DESIGN OF REHABILITATION TREATMENTS FOR NEW ZEALAND'S THIN-SURFACED UNBOUND GRANULAR PAVEMENTS

Most thin-surfaced unbound granular pavements are rehabilitated by overlaying with an unbound granular material and surfaced with a chip seal (thin-surfacing). The unbound granular overlay thickness is the difference between the total granular thickness required for future traffic and the granular thickness required for past traffic as determined from the design chart. However, where there are signs of shoving or other indications of a weak and degraded aggregate base layer then a smoothing treatment will not be adequate. For this situation the appropriate rehabilitation is either in situ stabilization (to improve the strength of the aggregate base material) or to cover with a minimum thickness of unbound granular material (determined from the thickness design chart by assuming the existing pavement acts as a subbase). This method of unbound granular overlay design has resulted in significant cost savings over the past 20 years in rehabilitation treatments for New Zealand roads, as the existing pavement has been fully utilized. In 1995 New Zealand adopted the Austroads (the Association of State, Territory and Federal Road and Traffic Authorities in Australia) procedures for pavement design. The Austroads procedures encourage the use of mechanistic procedures for pavement design. By using the same assumptions as the design chart method for determination of granular overlay depths, a mechanistic design procedure for rehabilitation treatments was developed. This method produces comparable results and has the advantage of being able to design a range of rehabilitation treatments.

• Record URL:
  • https://doi.org/10.3141/1652-40
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=DESIGN+OF+REHABILITATION+TREATMENTS+FOR+NEW+ZEALAND'S+THIN-SURFACED+UNBOUND+GRANULAR+PAVEMENTS&author=G.+Arnold&publication_year=1999
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309065240
• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1652, Seventh International Conference on Low-Volume Roads, May 23-26, 1999, Baton Rouge, Louisiana, Volume 2.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Arnold, G
• Conference:
  • Seventh International Conference on Low-Volume Roads
  • Location: Baton Rouge, Louisiana
  • Date: 1999-5-23 to 1999-5-26
• Publication Date: 1999

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 43-50
• Serial:
  • Transportation Research Record
  • Issue Number: 1652
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Chip seals; Cost effectiveness; Granular materials; Mechanistic design; Pavement overlays; Rehabilitation; Soil stabilization
• Uncontrolled Terms: Unbound granular pavement
• Geographic Terms: New Zealand
• Subject Areas: Geotechnology; Highways; Maintenance and Preservation; Pavements; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 00763288
• Record Type: Publication
• ISBN: 0309065240
• Files: TRIS, TRB, ATRI
• Created Date: May 25 1999 12:00AM