Concrete is a serious greenhouse gas problem? Maybe not for long
I never thought about it, but making the components for concrete is a large contributor to greenhouse gas emissions. I know! Shocking! A News.com piece opened my eyes to this problem:
As a result, Ulm and Constantinides believe that it may be possible to make concrete out of different materials and processes. Concrete is currently made by heating limestone (calcium, carbon and oxygen) and clay (silicon, aluminum and other materials) to high temperatures (1,500 degrees Celsius). The process generates significant amounts of carbon dioxide.
Replacing the calcium from limestone with another material such as magnesium could conceivably lead to lower processing temperatures, and thus lower greenhouse gas emissions. Indirectly, it could also ease recycling and disposal costs. Now, industrial concerns pay to get rid of magnesium.
Wow. Okay the big issue is, however, making sure any replacement for the centuries old recipe for concrete (we have the Romans to thank for it) will still be as strong as the current one.
When I first read the headline I was hoping they had found a recipe for concrete that absorbed CO2 from the atmosphere as part of the curing process (yes, concrete doesn’t "dry" but "cure" … it’s a chemical reaction, hence wny concrete sets under water). Oh well, maybe that will be the next breakthrough.
Tags: concrete, greenhouse gases, CO2
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