux or cutter in sprayed seals, incorrect aggregate grading in asphalt work, contamination of bitumen, or seasonal heavy traffic may lead to the incorrect observation that the quality of the bitumen is the cause of the problem. This intermittent problem is not detectable by the Australian Standard AS2008, which governs the properties of bitumen for pavements, as the bitumens in question generally conformed to the above specification. Requirements of the present specification are based on the physical properties of the bitumen. This report discusses the investigations directed into identifying the properties of bitumen which are associated with tenderness, and determining the suitability of laboratory tests as identifiers of tender bitumens.

  • Corporate Authors:

    South Australia. Department of Road Transport. Materials Technology Research and Development Program

    Adelaide, South Australia   

    South Australia. Department of Road Transport. Materials Services Section

    ,    
  • Publication Date: 1992-8

Language

  • English

Media Info

  • Pagination: 47p
  • Serial:
    • Issue Number: 18-1

Subject/Index Terms

Filing Info

  • Accession Number: 01433397
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 24 2012 5:40PM