Concrete without CO2: can our biggest building material go green?

Concrete is strong and durable – which is why it’s the basis for so
much of our infrastructure. It’s also terrible for the planet, due
to one key ingredient: cement, which is responsible for almost 90%
of concrete emissions. Researchers have now found a way to recover
old cement while also reducing the environmental impact of
recycling steel. Madeleine Finlay speaks to Julian Allwood,
professor of engineering and the environment at the University Of
Cambridge, to find out how the process works, and what it could
mean for the emissions generated by the construction industry. Help
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