To protect natural resources, circular economy in the construction industry has to be further established. In many cases today, demolition material from concrete structures is recycled in a very low value or landfilled. In urban areas, where the temporary construction pit system is used during the construction phase, large volumes of demolition concrete are produced at the end of the construction period. This concrete waste should be recycled to high quality recycled concrete aggregates (RCA) in the sense of urban mining. In this research project, the material from a demolished diaphragm wall is investigated for its recyclability and further production of watertight structural walls in the infrastructure sector. In particular, the workability of the material in concrete production as well as the hardened concrete properties such as watertightness and permeability are parameters that are investigated during the research. The tests will be carried out on test specimens as well as on test walls. By establishing the recycling process, the material could be processed and reused on the construction site. This helps to reduce the use of natural resources and conserve areas that would otherwise be used for landfilling.