University of Sydney researchers have successfully poured sustainable cement pavement made from fly ash and recycled waste, such as ground glass and carbon dioxide.
The researchers worked alongside Delta Electricity, recycling company IQ Renew and construction materials and industrial minerals supplier Morgan Ash: an Adbri Company, to develop the technology.
Concrete production is an energy intensive process that involves dredging sand and aggregates, which contributes to erosion and environmental degradation.
The trial cement has saved 752 kilograms of sand from being dredged and 327 kilograms of carbon dioxide from being emitted.
Director of the Waste Transformation Research Hub and School of Chemical and Biomolecular Engineering researcher Professor Ali Abbas said the cement was designed to counteract the environmental impacts of traditional concrete production.
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“Traditional concrete production is energy and resource intensive, yet is one of the most common materials used by the construction industry,” Abbas said.
“We sought to create a less energy intensive solution that would have less impact on the environment using carbon-capture and beneficially reusing materials that would otherwise end up in landfill.”
Abbas said around 12 million tonnes of fly ash are produced each year in Australia. The green concrete aims to use this waste product as a cement replacement.
“Glass, on the other hand, has traditionally been an expensive and energy-intensive material to recycle,” Abbas said.
“Less than half of the 1.4 million tonnes of glass produced each year in Australia is recycled. When crushed, glass can replace both sand and aggregates in green concrete.
“We are also testing an algorithmic intelligence technique that adapts the concrete blend to specific applications.”
Gaseous carbon dioxide is also locked into the concrete in a stable mineral form, preventing it from entering the atmosphere.
The researchers said greater environmental benefits could be realised when implemented on a larger scale. They plan to install another two eco-pavements on campus with differing blends to continue their trial studies.
Over the next 12 months the team will continuously monitor the concrete’s performance, with the hope to later commercialise the technology and introduce it to the market as an alternative to traditional concrete.