Crumb rubber gains traction to deliver Victoria’s busiest freeways

Old truck tyres are being used to upgrade Victoria’s busiest freeways for the first time ever, setting a new standard for the use of recycled materials.

Upgrades to the M80 and Monash freeways in Melbourne – delivered by Major Road Projects Victoria – have used 66 tonnes of crumb rubber, made of ground up truck tyres, as binder in asphalt.

The new binder is called Olexocrumb, developed by Puma Energy in Victoria. Olexocrumb is an elastomeric modifier for bitumen in roads that incorporates 10% recycled tyre rubber. Every tonne of binder includes the equivalent of 15 recycled passenger tyres.

The product’s use has prevented almost a thousand end-of-life tyres ending up in landfill or stockpiles.

An estimated 56 million passenger tyres reach end-of-life in Australia annually, with a quarter of these from Victoria. Up to a third end up in landfill or stockpiles. The 2021 export ban on whole tyres has further highlighted the need for more end markets.

While crumb rubber has been used for decades on country roads, this marks the first that it has been used as a polymer modified binder in open graded asphalt on a Victorian freeway.

The equivalent of 662 car tyres were included in the Olexocrumb binder on the M80 Freeway between Sydney Road and Edgars Road.

As part of the Monash Freeway Upgrade, the project installed 460 tonnes of asphalt containing Olexocrumb on the four lanes on the Eastlink bridge.

The Victorian Government’s ecologiQ program helped drive the use of crumb rubber on the M80 and Monash freeways, in line with its ambition to integrate as many recycled materials in transport projects as possible.

ecologiQ Director Tony Aloisio said these projects were an excellent way to demonstrate the use and viability of crumb rubber.

“This binder already meets existing specifications and can be used in any design with a polymer modified binder (PMB) in the asphalt – be it open graded asphalt or others such as stone mastic, gap or dense graded asphalt,” Mr Aloisio said.

“We encourage contractors to tap into these applications of recycled content that are approved but uncommon and blaze the trail for others.”

When used as a PMB in asphalt, crumb rubber adds flexibility, reduces surface cracking and improves longevity.

“Crumb rubber performs well, and we hope its use on these major freeways will help the industry shift towards seeing recycled products as the new normal,” said Mr Aloisio.

Puma Energy’s Global Head of Technology, Erik Denneman said Olexocrumb was created to give contractors a binder that is easy to use in conventional asphalt mix designs.

“Unlike other products, Olexocrumb has negligible residual rubber particles,” Mr Denneman said.

“The product complies with all the existing PMB specifications, making it easy and effective to use.”

Olexocrumb use of warm mix additives also allows asphalt to be produced at lower temperatures, reducing overall carbon emissions and fuming on site.

The future is green. The Victorian government is leading the charge to change the face of infrastructure delivery, building greener roads and rail and minimising waste across the industry.