1/ Today’s production of concrete and cement generates large emissions of carbon dioxide. One way to reduce the climate impact of cement is to take advantage of the material’s natural ability to capture carbon dioxide through carbonation. It is a natural process that can be enhanced by the smart design of concrete structures.
2/ Did you know? Carbonation is a natural process where carbon dioxide emitted from the limestone in the production of cement is reabsorbed. When cement is used as a binder in concrete, the concrete absorbs carbon dioxide from the air over the entire lifetime of the concrete, i.e. the cement undergoes carbonation.
3/ What does this mean? Bridges, buildings and other concrete structures reabsorb and convert the concrete into limestone. This has long been considered problematic since it also means the material erodes, but in light of climate change, the ability to bind large amounts of carbon dioxide through carbonation can also be seen as beneficial.
4/ Over its lifetime, concrete structures absorb 50% of the CO2 emitted during cement production (as per latest IPCC report). This demonstrates the chemical reactivity of cement-based materials and can be incredibly important.
5/ When designing structures, it’s also important to understand how carbonation works. The material must be reactive, which means it’s important in the design process to leave surfaces open so that they can absorb carbon dioxide from the air.
Source: Katarina Malaga from RISE Research Institutes of Sweden
Global Carbon Project: GCP - Carbon Budget
Read here: How concrete can become a carbon sink | RISE