A revolutionary cement production process could slash the millions of tons of carbon emitted by Aussie construction sites every year.
It’s no secret that concrete is by far one of the most common construction materials used across the country.
Seen everywhere from iconic buildings like the Sydney Opera House to the thousands of Aussie homes dotting our coastlines, the industry is, on average, responsible for dishing out a whopping 29 million cubic meters of concrete and 12.5 million tonnes of cement every year.
But there’s only one problem – where there’s cement, there’s CO2 emissions.
It’s estimated that cement production is responsible for over 4.7 million tonnes of CO being dumped into the atmosphere every year, with 60 per cent of those emissions coming from the mixing process alone.
With the nation staring down a net zero target of 2050, the industry has spent years unsuccessfully scrambling for a solid green solution to the material responsible for the very building blocks of the nation – until now.
This week, a research team form Cambridge University claimed they had cracked the case, pioneering a method that tweaks an existing process for steel manufacturing to produce recycled cement without the nasty CO2 byproduct.
The discovery, published in the journal Nature, could provoke “an absolutely massive change” by providing low-cost and low-emission cement at scale, said Professor Julian Allwood, who co-authored the research.
“It is an extremely exciting project… I think it’s going to have a huge impact.”
According to Allwood, by substituting a key ingredient in that process with old cement sourced from demolished buildings, the end result was recycled cement ready for use in concrete that would require “little change or additional cost” on the part of the business.
If powered by renewable energy, he said, these furnaces could hope to produce zero-emission concrete at scale.
“Once the electricity has no emissions, then our process would have no emissions,” Allwood said.
Despite researchers describing the innovation as an “absolute miracle”, Allwood said construction sites would still need to reduce the amount of cement and concrete we use in the built environment.
“Concrete is cheap, strong and can be made almost anywhere, but we just use far too much of it,” he said.
“We could dramatically reduce the amount of concrete we use without any reduction in safety, but there needs to be political will to make that happen.”
Yet some challenges lie ahead. The recycled cement process requires slightly hotter than traditional furnaces, which experts say will increase power costs, and will need to see the creation of a supply chain to handle waste cement.
Despite the concerns, the process has been scaling rapidly, and researchers say they could be producing one billion tonnes per year by 2050.
While researchers have dubbed the innovation an “absolute miracle”, Allwood still encouraged construction sites to reduce the amount of cement and concrete we use in the built environment.
“Concrete is cheap, strong and can be made almost anywhere, but we just use far too much of it,” he said.
“We could dramatically reduce the amount of concrete we use without any reduction in safety, but there needs to be political will to make that happen.”
