The production of the cement used in concrete is believed to be responsible for 5-8 percent of the global emissions of carbon dioxide but a new approach to making cement has potential to reduce both greenhouse gas emissions and water consumption.
The approach is being led by Professor Jason Weiss from the Oregon State University College of Engineering. He said it shows great potential for a type of cement that gains strength through carbonation, rather than the use of water.
“Instead of water reacting with cement, this carbonated cement reacts with carbon dioxide and calcium silicate,” said Weiss.
“This new product at first blush looks like conventional concrete, but it has properties that should make it last longer in some applications. In addition, use of it could reduce carbon dioxide emissions, which is an important goal of the cement industry.”
He said crude cement was used by the Egyptians to build the pyramids, improved during the time of the Roman Empire, and reached its modern form around 180 years ago. When used to make concrete – a combination of cement, sand and crushed rock - it’s one of the most proven building materials in human history.
However, this is actually part of the problem – concrete works so well, for so many uses, that 2-4 tonnes per year are produced for every person on Earth. It’s popular, plentiful, cost effective, and research is continuing to reduce its environmental impact. Production of the cement used in concrete is believed to be responsible for 5-8 percent of the global emissions of carbon dioxide, largely just because so much concrete is used.
“By using a type of cement that requires carbon dioxide to make, and in turn greatly extend the lifespan of some roads, the environmental benefits could be enormous,” Weiss said, noting that these products are just now being developed and tested.
He said some of the first uses of these products will be in pre-cast concrete products that can be created in a factory and transported to where they are needed. More ambitious and widespread use of the new approach may take longer.
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