In the BnB project, prefabricated building elements will be developed with a high content of recycled construction and demolition waste (> 30%). The intention is to use advanced breaking and sorting technology (microwaves) to produce pure raw materials that can be reused as binders, fillers or aggregates for prefabricated building elements. Scaling-up, the developed building material will be used to produce prefab concrete resistant to aggressive environments. This project aims to contribute to achieving the EU recycling target for construction and demolition waste of 70%. This project specifically looks at the recycling of concrete and the potential of microwaves for the pre-treatment of residual mineral flows.