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In Germany the use of recycled aggregates is possible within certain limits since the introduction of the DAfStb guideline in 1998. Due to increasing demands of concretes fulfilling requirements regarding sustainability, conservation of resources and avoidance of waste the topic of recycled aggregates has again become the focus of public, economic, and political interest in recent years. Although the results of the BMBF research project "R‐Beton" have led to positive changes with respect to the regulation gap in environmentally relevant characteristics several certain barriers still prevent the broad use of recycled aggregates in the German concrete market. In the forthcoming DIN 1045, regulations will be created which, particularly in concrete class BK‐N in the application range of up to 25 % volume fraction, will permit simple and thus practical use of recycled aggregates. In addition, fine recycled aggregates of type 1 may be used, which was previously not permitted. Here, changes in the regulatory framework of DIN 1045 will be discussed in the sense of a broader use of recycled aggregates in Germany as well as the context of other national regulations. An outlook regarding further need of research is also given. [ABSTRACT FROM AUTHOR]

There are major challenges which the cement industry in Germany and the entire cement and concrete value chain are facing in their quest for climate neutrality and preservation of natural resources. The studies on decarbonisation and resource conservation recently published by VDZ underline the claim of German cement manufacturers to actively promote decarbonisation and to further significantly reduce the use of primary raw materials in the value chain of cement and concrete. Within the context of a 2050 scenario, various potentials for decarbonisation and resource conservation are being identified and quantified. In addition, the necessary prerequisites and action strategies for implementing the savings potential are explained. [ABSTRACT FROM AUTHOR]

Deep‐ploughing far beyond the common depth of 30 cm was used more than 50 years ago in Northern Germany with the aim to break root‐restricting layers and thereby improve access to subsoil water and nutrient resources. We hypothesized that effects of this earlier intervention on soil properties and yields prevailed after 50 years. Hence, we sampled two sandy soils and one silty soil (Cambisols and a Luvisol) of which half of the field had been deep‐ploughed 50 years ago (soils then re‐classified as Treposols). The adjacent other half was not deep‐ploughed and thus served as the control. At all the three sites, both deep‐ploughed and control parts were then conventionally managed over the last 50 years. We assessed yields during the dry year 2019 and additionally in 2020, and rooting intensity at the year of sampling (2019), as well as changes in soil structure, carbon and nutrient stocks in that year. We found that deep‐ploughing improved yields in the dry spell of 2019 at the sandy sites, which was supported by a more general pattern of higher NDVI indices in deep‐ploughed parts for the period from 2016 to 2021 across varying weather conditions. Subsoil stocks of soil organic carbon and total plant‐available phosphorus were enhanced by 21%–199% in the different sites. Root biomass in the subsoil was reduced due to deep‐ploughing at the silty site and was increased or unaffected at the sandy sites. Overall, the effects of deep‐ploughing were site‐specific, with reduced bulk density in the buried topsoil stripes in the subsoil of the sandy sites, but with elevated subsoil density in the silty site. Hence, even 50 years after deep‐ploughing, changes in soil properties are still detectable, although effect size differed among sites. [ABSTRACT FROM AUTHOR]