Could we replace cement as the vital element in concrete some day? We look at two alternative answers to this question.
The Problems with Cement
Portland cement dominates in the construction and road building industries. From an environmental point of view, cement is not the perfect solution. The cement industry accounts up to 7% of the world’s carbon dioxide emissions. For every 600 kg of cement, approximately 400 kg of CO2 is released into the atmosphere.
It is possible to recycle concrete by crushing it and using the gravel e.g. in road construction. However, the demand for new concrete is huge and increasing. According to The Washington Post, China used more cement between 2011 and 2013 than the U.S. used in the entire 20th Century. The worldwide production of cement has increased from 3.3 billion tons in 2010 to 4.2 in 2016. Even that is not enough; shortage of cement is a real problem in some countries.