A council in Sydney is the latest to pave its roads with recycled glass, and is now working with other councils to start a group procurement.
Randwick Council, in partnership with the Downer Group, is trialling the use of recycled glass asphalt mix on three roads in Randwick and Maroubra.
The asphalt mix incorporates crushed glass from approximately 224,000 recycled glass bottles sourced from residential recycling bins, which was used a sand replacement in the asphalt.
City of Adelaide and Hume City Council in Melbourne have also used glass in recycled roads, while Sydney councils are experimenting with industrial waste and plastics.
Low demand for recycled glass
Randwick Council Coordinator of Engineering Steve Audet says the type of glass needed in road construction requires specific processing.
“The glass that’s needed for asphalt production requires a high heat process, and a process where there’s quite stringent design on how the asphalt is produced,” he told Government News.
The glass needs to be clean, and free of glue, paper and residual liquids.
“You can’t just get broken glass and go ‘we’ll put it in the road’. It’s actually a finely measured and manufactured product,” Mr Audet says.
“There’s a lot of quality control in the processing of it, but at the moment there’s not a lot of people that do it because there’s not a lot of demand out there.”
He is hoping for more councils to get on board to create an incentive for businesses to look at recycled glass.
“If you think how much asphalt each council does, if we could then combine that to be a quarter of Sydney’s asphalt, it starts to become attractive sort of numbers,” Mr Audet said.
Group procurement for recycled glass
Randwick is currently working with Southern Sydney Regional Organisation of Councils (SSROC), an association of councils in Sydney’s southern and eastern suburbs, CBD and inner west.
It is looking to start a large group procurement initiative with SSROC to create a demand for the industry to invest in recycled glass for roads.
“I believe all the general managers of all of the SSROC member councils have committed to looking at increasing the recycled content within construction materials,” Mr Audet said.
The three recycled glass road projects were paved on Evans Street in Randwick, Carter Lane in Randwick and Maroubra Road in Maroubra.
Minimal waste
Council ensured there was minimal wastage, reusing as much of the old materials from the roads as it could.
“When we take the surface off a road, that surface is not disposed of. It’s reprocessed and up to 30 per cent say of your new asphalt is old asphalt,” Mr Audet said.
When it comes to the safety and durability of the roads, he does not believe there are any concerns.
“It’s coarser, it’s got different colours to sand, but it has the same texture,” Mr Audet says.
“It’s not sharp, it’s crushed and its ground up and grated so it’s got the same quantity as the different sized particles in the same sands that we use for asphalt production.”
He says that using higher proportions of recycled glass in asphalt could affect road quality, but not in the quantities the Council is using in its trial.
Mr Audet says councils have the potential to create change because of the bulk quantities of materials they use.
“There’s opportunities to make a real difference by looking at some alternatives in that regard because of the quantities that we use,” he said.
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but the colour is so black! absorbs and re-radiates heat. When can we get light coloured road surfaces?