Vor dem Hintergrund der zunehmenden Ressourcenknappheit behandelt der Beitrag die Probleme bei der Verfügbarkeit von Gesteinskörnungen für die Betonherstellung. Zunächst werden aktuelle Fördermengen natürlicher Gesteinskörnungen in Deutschland vorgestellt und ein Ausblick auf die zukünftige Rohstoffversorgung gegeben. Die damit einhergehenden Lösungswege hinsichtlich der Verwendung von bisher wenig genutzten Brechsanden und Wüstensanden sowie der Einsatz von Waschschlämmen und von rezyklierten Gesteinskörnungen werden dargestellt. Hierfür werden Anwendungsgrenzen und Potenziale aufgezeigt.
Aggregates: Future raw material supply
Against the background of increasing scarcity of resources, the contribution deals with the problems of availability of aggregates for concrete production. First, current production quantities of natural aggregates in Germany are presented and an outlook on the future supply of raw materials is given. The associated solutions with regard to the use of crushed sands and desert sands, which have been little used up to now, as well as the use of washing slurries and recycled aggregates are presented. Limits of application and potentials are shown. The extraction of natural aggregates for concrete production has been at a continuously high level for several years. However, raw material bottlenecks are to be expected regionally in the coming years, as the loss of existing extraction sites will not be compensated for by sufficient new extraction. Instead, previously unused aggregates for concrete production can be suitable ways out. On the one hand, existing sand and gravel pits can be used more efficiently if wash slurries, which currently make the use of deeper-lying aggregates uneconomical as sediment layers, are extracted and further utilised. In addition, crushed sands and desert sands can also be used for concrete production if they are appropriately processed and their special properties are taken into account in mix development. In addition, the recycling of building materials offers further possibilities. The previous application limits of the corresponding German guideline can be extended with regard to existing research results and less restrictive guidelines in other European countries. However, since a large part of the construction waste produced is already used as aggregate in subordinate building components and is no longer available there if it is used more as aggregate in concrete, the potential for reducing the demand for natural aggregate is low.