Date: Wednesday, 16 December 2020
Location: Online, 1:00 – 2:00pm AEDT
Organiser: Austroads
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The addition of a small amount of cementitious binder to non-standard granular materials may result in a fit for purpose base or subbase at a significantly lower cost than crushed rock complying with standard specifications. Such lightly bound cemented (LBC) materials have particular use in pavement rehabilitation and heavy patching as they are less susceptible to block cracking and crocodile cracking than cemented materials.
The binder content and strength of LBC materials are significantly lower than heavily bound cemented (HBC) materials. Austroads’ recent report, which reviewed the performance of selected Queensland pavements with LBC bases, has shown that it is possible to design and construct a low-strength material with base thickness and subbase support sufficient to limit the extent of the micro cracking development that leads to macro-cracking.
Considering the use and performance of LBC for moderate to heavily trafficked roads, a structural design method was developed for pavements containing LBC materials and HBC materials in the post fatigue cracking phase of life, including:
- A new elastic characterisation method, applicable to LBC materials and HBC materials in the fatigue cracked state, including methods to vary the design modulus according to the design modulus of the layer supporting the cracked material and the thickness and modulus of the overlying bound materials.
- Design charts to select LBC base thicknesses to inhibit the development of block cracking and crocodile cracking, with the minimum thickness varying with design traffic loading and the support provided by the layer under the LBC base.
This webinar will explain the structural design method in detail, including its development and application.
Presented by Dr Geoff Jameson, Dr James Grenfell and Phil Hunt.
There will be question and answer opportunities at the end of the session.
Dr Geoff Jameson is the Chief Technology Leader, Pavements at the Australian Road Research Board. He has over 30 years of experience in research and development in a wide variety of areas dealing with the design and analysis of pavement structures and the characterisation of pavement materials. Geoff is the author of various other parts of the Guide to Pavement Technology.
Dr James Grenfell is a Principal Professional at Australian Road Research Board (ARRB). He is currently working within Sustainability and Resilience having previously worked within pavement structures as part of Future Transport Infrastructure. James joined ARRB in February 2017. Much of his work has focused on Austroads projects, including looking at improving the knowledge of foamed bitumen stabilised pavements and the use of lightly cemented materials in pavement construction. James has a BEng degree and a PhD in Materials Engineering and has more than 16 years’ experience working on various projects related to pavement materials both in Australia and the UK.
Phil Hunt has spent 30 years working in the road design and construction industry. He has extensive experience in all-phases including concept, planning, design, construction, maintenance, works- programming, contract administration and asset management of roads and bridges. His work includes many gravel material investigations for both sealed and unsealed roads. Pavement performance is a keen area of interest, developing methodologies and tools to review a pavement’s performance based on condition data, construction history, maintenance costs and other factors.
No charge but registration is essential.
Can’t make the live session? Register and we’ll send you a link to the recording.