Concrete Made from Carbon Dioxide for a More Sustainable Construction Industry

Since leaving the caves, human beings have needed to build houses and buildings where they can be indoors. The problem is that, over time, construction activity is affecting the most important house of them all: planet Earth. Today, cement production is responsible for one-tenth of annual human carbon dioxide emissions. Reducing this carbon footprint can therefore be a significant step forward in the fight against global warming. At UCLA (University of California, Los Angeles), they have already started to work and are developing a model that will allow this. Their goal is to create a "green" concrete, which they have named CO2Concrete, that uses the carbon dioxide emitted by the cement industry and other types of factories. How do they achieve this? By substituting the Portland cement ordinarily used to amalgamate the concrete with another ingredient. 

Usually, cement, sand, stone, and chemical additives are used to mix the concrete. The role of cement is to provide consistency to the mixture and give it the ability to set, i.e., solidify. What UCLA researchers have done is to use portlandite, a mineral rich in calcium hydroxide, which absorbs carbon dioxide and generates limestone, which is one of the components used in the production of cement. The process of solidification with this material is similar to that observed in the shells of mollusks.  

The team has managed to complete the process in a matter of hours, a factor of great importance for industrial production. Also, they point out that the reduction of the carbon footprint is between 50 and 70% less. Last but not least, this would be achieved with performance and price comparable to traditional concrete. In other words, a new concrete that is both affordable and sustainable.

Thanks to the public funds received, UCLA has already managed to produce one hundred tons of CO2Concrete within three months. The resulting concrete will be used in construction projects on the university campus, and the surplus will be donated to other projects.

New, more sustainable types of concrete

CO2Concrete joins a large number of innovative technological projects that are generating new types of more ecological concrete. Thus, some time ago, we talked about a kind of concrete that includes a mixture of carrots and beets or a new type of concrete made from desert sand. In addition to this, there are also initiatives to promote recycling in construction. All these new processes and improved materials will result in more sustainable construction that follows the circular economy's principles.

If you want to learn about more strategies for eco-friendly construction, you can also take a look at the article that we recently dedicated to the living bridges of India. These structures are based on time-honored techniques that some architects are recovering within a new discipline, baubotanik.

Source: Construction Dive