The Economics of Materials Availability and Recycling report released by Austroads presents research into the use of recycled aggregates as a possible means of reducing the cost of road maintenance and construction.
The report provides an estimate of the financial cost savings of incorporating recycled aggregates into pavement bases, and sets out the environmental and social considerations associated with recycling and resource use.
Austroads, which is based in Sydney, is the association for the Australasian road transport and traffic agencies.
Austroads assets program manager David Darwin told Quarry that the research had been conducted in response to the decreasing availability of road building aggregates from traditional sources such as quarries.
“Its aim was to document current practice and present two case studies to assist road agencies deliver services to their customers cost-effectively through the use of recycled aggregates where appropriate,” Darwin explained.
Austroads’ research was conducted over two years, gathering information to determine the degree to which there was a shortage in traditional pavement materials, as well as to find out what recycled materials and processes were currently available and the economics of using these in the longer term.
Two cases studies involving a local council in New South Wales and a construction and demolition recycling company in South Australia were also included in order to expand on the analysis on materials availability and recycling.
While the report estimated that the current supply of natural resources in most states would remain stable over the next 20 to 30 years, it stated that they were beginning to be exhausted, with haulage distances increasing and traditional sources becoming more restricted, partly due to heritage issues.
The report found that the application of recycled materials had been limited across Australia – with the possible exception of Victoria – and had mostly been used in areas of light traffic or where pavement performance expectations were lower. It was suggested that this was due to lack of certainty and confidence in the performance of recycled material compared with traditional materials.
With regards to financial benefits, the report stated that there was insufficient data suitable for a full economic analysis and extrapolated from information provided by VicRoads instead.
“This financial analysis was undertaken by extending the Sustainable Aggregates Tool to include the addition of up to a 15 per cent recycled component within pavement constructions Victoria-wide,” the report stated. “It was found that, on the basis of this assumption, there was an annual saving of approximately $24 million or a four per cent reduction in the total cost of pavement materials.”
According to VicRoads, potential savings of between 15 to 20 per cent could be achieved through use of recycled material in pavement.
Other long-term benefits mentioned in the report included reduced resource consumption, a smaller carbon footprint, diversion of waste materials from landfill, and more efficient use of traditional quarried materials for premium applications.
The full report can be accessed via www.austroads.com.au