A trial testing the use of crumb rubber asphalt on highly trafficked roads has won the Sustainable Transport Infrastructure Award at this year’s National Transport Research Awards.
Tyre Stewardship Australia (TSA) has opened expressions of interest for funding to help local councils and other eligible organisations utilise crumb rubber (CR) in low traffic asphalt roads.
Crumb rubber asphalt is being laid on a busy Melbourne road as part of a new trial funded by Tyre Stewardship Australia (TSA), the Australian Road Research Board (ARRB) and the Victorian Department of Transport.
While already a proven technology on country roads, the project aims to increase opportunities to use crumb rubber asphalt on highly trafficked roads.
The asphalt will be laid on a 1.4 kilometre section of East Boundary Rd in Bentleigh East, with four seperate crumb rubber mixes and two asphalt control sections. The equivalent of 1600 car tyres will be used.
The trial is in line with the Victorian Government’s Recycled First policy, which aims to increase the use of recycled materials in construction projects, TSA CEO Lina Goodman explained.
“Australia generates the equivalent of 56 million used car tyres every year. Around 30 per cent of those end up in landfill or are stockpiled,” she said.
“Finding innovative and sustainable ways of using old tyres is vital, and crumb rubber asphalt roads are the perfect solution to a waste problem.”
According to ARRB CEO Michael Caltabiano, when added to an asphalt mix, crumb tyre rubber not only assists with the reuse of waste, but adds value to the road structure.
“ARRB’s applied research findings show that crumb rubber asphalt lasts longer, performs better and delivers a better economic outcome for the community,” he said.
Lab and field testing will be conducted at regular intervals, with a final report due by mid 2022.
Logan City Council has teamed up with Tyre Stewardship Australia (TSA) to trial a new eco-friendly road surface.
The surface is a combination of old tyres and reclaimed asphalt, and will be installed on Lagoon Road, Carbrook over the next month.
TSA has committed $150,000 to the trial and additional lab testing, which aims to prove the new surface will be as good as, or better than, standard road sealing.
Logan City Council Road Water Infrastructure Director Daryl Ross said council is always looking at innovative ways to deliver better roads.
“Council wants to build a road network that is suitable for our growing region,” he said.
“This partnership with TSA aims to enhance road quality for users in a cost-effective way.”
According to TSA CEO Lina Goodman, the trial is about creating a recycled road product that saves money, while delivering a safe and reliable product.
“It also has a huge environmental benefit to the community because it is using recycled tyres,” she said.
Crumb rubber is produced by reducing scrap tyres down to their basic materials and removing steel and fibre, along with any other contaminants such as dust, glass or rock. Reclaimed asphalt consists of old, damaged pavement materials milled and crushed into a new mixture.
According to a TSA statement, Australia generated the equivalent of 56 million used car tyres in the last financial year.
“Eighty-nine percent of them were recovered for reuse or processed into tyre derived products. The rest ended up in landfill or were stockpiled,” the statement reads.
“In Queensland, the equivalent of 12.7 million car tyres were generated with a similar recovery rate of 69 per cent. Around 14 per cent of the recovered tyres were locally recycled into crumb rubber and granules.”
The trial will begin in May, with initial results expected in August. Queensland civil infrastructure firm Fulton Hogan will construct the road.
Tyre Stewardship Australia hosted a workshop with stakeholders from across the whole supply chain, providing an update on the progress of crumb rubber uptake.
The circular economy is a long-discussed topic as multiple industries recognise the need to shift from the linear economy to one where products are kept in the supply chain for as long as possible.
While the term has been thrown around loosely from time to time, the roads sector is one that has been taking proactive action on material reuse for decades. Turning discussion into action, the Australian Asphalt Pavement Association (AAPA), which represents more than 500 members in the road construction sector, chose to embed this theme into its 18th conference.
Crumb rubber (CR) products are one of the best known and well tested areas that demonstrate the circular economy. CR modified binder has been used in Australia since the mid-70s, although its utilisation has been inconsistent and more common in spray sealing applications.
But in recent times, a more diverse use of CR in pavements has become commonplace through research and development funded by Tyre Stewardship Australia (TSA).
To get a sense of CR uptake, TSA sponsored a workshop at the AAPA Conference in Sydney in August.
The workshop was facilitated Joe Grobler from the Australian Road Research Board and included presentations from TSA Senior Strategy Manager Liam O’Keefe, Puma Bitumen’s Erik Denneman, Tyrecycle’s Clinton Habner and Fulton Hogan’s Darryl Byrne.
The presenters included stakeholders from each end of the supply chain of Australian tyre-derived product in the road sector, from bitumen supply to tyre recycling and road construction.
Mr Habner spoke on behalf of the challenges facing recycling industries that remanufacture end-of-life materials and the benefits that ongoing procurement of their product can provide to the sector.
Mr Denneman discussed the fact that increasing demand from CR binders is already impacting Puma Bitumen – one of Australia’s largest bitumen providers for asphalt products. According to Mr Denneman, we’re no longer waiting for the market to shift – it’s already moving. He also provided extensive technical analysis on trends in the industry.
Finally, Mr Byrne from Fulton Hogan spoke of the fact that as a contractor, he’s seen the benefits of CR binders in creating longer lasting pavements. He explained that the days of trials and demonstrations must give way to normalising use. Contractors are ready to provide the product, however, better manufacturing infrastructure that can accommodate CR and more cost competitive feedstock is required.
“We’ve got about 450,000 tonnes of tyre waste here in Australia. We use a small percentage of that, 10,000 tonnes in bitumen surfacing, [and] I think we can grow that quite rapidly over the coming years, with the aspiration within industry in various forms to get it to 35,000 tonnes per annum,” Mr Byrne said.
The panellists noted that an uplift in volume in CR is starting to occur in asphalt use as modern asphalt plants are able to produce wet mixed CR asphalts though vertical tanks with agitation.
Mr Byrne highlighted that an increase in CR consumption will require investment in equipment and new technology due to a limited number of producers on the market.
As the workshop arrived at the interactive component of the presentation, an audience of road owners/government, contractors, designers, binder suppliers, industry organisations and others were able to vote on a range of questions. More than 60 participants were involved in most questions with road owners/government making up around 40 per cent of the audience, followed by contractors and binder suppliers.
A majority of participants voted that performance drove their product selection followed by initial costs, whole-of-life costs, sustainability and policy. More than 80 per cent of participants are currently using CR, while the barriers stopping its increased uptake were attributed to a lack of infrastructure/supply, followed by a lack of specifications/guidelines and cost.
Around 63 per cent of participants believe adequate specifications/guidelines are not in place and around 40 per cent were unaware if their companies test CR for compliance with the specifications. Around 80 per cent of participants agreed sourcing local tyres was important to them.
Broadly speaking, the main barriers to increasing CR were noted to be cost, health and safety and performance.
Mr Byrne said that road agencies are increasingly changing their practices and predicts an increase in CR in other states and territories akin to how it has been used in Victoria.
One of the key discussion points was that CR has been used in Australia for more than 50 years and it was important all stakeholders stopped referring to these projects as “trials”. While VicRoads has been an industry leader in CR, a need to utilise more passenger tyres and shift the policy in government towards supporting local product manufacture was acknowledged.
In terms of modern specifications, the various states and territories each have their own specifications that support CR uptake and most require they be natural, synthetic and free from contaminants.
Mr O’Keefe said that the conversation reiterated that the industry is primed to provide the product to market, but it’s now the role of end users to “take up the challenge” and procure CR product in greater volume.
A crumb rubber asphalt trial will soon begin in Melbourne, with funding from Tyre Stewardship Australia (TSA) and the Australian Road Research Board (ARRB).
According to TSA CEO Lina Goodman, while crumb rubber is routinely used in rural road surfacing in Victoria, more testing is needed on highly trafficked roads.
“The aim of this project is to increase the opportunity to use crumb rubber in metropolitan roads,” Ms Goodman said.
“This trial is a landmark opportunity in the development of the circular economy in Australia.”
ARRB will trial a range of asphalt mixes and monitor performance over time.
ARRB Senior Professional Leader Melissa Lyons said the trial is a first of its kind in regard to scale and number of testing mixes.
“ARRB is proud to be a supporting partner of this project, which is about finding sustainable solutions to Australia’s tyre problem,” Ms Lyons said.
The crumb rubber asphalt will be laid on a 1.5 kilometre southbound East Boundary Road carriageway, between Centre Road and South Road in Bentleigh East.
Lab and field testing will be conducted at regular intervals, with a final report due by mid 2022.
A further six local government authorities have received Tyre Stewardship Australia (TSA) accreditation, after using tyre-derived raw materials in infrastructure projects.
The six new local governments are Burdekin Shire Council (QLD), Campbelltown City Council (SA), Launceston Shire Council (TAS), Paroo Shire Council (QLD), Prospect City Council (SA) and Upper Hunter Shire (NSW).
TSA CEO Lina Goodman said having local authorities on board was a vital step towards ensuring the sustainable management of old tyres.
Ms Goodman also noted having more councils on board would help drive the commercial viability of developing new and improved tyre-derived products.
“Along with transport companies, local governments deploy significant fleets of vehicles,” Ms Goodman said.
“Ensuring that the tyre needs of those fleets are catered for only by entities committed to responsible end-of-life tyre management can make a significant impact on sustainable outcomes for the over 56 million end-of-life tyres Australia generates every year.”
According to Ms Goodman, all newly TSA accredited councils will be closely watching crumbed-rubber asphalt trials in South Australia’s City of Mitcham, with a view off specifying the use of similar surfaces for their future road maintenance and enhancement projects.
“Crumbed-rubber asphalt has been in extensive use overseas, in climatic conditions similar to Australia, with long term use in California, Arizona and South Africa delivering excellent road performance results and highly desirable sustainability outcomes,” Ms Goodman said.
“The local road trial will be looking at a range of performance factors, such as cracking, rutting, moisture retention and general durability.”
Ms Goodman said all local authorities have the opportunity to use recycled tyre-derived materials in urban infrastructure, through both well-established applications and rapidly emerging new products.
“Existing uses of tyre derived material, for applications such as providing soft fall surfaces on playgrounds, are being added to by innovations such as erosion protection wall systems in waterways, noise barriers along roads and permeable pavements for carparks, footpaths and walking tracks,” Ms Goodman said.
“A major focus for the development of new materials is the continual improvement and tailoring of crumbed-rubber asphalt used in roads.”
New national specifications for Crumbed Rubber Modified (CRM) asphalt could see millions of waste tyres being used in Australia’s road infrastructure.
The Australian Asphalt Pavement Association (AAPA), Tyre Stewardship Australia (TSA), Main Roads Queensland, Main Roads WA, Sustainability Victoria and the Australian Road Research Board have worked together to develop and analyse research and development data to achieve cohesive national standards.
The new national specifications could see nearly 10 per cent of the accessible feedstock for Australian tyre-derived crumb rubber used in domestic road manufacturing, which adds up to almost 4 million end-of-life tyres every year.
The document was published by the AAPA national technology and leadership committee to facilitate the construction of demonstration trials of CRM gap graded asphalt (GGA), and to promote the use of CRM open graded asphalt in Australia.
The crumb rubber binder technology is based on the technology used in the US, with the first demonstration section of CRM GGA in the Gold Coast placed in late June.
CRM Asphalt can offer better drainage, reduced noise, improved rut and crack resistance and reduced maintenance cycles.
Engineers and road contractors are now able to work within parameters of the new national specifications to take advantage of CRM asphalt and spray seal.
TSA Market Development Manager Liam O’Keefe said reaching a national standard has been a critical part of increasing the potential market for crumb rubber use in Australian roads.
“To fully realise this potential for that use we must continue to work with industry partners to ensure the delivery of better roads and better environmental outcomes for all,” Mr O’Keefe said.
“The important next phase of the task is ensuring that the new specifications are used. As utilisation of the new specifications grows, so too will the benefits to the end- of-life tyre industry.”
AAPA Director of Technology and Leadership Erik Denneman said this is a great outcome that has come from the close collaboration between industry and road agencies in Australia.
“For AAPA this initiative fits our objective of encouraging the efficient use of available resources and promoting the use of sustainable products,” Mr Denneman said.
The new national specifications can be found here.
Tyre recycler Tyrecycle explains the benefits of using domestic crumb rubber product in road infrastructure, creating a circular economy and the growth opportunities available for the Australian market.