In a Queensland first, crumb rubber created from giant mining tyres has been used in a trial to resurface one of Queensland’s major highways, BHP reports.

The trial was a collaboration between the Queensland Department of Transport and Main Roads (TMR), BHP and the Australian Flexible Pavement Association, with the aim to investigate if a crumb rubber modified binder made from a 100% OTR mining tyre could be used to construct a spray seal for Queensland roads.

Two giant BHP mining tyres, each over 4 m high and weighing 4.2 t, were used in the trial.

Although OTR tyres make up to 25% of ‘end of life’ tyres in Australia each year, OTR tyres are only 4% of the tyre waste rubber that is recovered.

The recycling process started with cutting up the tyres to remove steel and fibres, followed by crushing and crumbing the rubber into crumb of a suitable size. The rubber crumb was then bagged ready for transport to the bitumen binder production site. The crumb was blended into the binder, which was then transported to its final destination for spraying onto the road surfacing.

One giant mining tyre, in this context, provides 3.55 t of crumb rubber, able to seal up to 3.5 km of rural highway, BHP says.

The Peak Downs Highway where the repaving process took place links the towns of Mackay and Clermont and is the main link between Queensland’s Whitsunday Coast and the Central West region of the state near Moranbah.

Acting BMA Asset President, Tim Day, said the collaborative approach provides the mining industry a sustainable way to reuse tyre waste that would otherwise end up in landfill.

“It will have a positive impact on the environment, as more than 6,000 tonnes of tyres can be used to seal roads,” Day said. “This is a great example of how the by-products of mining can be used to positively affect the local communities where we operate, and we look forward to exploring how we can now further expand this trial to other road surfaces around the country.”

Lydia Gentle, Manager – Portfolio Delivery at BHP, was at the forefront of the trial saying she’s proud of the final outcome.

“It was a fantastic collaboration between BHP, TMR and our industry partners, and marks an exciting start to a more sustainable future for our tyre waste,” Gentle said.

Since completion, the highway surfacing has performed very well in Central Queensland summer heat under the intense mining traffic and continues to be monitored, according to BHP.