Circular economy : Mineral construction waste achieves "almost completely closed material cycles" in Germany

Since 1996, the "Kreislaufwirtschaft Bau" initiative has published biennial monitoring reports with data on the generation and fate of mineral construction waste. The current and now 12th report is based on 2018 data and also includes an overview of the development of mineral construction waste flows over the past two decades.

The 214.6 million metric tons of mineral construction waste generated in 2016 consisted of 125.2 million metric tons of soil and stone (58.3 percent), 58.5 million metric tons of construction debris (27.3 percent), 16.0 million metric tons of road demolition debris (7.4 percent), 14.3 million metric tons of construction site waste (6.7 percent), and 0.6 million metric tons of gypsum-based construction waste (0.3 percent). Thus, the amount of construction waste generated increased by 6.4 percent compared to the previous reporting period (2014: 202.0 million tons). The distribution of mass flows of the individual fractions remained roughly the same.

In the "Soil and stone" sector, with 125.2 million tons, excavated soil, dredged material and track ballast amounting to 96.4 million tons were recycled in surface mining and other measures, mainly in landfill construction. In addition, the production of recycled construction materials here amounted to 11.3 million tons. This sector thus achieved an overall recycling rate of 86.1 percent. Of the 58.5 million metric tons of construction waste, 45.5 million metric tons went into recycling, while 9.4 million metric tons were backfilled in excavations and recycled in landfills. Since only 6.2 percent of the material was disposed of in landfills, the resulting recycling rate was 93.8 percent.

Of the 16.0 million tons of road demolition material, 15.2 million tons could be recycled and 0.4 million tons used in landfill construction and in the backfilling of excavations, resulting in a recycling rate of 97.9 percent. Around a quarter of the 14.3 million metric tons of construction waste consisted of mineral components, along with metals, waste wood, glass, plastics and insulation material. Of this, 0.2 million tons were recycled and 13.9 million tons sent for other treatment, resulting in a recycling rate of 98.6 percent.

The recovery rate of 44.6 percent for gypsum-based construction waste is the result of 29,000 tons of recycled material and 257,000 tons recovered for landfill construction and mining. Thus, of the 214.6 million tons of mineral construction waste generated, 192.6 million tons were recycled all told, a rate across all fractions of 89.8 percent, a slight increase from the previous reporting period's 89.5 percent.

Taking into account recycled aggregates, which accounted for 60.7 million tons in the construction waste and road demolition fractions, 11.3 million tons in the soil and stone fraction, and 0.2 million tons in the construction site waste fraction, the amount of recycled construction materials produced in 2016 totaled 72.2 million tons. "More than twelve percent of the demand for aggregates is now covered by recycled building materials," summed up Michael Basten, chief executive of the German Federal Association of Building Materials - Stone and Earth.

In addition, the recycling rate of 95 percent for fractions excluding excavated soil shows "that the building materials cycle has been almost completely closed. And Dieter Babiel, Managing Director of the German Construction Industry Association, also speaks of recycling successes: "In road construction, the demolition material is almost completely recycled. Over 95 percent of it is recycled locally and then reused as construction material. Our companies have invested in innovative extraction and recycling technologies with great success."