A total of almost 200 t of mineral building and construction waste is generated every year and mostly deposited in landfills, or downcycled for use as low-quality secondary materials. This common practice sharply contrasts with the considerable raw material demands of the building and construction sector. One of the pivotal elements for the implementation of the German Resource Efficiency Programme is the identification of valuable properties of different construction waste materials and the detailed quantification of their potentials.
Separate collection and processing of construction waste for the purpose of recycling raw materials fit for use in the production of building materials is common practice for asphalt nowadays. However, many other building materials like gypsum or brick cannot be recycled at present, merely production residues can be treated for re-entry into the production process. To close loops, and particularly to exploit used materials from building construction, novel recovery strategies are required.
One example for innovative recovery is recycled concrete (R concrete) that contains aggregate from the processing of used concrete and masonry. This very promising recovery pathway was introduced in southwest Germany with ifeu help and support. However, parallel efforts should aim to reinforce existing recovery pathways. Mineral construction waste is traditionally downcycled for use in earthworks or as road construction materials. The establishment of reliable quality standards and comprehensive quality assurance are required to boost the use of recycled materials. These are key steps to promote acceptance among builders and building contractors.
A major future recycling challenge is the processing of soil and soil-like construction waste in accordance with the raw material standards and requirements of the building materials industry or other suitable outlets.