Crumb rubber gathering: Tyre Stewardship Australia

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.

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Millions of tyres could soon be used in Australia’s 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.

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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.

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