Cement manufacturing accounts for around 7 percent of global CO2 emissions. Alternative types of cement use new ingredients, but the effects of these on performance are largely unexplored. A Swiss research institute hopes to remedy this.
Worldwide, around 12 cubic kilometers of concrete are produced per year, according to a press release from Empa, the Swiss material testing and research institute. It goes on to say that around 700 kilograms of CO2 are released per metric ton of cement produced, the main component of concrete. Overall, the CO2 emissions from the cement industry make up around 7 percent of total annual volume at this point in time.
Alternative types of cement and concrete should provide a remedy for this. One promising alternative is for example CSA cement made from calcium sulfoaluminate, Empa explains. Other alternatives use waste from other branches of industry such as slag from furnaces for crude iron extraction or from precious metal refining. Researchers from Empa are currently working on a magnesium-based cement that actually captures CO2 instead of releasing it like conventional building materials.
Empa states in the press release: “To ensure that such approaches do not end up as niche products, but can be produced industrially and cost-effectively, meticulous analyses must show that eco-cement meets the same requirements as conventional products.”
For this reason, the researchers are analyzing new mixtures with regards to criteria such as strength and durability. Empa researcher Frank Winnefeld explains that they have already found out that “alternative types of cement can be used to produce concrete with a comparable or even better durability.” However, appropriate industrial processes “must still be optimized as in many cases they are still too expensive.”
Image credit: LEEROY via Pixabay