Application of binders with lower carbon footprint in the AAC production

Autoclaved aerated concrete (AAC) is a building material that mainly contains calcium silicate hydrate phases, especially 11 Å tobermorite. For forming these mineral phases, calcium ions from the binders and silicon ions from the milled sand are necessary. Currently, hard‐burnt lime and Portland cement are used as binders for AAC production. Both raw materials contribute significantly to the carbon footprint of AAC products. On the way to climate neutrality of AAC production, it is thus necessary to replace hard‐burnt lime and Portland cement with binders with a lower CO₂ impact. Therefore, tests with middle‐burnt lime in combination with different Portland limestone cement were carried out to investigate their influence on processing, material properties, and the mineral phase composition. It can be concluded that both these lower CO₂ impact raw materials can be used for AAC production, as there are no changes in material properties and mineral phase composition.