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Welcome to the September edition of the Austroads newsletter.

We are pleased to announce that abstracts are now being accepted for the 9th Austroads Bridge Conference which will be held in Sydney 22-24 October 2014. Submissions can be until Monday 30 September 2013. See the conference website for more details.

Maximising the Use of Reclaimed Asphalt Pavement

The use of reclaimed asphalt pavement (RAP) material in the production of new asphalt products has become standard practice, both internationally and locally. In many countries, including Australia, RAP is by far the most recycled construction waste product.

This report, published in August 2013,  presents the findings from the first year of a three year Austroads study which aims to maximise the re-use of RAP in new asphalt product. The objective of this first year of study is to improve the methodology for the characterisation of RAP binders and the design of the binder blend in asphalt mixes containing RAP.

The study included a literature survey of the current international state of practice in terms of RAP binder characterisation. It further included experiments to develop a more practical and cost-effective approach to characterising the properties of binder blends containing RAP. 

Test Methods for Sprayed Sealing Binders

For more than 40 years the durability performance of bitumen binders in sprayed seals has been assessed in Australia using an established laboratory test method known as the durability test (AS 2341.13: 1997). The durability test however has a number of issues including test equipment sustainability.

Australian practitioners identified an urgent need for a more robust test method that could replace the current method while maintaining its important functions.

This report, published in August 2013, presents the results of a literature review and laboratory study which was conducted as part of the development of a new-long term ageing (durability) test.

The literature review of existing low-temperature binder characterisation tests identified a number of test methods that were suitable for use as part of the new durability test method.

Preliminary experimental investigations were conducted to assess the ability of the tests selected during the literature review to characterise the properties of aged bitumen and polymer modified binders. Two methods known as the dynamic shear rheometer (DSR) flow test and the extensiometer critical tip opening displacement (CTOD) test were identified as being the most appropriate for future use.

It has been proposed that further research work be conducted using these two test methods to determine which is most suitable for use in a future long-term ageing test method.

A Focus on Road Design

The Austroads Guide to Road Design is a primary reference for Australian and New Zealand road designers.  In the past 12 months more than 30,000 copies have been downloaded. 

The Guide content is managed by the Austroads Road Design Task Force which has representatives from all Australian and New Zealand road agencies.

The Guide captures the contemporary road design practice of Austroads member organisations and provides valuable guidance to designers in the production of safe, economical and efficient road designs.

The Guide provides information and advice on:

  • road design process
  • the philosophy and principles of good road design
  • geometric design to ensure coordinated horizontal and vertical road alignments and appropriate cross-section standards are applied in road layouts
  • drainage design and practices to meet the requirements of local planning agencies
  • the treatment of roadside areas
  • the design of paths for pedestrians and bicycle riders
  • aspects of geotechnical investigations and earthworks design
  • documentation of road designs and their application to national standards.

Nine Guide parts are currently under review by the Task Force:

  • Part 1: Introduction to Road Design
  • Part 2: Design Considerations
  • Part 3: Geometric Design
  • Part 4: Intersections and Crossings - General
  • Part 4A: Unsignalised and signalised intersections
  • Part 4B: Roundabouts
  • Part 4C: Interchanges
  • Part 6: Roadside Design, Safety and Barriers
  • Part 6B: Roadside Environment

Comments on the Guide content and use is welcomed and should be directed to austroads@austroads.com.au.

In addition to the Guide updates the Task Force is coordinating research projects which examine:

  • the  performance of  measures used to gradually reduce vehicle speeds in high speed environments
  • the appropriate acceleration lengths for entrance ramps onto motorways
  • improvements in the current road design standards that will safely accommodate heavy vehicle movements
  • standardised road design drawing presentation
  • road design elements that contribute to crash occurrence and crash severity
  • the effectiveness and consistency across Australia and New Zealand of measures to alert drivers to the dangers of crossing floodways when under water.

Upcoming Workshops and Conferences

Drainage Design Webinar– An Overview of the Austroads Guide to Drainage Design
17 September 2013, Online

NEW Austroads Turning Templates Webinar - A Beginners Guide
19 September 2013, Online

2013 Flexible Pavements Conference
22-25 September 2013, Brisbane, Australia

36th Australasian Transport Research Forum
2-4 October 2013, Brisbane, Australia

NEW Bike Futures Conference
16-18 October 2013, Melbourne, Australia

2013 Australasian College of Road Safety Conference | A Safe System: The Road Safety Discussion
6-8 November 2013, Adelaide, Australia

17th IRF World Meeting & Exhibition
9-13 November 2013, Riyadh, Saudi Arabia

Low Volume Roads Symposium
25-27 November 2013, Cairns, Australia

6th State of Australian Cities Conference
26-29 November 2013, Sydney, Australia

4th International Safer Roads Conference
18-21 May 2014, Cheltenham, UK 

NEW Velo City Global Cycling Conference
27-29 May 2014, Adelaide, Australia

NEW Austroads Bridge Conference
22-24 October 2014 Sydney
Abstract submissions close 30 September 2013

Diary dates

Austroads PMB spray seal trials webinar: 10 October 2013 online

ARRB Conference: 19-22 October 2014 Sydney