A comparison of unbound road design methods used in South Africa and New Zealand

This paper reports on the findings of a Bachelor of Engineering (Hons) final year research project undertaken in 2011 at The University of Auckland. This paper discusses the results of a critical comparison of two pavement design tools - CIRCLY (much used existing software in New Zealand) and RUBICON (a software developed in South Africa). Several existing pavements in New Zealand were modelled using these two software packages and the differences in the subgrade strain and predicted pavement life were evaluated. Pavement rehabilitation designs were obtained from each design tool and a comparative analysis of these designs were conducted and are reported in the paper. It was found that there were significant differences between the designs obtained from each tool. The differences were attributed to the following factors implemented differently in each design tool: the underlying assumptions of the subgrade material properties, the empirically derived subgrade failure criterion, and the assumed failure mechanism of basecourse failure in RUBICON. Furthermore, sensitivity analyses of the relationship between the subgrade strains and design life to the design inputs are discussed. Both design tools illustrated similar sensitivity in strains and design life to variations of basecourse modulus and thickness. Significant differences in design life as a function of modulus were found between the analytical tools.

• Authors:
  • Mok, J
  • Amin, A
  • Larkin, T
  • Wilson, D
• Conference:
  • Seventh International Conference on Maintenance and Rehabilitation of Pavements and Technological Control
  • Location: Auckland , New Zealand
  • Date: 2012-8-28 to 2012-8-30
• Publication Date: 2012-8

Language

• English

Media Info

• Pagination: 11p
• Serial:
  • Issue Number: 00181

Subject/Index Terms

• TRT Terms: Bituminous pavements; Computer programs; Durability; Pavement design; Physical properties
• Uncontrolled Terms: Design guide; International comparison; Pavement technology
• Geographic Terms: New Zealand; South Africa
• ATRI Terms: Bituminous pavement; Computer program; Design guide; Durability; International comparison; Pavement design; Pavement properties
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 01455780
• Record Type: Publication
• Source Agency: ARRB
• Files: ATRI
• Created Date: Nov 30 2012 2:52PM