Research from Western Sydney University has made another stride in using recycled materials for aggregates, a key obstacle for engineers to develop a circular economy for construction.
Professor Vivian Tam from the University’s School of Engineering, Design and Built Environment said her method had the potential to return waste concrete back into its original form.
“My research looks into how waste concrete can go from being recycled into low-grade aggregate to instead being made as strong as virgin concrete,” Tam told create.
While not formally endorsed in the industry, Tam’s method involves pressuring the waste material and injecting carbon dioxide to increase strength and reduce water absorption.
Her “CO2 Concrete” could benefit the construction sector by $16 billion while saving more than two billion kilograms of carbon dioxide emissions.
With such benefits, one might see this solution as a no-brainer. But the industry and government is yet to step into the unknown and trial the product.
“Engineers are reluctant to be the first to use the CO2 Concrete,” Tam said.
“Part of the problem is perceived risk, and part is the government not pushing projects to use it. In Japan, for example, the government says industry has to use more recycled materials on projects of certain sizes. That drives innovation.”
The importance of developing a circular economy of construction materials was recently emphasised by Holcim and Bloomberg as the companies formed a partnership to advocate for the system.
The partnership will allow Holcim to understand the barriers to achieving a truly circular economy in urban construction, with the help of Bloomberg, researchers and investors.
Holcim chief executive officer Jan Jenisch said the benefits to a circular economy were apparent on multiple levels.
A circular city is many things. They are powered by renewable energy, they’re connected by green mobility, they’re built with smart buildings with nature inside and much more,” he said.
“With Bloomberg, we want to go deeper in our understanding of what makes a city circular, what levers are at play, what works best, what can be replicated and what kind of bottlenecks are in the way.
“By better understanding the fabric of a circular city, we can empower more circular living so that we can all play our part.”
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