Glass from jars has become a key ingredient in the recycled bitumen mix being used to revitalise New South Wales roads.
A program that begun in 2021 has now reached the heart of Sydney, with a section of the busy Clarence Street in the central business district now getting the glass-jar treatment.
The glass is only a tiny percentage of the bitumen mix, but makes a significant contribution to the recycling, according to the City of Sydney.
“It’s a good replacement for sand in the mix. It works as well as sand and gives us a circular economy outcome,” a spokesperson for the city, Andrew Booth, told CarExpert.
It is also a way to prevent some glass going to landfill, as there are a variety of reasons – broken items, coloured glass, contaminated glass – why some old glass cannot be recycled into new glass.
But it’s not just glass in the bitumen mix, as the material used in Sydney is also made partly from old roads.
“The glass is about 2.5 per cent of the allowable content in the asphalt mix. Coupled with some reclaimed asphalt, it makes up about a quarter of the materials for the road,” Booth said.
The latest Sydney work is only for a one-kilometre stretch of Clarence Street, but it took around 120,000 recycled glass jars and more than 200 tonnes of reclaimed asphalt.
The latest work takes the glass jar total to more than 1.5 million in little more than two years, with 6000 tonnes of reclaimed asphalt included in the road renewal.
The council has also used other materials for its road works, including crumbed rubber, printer toner, and soft plastics.
The Clarence Street project uses densely-graded asphalt to meet standards set by Transport for NSW for heavy duty traffic operations.
“Clarence Street’s renewal is a fantastic sustainability outcome. When we use this mix it saves money, is better for the environment and reduces what ends up in landfill,” the Lord Mayor, Clover Moore, said.
“What was once considered waste is now being seen as a resource. The City of Sydney resurfaces around 35,000 square metres of road each year. By favouring more sustainable materials we can continue to ensure long-term benefits.”
Picture credit: City of Sydney/Abril Felman