Friday, 19 January 2018
Austroads' latest report proposes a national performance-based asphalt mix design specification that aims to take full advantage of current and emerging asphalt technologies.
Guide to Pavement Technology Part 4B: Asphalt recommends an approach to the design and characterisation of asphalt mixes in Australia and New Zealand. However, practice varies between road agencies and may not take full advantage of the enhanced performance characteristics that many new asphalt technologies can provide.
It is envisaged the framework would primarily be used for higher-end application and, at least initially, would not replace current specifications for routine works.
The performance properties proposed in the framework include workability, moisture sensitivity, rut resistance, modulus, fatigue resistance, permeability, resistance to ravelling and asphalt binder drain-off.
The report documents local and international asphalt mix design practice, with a focus on performance-based specifications.
A gap analysis identified elements in the Austroads mix design procedure requiring further research to develop a fully harmonised and performance-based asphalt mix design specification framework.
The report proposes further research to develop and implement the framework, including:
- a review of current sample preparation methods for laboratory testing
- harmonisation of test methods
- developing performance criteria for typical asphalt mixes
- establishing a better relationship between the Cooper Wheel Tracker test and field performance
- developing appropriate quality assurance/control guidelines for a fully performance-related specification.
Report link: National Performance-based Asphalt Specification Framework
Webinar: National Performance-based Asphalt Specification Framework
This webinar, presented on 27 February 2018, provides an overview of a project Austroads is undertaking to identify gaps in current practice for the performance characterisation of asphalt mixes. The ultimate aim is to develop a harmonised national performance-based asphalt specification framework that would take full advantage of the enhanced performance characteristics of current and emerging asphalt technologies. The webinar was presented by Joe Grobler. Download the presentation slides.