CarbonCure concrete trialled at Heidelberg Materials' plant
The Greenwich plant is injecting CO₂ into ready-mixed concrete for the first time in England.
The company is trialling technology that can reduce the CO2 emissions associated with concrete by around 7-11kg/m3.
The process involves injecting pure manufactured CO2 into fresh concrete, where it becomes permanently mineralised. This makes hydration more efficient, delivering stronger concrete and permanently locking in CO2. It also allows producers to use an average of 5% less cement within the concrete mix.
The process was developed over a decade ago in Canada and is gaining traction globally.
In addition, the company has announced the addition of calcined clay to its product portfolio. Calcined clay is suitable for use in cement production and involves heating raw clay minerals to between 650°C and 950°C.
The resulting calcined clay can be used to reduce the proportion of traditional clinker in cement.
CO2 emissions from clay calcination are significantly lower than emissions from clinker production. Thus, it is possible to achieve cements with CO2 emissions up to 40% lower than traditional cement.
