Boral claims carbon capture milestone in recycled aggregate trial

Building products company Boral has claimed an Australian first, producing concrete incorporating recycled aggregates that  were “recarbonated” to store carbon dioxide from process emissions.

According to a statement from the company – which is owned by ASX-listed SGH – on Monday, it took reclaimed concrete aggregates from its Widemere recycling facility, which were then used “to capture and permanently store” carbon dioxide from flue gas produced by the Berrima Cement Works. 

The project then saw the resulting recarbonated aggregates replacing 50 per cent of natural coarse aggregates in Boral’s Envisia concrete mix. 

Commenting on a milestone that Boral said demonstrates a viable pathway for products using such carbon capture technology, the company’s Head of Sustainability and Innovation, Dr Ali Nezhad, said the project also displayed “the potential for a further reduction in the embodied carbon of concrete by replacing natural aggregates. 

“The success of our carbon capture pilot plant at Berrima further validates the potential of recarbonation and underscores the importance of its broader recognition.” 

Concrete recarbonation occurs over many years, when the material absorbs carbon dioxide through its service, life and end of life phases. At end of life, when structures containing concrete are demolished, the concrete is crushed into aggregates, and its “exposed surface increases, accelerating the recarbonation rate” added Boral in a statement. 

“The recarbonation process at Berrima CCS plant [accelerated] the natural carbonation of recycled aggregates by exposing them to controlled process conditions.”

Boral’s concrete field trial at its Maldon cement manufacturing facility was assisted by the federal government’s Carbon Capture, Use and Storage (CCUS) Development Fund.  

Picture: supplied

Further reading

Boral awarded $24.5 million grant for decarbonisation project at Berrima

Boral-led team investigates calcined clay in lower-carbon concrete

Boral cuts emissions by substituting coal with alternate fuels