A new blend of sustainable cement that uses a coal by-product has been developed and poured by the University of Sydney.
The cement mix includes fly ash left over from coal combustion and waste materials including ground glass and carbon dioxide.
In its trial, the cement was used for pavement and has saved 752 kilograms of sand from dredging and 327 kilograms of carbon dioxide emissions from being released into the atmosphere.
The energy-intensive process of concrete production was eliminated with the “green” method used, according to Professor Ali Abbas, researcher at the University of Sydney’s School of Chemical Biomolecular Engineering and director of the university’s waste transformation research hub.
“Traditional concrete production is energy- and resource-intensive, yet is one of the most common materials used by the construction industry,” Professor 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.
“Around 12 million tonnes of fly ash are produced each year in Australia. In our green concrete, we use fly ash as a cement replacement,” he added.
Abbas worked alongside Adbri company Morgan Ash, a construction materials and industrial minerals supplier, power company Delta Electricity and recycler iQ Renew during development.
It is hoped that the sustainable concrete technology will be eventually commercialised, taking advantage of the fly ash from New South Wales’ coal mines as part of the NSW resource recovery scheme.
The environmental benefits would be completely unlocked by implementing the aggregate to a larger scale project.
Two eco-pavements are planned for the University of Sydney campus using different blends as the trials of green concrete continue.