Circular Economy

‘Greencrete’ trial a first for the Hunter

Crushed glass sand and recycled plastic strips have been used in a Hunter-first footpath construction project trialling environmentally sustainable materials.

Lake Macquarie City Council recently poured the ‘greencrete’ along a 30m stretch of footpath on Steel Street in Redhead, with plans to monitor its performance and condition in the months to come.

Rather than natural sand, 50 per cent of the fine aggregate used in greecrete was crushed glass sand. The mix also contained thin polypropylene strips made from 100 per cent recycled plastic, which helps reinforce the concrete and replace steel mesh traditionally used in concrete.

“These Australian-made materials close the loop on recycling, providing a practical end use for glass and plastic collected from kerbside recycling bins,” said Helen Plummer, manager asset management for Lake Macquarie.

“The Redhead works were the first time in the Hunter it had been used to replace sand for a concrete footpath.

“Greencrete supplier Redicrete conducted extensive testing on the concrete prior to it being poured and it is a case of so far, so good. But we will continue to monitor the footpath in coming months to see how it holds up to everyday wear and tear, and whether it cracks or wears differently to normal concrete.”

More than 5,000 tonnes of glass are collected from Lake Macquarie homes for recycling every year. A portion of this is sent to a processing plant on the Central Coast, where the glass is washed and crushed into a fine, smooth substance, similar in appearance and performance to natural sand.

“Council is committed to exploring new and innovative ways to create a more liveable, sustainable and environmentally friendly city,” Plummer concluded.

Council’s trial of crushed glass sand in civil works project kicked off last June, with tonnes of the material used in underground drainage pits.

The footpath construction project is part of council’s asset management program, which identified more than 700m of new footpath to be installed in Redhead in the 2018/19 financial year.