Researchers at the University of Cambridge have pioneered a method to produce low-carbon concrete by recycling old cement using electric arc furnaces from the steel industry. This innovative process involves reactivating compounds in waste cement, significantly reducing the carbon emissions typically associated with cement production.
By leveraging electric-powered steel furnaces, the process not only addresses the chemical emissions from limestone conversion but also eliminates the need for high-heat kilns powered by fossil fuels.
Julian Allwood, a Cambridge academic, hailed this development as a "breakthrough for the construction industry," suggesting it could lead to the world's first zero-emissions cement when powered by renewable electricity. The team has formed Cambridge Electric Cement to commercialize their product, aiming to supply a third of the UK's cement needs within a decade. Initial tests have been successful, and a full industrial-scale trial is planned to assess scalability.
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The process works by crushing demolished concrete to extract cement, which is then used in place of lime as a flux in steel recycling. This generates high-quality Portland cement from the slag, expected to be as durable as conventional cement. This method stands out because it integrates seamlessly with existing industrial processes, equipment, and standards, offering a scalable and cost-effective solution.
However, Allwood emphasizes that while zero-emissions cement is a significant advancement, reducing overall concrete usage is also essential to address carbon emissions in construction. The detailed findings of this research are published in the journal Nature.
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Concrete remains a major contributor to global carbon emissions, making innovations like this critical for sustainable development.
