Thursday 25 October 2018

‘The battle to curb our appetite for concrete’

Earlier in the year, we posted 'New Exeter wonder invention to revolutionise building', about how researchers from the University of Exeter have developed a technique that incorporates graphene into concrete, "reducing the amount of materials required to make concrete by around 50% leading to a significant reduction of carbon emissions".

The extraction of sand and gravel and the production of cement have a huge environmental impact across the world. These are not just our words. According to this BBC article "The battle to curb our appetite for concrete":
We extract billions of tonnes of sand and gravel each year to make concrete for the building industry, and this is having an increasing environmental impact as beaches and river beds are stripped, warn campaigners.
Alongside this environmental damage, the building industry is also a major contributor to greenhouse gases - cement manufacturing alone accounts for 7% of global CO2 emissions.
Scientists are working to reduce the amount of raw materials used in the construction industry:
Bath University researchers say up to 10% of sand in concrete can be replaced by plastic without significantly affecting concrete's structural integrity - crucial in determining whether to use plastic in concrete for buildings.
"There's a serious issue with plastic waste. Anything we can do to address this and find alternatives to putting plastic in landfill is welcome," says Dr Richard Ball, of Bath University's architecture and civil engineering department.

3D printing could also help:
“We could cut up to 40% of the concrete we use, and that would have a huge impact on the sand we are using. There's no penalty for over-design, and so designers and engineers will understandably err on the side of safety," says Dr John Orr of Cambridge University's engineering department - in case those constructing the building are tempted to cut corners. One way of stopping this could be by 3D printing buildings, creating concrete shapes directly from an architect's design.