Concrete consists of a variety of natural, fossil-based raw materials such as sand, gravel, limestone and clay. The global demand of 14 billion cubic meters of concrete per year - and rising - means that these raw materials are becoming increasingly scarce. Natural areas and their ecosystems are endangered by the increased extraction of these raw materials. Coastal and river landscapes are being dredged for sand, the second most used raw material after water. The United Nations is warning of an impending global crisis.

From 2025, 2.2 billion tons of construction waste will be generated annually from building demolition and road construction. Although the recycling rates for construction waste are high, the functional value of the concrete decreases considerably compared to the original material. The majority of the concrete rubble is crushed and used as filling material in road construction or in sand and gravel pits or as cover for landfill sites.