This research project is investigating the possibility of integrating recycled material containing sulphate into the production of sand-lime bricks. Sand-lime brick masonry is often processed with gypsum plaster. Due to the adhering gypsum plaster, it is technically and financially costly to recover it as recycling material during demolition. The sulphate-containing demolition material is therefore often classified as hazardous waste and cannot currently be reused. The aim is to improve the physical properties of the sand-lime bricks or reduce the amount of lime in order to reduce the_{CO2 footprint}. By adding sulphate-containing material, new phases can be formed that react with quartz powder to form strength-forming tobermorite. This can increase the strength of the sand-lime bricks produced. A lower dose of lime while maintaining the quality of the bricks could also reduce CO2 emissions. The focus is on the integration of sulphate-containing demolition material into the material cycle of sand-lime bricks. This project aims to find solutions for the reuse of this material and thus make the building materials cycle more sustainable.