BAUSEP

BAUSEP - Development of resource-efficient construction products from ash and slag

Resource-efficient circular economy - construction and mineral material cycles (ReMin)

The demand for construction products continues unabated. However, raw materials such as sand, gravel and crushed natural stone are becoming increasingly scarce. This is where the BAUSEP project comes in by making mineral secondary raw materials from ash and slag available for the development of resource-efficient construction products.

The project is being funded as part of the "Resource-efficient circular economy - construction and mineral material cycles (ReMin)" funding measure. "ReMin" is part of the BMBF research concept "Resource-efficient circular economy" and aims at resource-efficient construction and the extended use of mineral secondary raw materials from construction waste, slag, ash and mining residues.

Development, evaluation and production of resource-efficient construction products

Every person in Germany uses over 450 tons of sand, gravel and crushed natural stone in their lifetime. However, these raw materials are becoming increasingly scarce. Ideally, as part of a resource-efficient circular economy, waste materials are turned back into raw materials of equal or greater value. The construction industry still has great development potential in this respect, which the BAUSEP project aims to tap into.

The overarching goal of BAUSEP is the development, evaluation and production of resource-efficient construction products through the use of processed ash and slag. Specifically, waste incineration ash and slag from steel production are to be provided as a substitute for primary aggregates, thereby sustainably reducing the extraction of natural rock deposits and the associated landscape consumption. Resource-efficient concrete components, such as paving stones and channel segments, are then to be developed from the substitutes and their sustainability demonstrated through an accompanying life cycle assessment and techno-economic analysis. Supplementary studies on technical and legal aspects will also shed light on the future use of processed incinerator bottom ash and slag in marketable and marketable construction products.

Pooling relevant players along the use chain

To this end, BAUSEP is pooling the expertise of relevant players along the usage chain throughout Germany. At the start of the project, Stadtreinigung Hamburg and thyssenkrupp MillServices & Systems are providing suitable waste incineration ash and slag. These are comprehensively characterized at the Department of Geosciences and Environmental Sciences at LMU Munich and freed of any valuable and foreign substances at the CUTEC Clausthal Environmental Technology Research Center at Clausthal University of Technology. Based on the materials provided, the Fraunhofer Institute for Building Physics IBP is developing building products on a laboratory scale. The company bvw Steinwerk Hamminkeln will be closely involved as a future producer.

This will simplify the transfer to industrial scale and the production of paving stones and channel segments. In the interests of a resource-efficient circular economy, the recyclability of the newly developed construction products will be tested in addition to their durability. Fraunhofer IBP will continuously incorporate all the findings into a life cycle assessment and techno-economic analysis. In order to enable the project results to be used in the construction industry from 2024, KM GmbH für Straßenbau- und Umwelttechnik is examining the legal framework and advising the project partners on an ongoing basis on the use of ash and slag in construction products.

Industrial residues for use in construction materials

BAUSEP will identify specific ways in which industrial residues can be used in construction materials, thus saving primary raw materials. By involving relevant players along the value chain, recommendations for action can be derived to what extent the realization of a sustainable circular economy for secondary raw materials in building product manufacturing is expedient. The expertise gained will be made available to construction product manufacturers, construction companies, planning offices, universities and other users. In this way, the use of secondary raw materials while at the same time conserving natural resources should find its way into everyday life in the construction industry.