Modern civilization is pretty much made of concrete. People use more concrete than any other substance apart from water. But concrete is made from cement, and cement is the source of 10% of all carbon dioxide emissions worldwide.
Researchers at the University of Washington and Microsoft have developed a new kind of concrete made by mixing dried, powdered seaweed with cement. By fortifying cement with seaweed, the global warming potential of the concrete is reduced by 21% without weakening it.
This novel recipe for concrete was developed using machine learning models, arriving upon it in a fraction of the time it would have taken by traditional experimentation.
Producing cement leads to carbon emissions from the fossil fuels used to heat raw materials and from a chemical reaction called calcination that occurs during the production process. Seaweed is a carbon sink that pulls carbon dioxide out of the air and stores it while it grows. By replacing some of cement in concrete, the resultant product has a much smaller carbon footprint.
Machine learning was used to predict the ideal mixture of cement and seaweed to yield concrete with a reduced carbon footprint that still passed mechanical strength tests. Finding the right mixture would have taken 5 years ordinarily, but the machine learning process took only 28 days.
The researchers plan to generalize their work to different kinds of algae and even to food waste or other natural materials in order to create local, sustainable cement alternatives around the world.
**********
Web Links
Seaweed-infused cement could cut concrete’s carbon footprint
Photo, posted June 29, 2009, courtesy of Peter Castleton via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
Leave a Reply