Melbourne researchers working on how to incorporate waste glass into pre-fabricated concrete structures say they’re creating a product that is light, strong and cheaper than current construction methods.
Funded by Sustainability Victoria and the Australian Packaging Covenant, University of Melbourne researchers claim finely ground recycled glass in concrete is a viable replacement for sand and existing supplementary material like fly ash and ground-down slag from blast furnaces.
Project manager for the university’s recycled glass R&D project, Associate Professor Tuan Ngo, said using sustainable and cost-effective materials taken from the waste stream was viable.
“The next generation of prefabricated structures can benefit from Australia’s eco-friendly, prefabricated housing research which is striving to deliver breakthrough products to enable our housing industry to compete on a global stage,” Ngo said.
Sustainability Victoria’s acting CEO, Carl Muller, said funding research programs helped recover resources and find new uses for materials once considered ‘waste’.
“This work can create jobs and, most importantly, ensure the community has confidence that recovered materials have a future use,” Muller said.
Researcher Dr Ali Kashani said glass used in concrete can be ground down to particles of similar size to cement and fly ash, with the finest grades delivering the greatest strength and durability.
“In the short term, we are confident that adding glass to concrete will allow us to build strong, light and durable non-load bearing walls with a reasonably high portion of recycled glass. Our work has shown it has excellent sound, thermal insulation and fire-resistant characteristics.”
“We are looking forward to working with the cement and concrete industries and building standard regulators to prove the viability of using these products in traditional concrete structures.”
Damien Crough, founding director and board chair of PrefabAus, Australia’s peak body for the off-site construction industry, said upgrading building standards to allow glass in concrete would open doors.
“This is where the real opportunities lie. Existing concrete supplementary materials like fly ash and slag are becoming harder to get and more expensive,” Crough said.
“The cost of glass will be an attractive factor for industry as it is readily available and inexpensive being about a third of the cost of fine sand, or less.”
Glass can be reused almost indefinitely and while it is one of the oldest man made materials with a history going back more than 3,500 years, new uses are still being found.
The volatility of markets can affect how much glass can be re-used at any one timepotentially leading to stockpiling of material that people want to be recycled.
What the future looks like:
With rubber and plastic now used in road base Swinburne University researchers are investigating how glass and flexible plastics could also be added to the road base mix.
RMIT is looking at new processing methods to recycle glass into household items including kitchen bench-tops, floors, wall or roof tiles.
Adding glass to the panels reduces the greenhouse gas emissions generated in the concrete-making process and reduces the need to use virgin raw materials.
Monash University’s is looking at how flexible plastics can be used in railways sleepers.