Concrete and Carbon Dioxide

Carbon Dioxide

The process of making concrete begins with making cement. The process of making cement begins with limestone, heating it to temperatures over 1,000 degrees Fahrenheit. Heating limestone, however, causes a release of carbon dioxide into the atmosphere. Not only that, but whatever source was used to produce the heat – often fossil fuels – also sends carbon dioxide into the air. Because of this, many environmental groups are concerned with how much cement and concrete get manufactured and used each year. But there’s good news: concrete has the capability of reabsorbing carbon dioxide.

Details on Concrete Absorbing Carbon Dioxide

The manufacture of cement produces 0.9 pounds of carbon dioxide for every pound of cement. To put this in perspective, making a cubic yard of concrete (about 4000 pounds worth) produces as much carbon dioxide as using a microwave oven for a year. During the life of concrete pavement, however, a slab can absorb nearly 60% of the carbon dioxide released during its manufacture. This process is even referred to as carbonation. As carbon dioxide enters the pores of concrete, it reacts with the materials therein, converting it into other substances.

Originally, people thought that this carbonation process would make the concrete brittle over time. Studies have shown, however, that carbonated concrete is potentially more durable. Because of this, further studies are underway to determine how much carbon dioxide is measurably reabsorbed by concrete over its lifetime. A recent study by researchers at the California Institute of Technology estimated that between 1930 and 2013, cement has absorbed 16 gigatons of carbon dioxide! That’s more than 20% of the carbon soaked up by forests in recent decades.

Further Benefits of Concrete Carbonation

Some experiments intend to find out how best to utilize this feature of concrete. Current developments include injecting harvested carbon dioxide into a concrete mix. Once trapped within the concrete, the carbon dioxide stays there forever. Other manufacturers are focusing on “green concrete.” This process uses recycled concrete that is pulverized and reused in other concrete mixes as part of the ingredient base, thereby reducing the amount of new cement necessary.

The longer your concrete lasts, the more carbon dioxide it absorbs. Using epoxy coatings to protect your concrete makes sure it lasts as long as possible. If you would like to find out how to expand the life of your concrete with epoxy coatings, West Coast Epoxy is ready to show you. We’ll answer any questions you have on the concrete process and provide you with several options using the best epoxy coatings available. Give our office a call to schedule an appointment or use our online form to receive a free onsite consultation.

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