Bitumen in New Zealand: performance based asphalt binder specification

This paper discusses performance data from New Zealand bitumen over the last decade. It compares the rheological properties of bitumen with the performance based mix properties and field performance. A new performance based binder specification is proposed that is not intended to change the market place, but is aimed at lowering the risk to the contract. The specification applies to the material that actually goes on the road. It specifies fundamental material properties that predict performance with respect to traffic and within the New Zealand temperature range. In New Zealand the NZTA penetration based NZTA M1 specification worked well while the crude source and processing was fixed. However with the increased use of imports and changes in the method of manufacture of 40-50 grades at Refining NZ, issues have arisen in performance of blended bitumen grades particularly in asphalt grades. That is, the bitumen does not have the required rheology to perform in some circumstances. The industry generally adopted rheological testing in 2007, particularly using Dynamic Shear Rheometer (DSR). Data collected in New Zealand from numerous unique bitumen sources has led to the establishment of a bitumen library by Fulton Hogan that allows samples from the early 2000s to present day to be tested using these techniques. The use of performance based mix design that includes deformation and fatigue type testing has allowed the rheological effects of these changes to be studied in mixes. Correlation with field performance has also been carried out. The outcome is a specification based on fundamental rheological testing as used and validated in USA (over 20 plus years) that applies to New Zealand conditions and practices.


  • English

Media Info

  • Pagination: 22p
  • Monograph Title: Industry collaboration: success, barriers and future development: 15th Annual Conference, Rydges, Queenstown, 2-4 November 2014

Subject/Index Terms

Filing Info

  • Accession Number: 01573410
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Aug 24 2015 2:11PM