Discarded seashells turned into low-carbon concrete mix ingredient

Researchers at the University of East London have developed a sustainable method to reduce the carbon footprint of concrete by using discarded seashells, specifically scallop shells, as a partial replacement for cement. By grinding these calcium-rich shells into a fine powder, they can substitute up to one-third of the cement in concrete mixes. This innovation not only repurposes millions of tons of shell waste that would otherwise be discarded but also achieves a significant 36% reduction in carbon emissions associated with cement production, which is responsible for about 7% of global emissions. The shell powder enhances concrete performance by refining its pore structure, making it denser and less permeable, and actively participating in cement hydration to form additional binding compounds. This results in concrete that maintains most of its core structural properties even with moderate cement replacement. The research highlights the potential for this approach to be scaled industrially, offering a cost-effective, eco-friendly alternative that aligns with growing regulatory demands for lower carbon construction materials. Published in the journal Construction