Every year, Australia is producing a whopping 67 million tonnes of waste with only 37 per cent being recycled. Not only that, but the road construction sector also uses eight tonnes of quarried materials including sand, rock and gravel per person every year, making 200 million tonnes in total, according to Cement Concrete and Aggregates Australia.
Waste and improper recycling are big problems in Australia, but change is starting with sustainable road construction underway in many states and territories. Of course, there are a range of factors to consider to ensure the success of recycled road projects, which is why there are a few government bodies involved to enforce specifications and safety standards.
AUS-SPEC, the national local government specification system, managed by NATSEC in conjunction with IPWEA, is working to reduce waste sent to landfill by using recycled materials in Australian roads. They’re also creating specifications to ensure uniform use of recycled materials in roadworks. And, the response to the first phase of their project was very positive, with more than 65 responses received from councils offering experienced advice when using recycled materials in roadworks.
This is a step in the right direction for the industry, and having a system body involved will help ensure accessibility to recycled road materials across rural and metropolitan areas. But what materials will be used and how will this impact future road making and equipment?
Recycled Road Construction Materials
Recycled road base uses a range of different materials to create an alternative asphalt mix. These materials can include: crushed concrete, recycled asphalt, plastic bags, recycled plastics, printer waste toner and cartridges, glass, and crumb rubber (recycled old tyres).
As part of a worldwide movement to improve recycling, Australia has started to produce roads using recycled plastics, glass and crumb rubber. Most notably the first Australian road made entirely out of recycled materials opened in central Adelaide in February of 2020. The road is made from reclaimed asphalt pavers and vegetable oil from local producers which is believed to be 25 per cent stronger than standard asphalt.
The use of recycled plastic in road bases has also been trialled in other states including Queensland, Tasmania and New South Wales. Victoria also trialled a new road base product on a Melbourne road in May of 2019. According to the Australian Government Department of Agriculture, Water and the Environment, roughly 200,000 plastic bags and packaging, 63,000 glass bottles, toner from 4,500 used printer cartridges and 50 tonnes recycled asphalt were used to build the road.
Since construction, research suggests that the Victorian road made from soft plastics, glass and toner has a high resistance to deformation and fatigue, making it more durable with higher longevity than regular asphalt. Previously, Australia has used anywhere from 10 to 75 per cent of reclaimed asphalt pavements and recycled materials in road construction. But now, it appears there are alternative ways forward to increase the amount of recycled products in road base products without compromising on quality.
By using recycled road base and materials in road construction, Australia could certainly reuse more of the 67 million tonnes of waste being produced, while lowering greenhouse gas emissions and improving the rate of recycling.
Recycled Road Construction and Road Making Machinery
In order to change the way Australia makes its roads, there will likely be some disruption to the road making machinery currently used. It’s believed that more sustainable technology could be adopted to ensure the longevity of road making machinery.
Machines4U founder, Steve Krebs, believes that the push towards sustainable road making is a big positive for the industry and Australia as a whole.
“The area of road making equipment has gone through a lot of change in the last decade, and one particular change that has been very interesting is the increase in demand for road reclaimers, which are a very cool loader attachment,” says Krebs
“Making the move to sustainable road making will certainly help to reduce the waste that ends up in our [Australia’s] landfill. With so much waste created each year, it’s great to see the industry recycling more and using those recycled materials in the construction industry. This is a positive step toward creating a circular economy.
“As far as road making machinery is concerned, more sustainable technology may need to be introduced in order to improve the current spray and spreader machines. Different materials will require different spreading and spraying to ensure they are laid correctly without compromising on safety and longevity,” Krebs adds.
Improvements to Australia’s Waste Problem
The introduction of road base using recycled plastics, glass and cartridges will make a significant impact on reducing Australia’s waste, and will contribute to a circular economy. Since new construction materials are becoming harder to come by and waste is stockpiling, making roads from recycled materials is a step in the right direction.
But, in order to implement the changes to the industry, local governments and councils will need to partner with economic, social and environmental leaders to ensure a positive outcome for all. The Australian flexible Pavement Association (AfPA) is committed to improving environmental, safety and health standards in Australia’s paving sector with a 5-year strategy in place.
Asphalt contractor Austek has also made moves to a more sustainable future by purchasing the Benninghoven ECO3000 asphalt plant to aid in the mixing of tyre derived recycled materials. These are just a couple of examples of those within the industry making changes to ensure they are moving toward a sustainable future of road making.