A team of researchers from MIT discovered that adding an inexpensive ingredient to concrete can reduce the amount of carbon dioxide generated during concrete production.

Concreteosis, i.e., the contemporary “beauty” standard

Concrete, as the key ingredient in virtually every residential building, shopping center, office building, and most roads, serves as the architectural backbone of cities. It is estimated that up to 70 percent of the global population lives in buildings that are at least partially constructed with concrete. Despite its numerous benefits, concrete has serious consequences for both people and the environment, one of which is the intensification of the heat wave effect.
A city covered with concrete and asphalt absorbs solar radiation and subsequently releases it into the streets. Impermeable concrete or asphalt pavements constitute over 30 percent of most urban areas, and during the summer, they can reach temperatures as high as 60 degrees Celsius.

Concrete as a climate-friendly solution

Immediately following water, concrete is the second most commonly used material worldwide. Unfortunately, the cement industry contributes to approximately 5% to 10% of global carbon dioxide emissions, making it the third largest contributor to climate change, after coal-fired power plants and vehicles with internal combustion engines.

Production of concrete and carbon dioxide emissions

However, there is reason for cautious optimism due to a recent discovery by scientists. They have found that the addition of a relatively inexpensive and easily accessible ingredient to concrete has the potential to enhance its climate-friendliness.
Concrete is produced through the blending of cement with aggregates like stone and sand. The process of burning limestone, clay, and other substances in a furnace generates carbon dioxide. When the mineral mixture is subjected to heat, the calcium carbonate and clay undergo a transformation into clinker, simultaneously releasing carbon dioxide into the atmosphere. As a result, carbon dioxide in the atmosphere reacts with concrete, leading to its mineralization through a process known as carbonation.

Treating concrete with sodium bicarbonate

A team of researchers from MIT has developed a method to reduce carbon dioxide emissions during the initial stages of concrete production by incorporating sodium bicarbonate. This additive has the potential to decrease carbon dioxide emissions related to the early stages of the production process by up to 15 percent.

Quicker binding of concrete and environmental perspectives

The newly developed concrete exhibits accelerated binding, retaining its mechanical properties, thereby expediting construction projects. MIT’s invention suggests the potential for carbon sequestration during the early stages of concrete curing. The researchers assert that this technology can be combined with other advancements to create construction materials that are even more environmentally friendly. Ongoing research is being conducted to evaluate the long-term effectiveness of this concrete.

Miłosz Magrzyk