Wednesday, 5 May 2021
Austroads has published research undertaken to identify opportunities to improve the pavement rehabilitation and strengthening treatment design procedures included in Austroads Guide to Pavement Technology.
In 2019 a new procedure was introduced into the Guide to Pavement Technology Part 5: Pavement Evaluation and Treatment Design for determining the thicknesses of structural treatments used to rectify distress and structural deficiencies of an existing flexible pavement.
Ross Guppy, Austroads Transport Infrastructure Program Manager says the new mechanistic-empirical procedure was a significant improvement, but work is still needed.
“Improved pavement rehabilitation design approaches will support Austroads’ member organisations to deliver an improved road transport network across Australasia.”
“The evolution from the empirical methods to mechanistic‑empirical approaches provides a real advantage, allowing designs to be adjusted so that they perform well under future traffic and loading conditions. It also encourages the use of new materials, which is essential in these times of budget pressures and scarcity of raw materials,” Ross said.
Didier Bodin, Principal Pavement Research Engineer at ARRB Group said the report provides a comprehensive roadmap for future work.
The research identified two primary areas for improvement. This first is to develop processes that can characterise past and future fatigue damage of bound pavement materials. The second is to develop a method to design asphalt overlays against reflective cracking.
“The design procedure could be improved to support the design of treatments that inhibit fatigue cracking of existing pavement layers. To do that, we need to be able to identify the remaining fatigue life of bound materials in projects where there is no detectable cracking. This work could result in cost-effective treatment alternatives.”
“Fully quantifying the different causes of reflective cracking will support the development of performance-based specifications for asphalt mixes. It could also further promote the use of new mix designs including incorporating recycled material, such as crumb rubber,” Didier said.
Download the report: Strategy for an Improved Mechanistic empirical Flexible Pavement Treatment Design
Join us for an overview of the report presented by Dr Didier Bodin and Dr Geoff Jameson on Thursday, 24 June 2021, 1-2 pm AEST.
The main topics will include:
- methods to characterise past and future fatigue damage of existing bound pavement layers
- design method to quantify the extent of reflective cracking in treatment layers
- enhanced use of traffic speed deflectometer data.