Fraunhofer Institute for Building Physics IBP
Fraunhofer Institute for Building Physics IBP

ReAsCon - Innovative Processing Solutions for Legacy Contamination

View of the elevated highway in Ludwigshafen
© Mathias Weil – stock.adobe.com
View of the elevated highway in Ludwigshafen, where approximately 310,000 tons of concrete will arise during demolition.

The construction industry is facing a major challenge: each year, around 90 percent of all domestic mineral raw materials used in Germany are consumed by construction projects. At the same time, many valuable construction wastes - particularly from older buildings - are landfilled or insufficiently recycled. Structures built between the 1960s and 1980s are especially affected, as they often contain fibrous silicate minerals. These legacy contaminations frequently result in otherwise recyclable concrete having to be disposed of as hazardous waste. The ReAsCon project therefore pursues an innovative approach for processing and recovering such unwanted legacy materials in the construction sector.

Project goals

The primary objective of the ReAsCon project is to develop innovative solutions for the selective separation and processing of contaminated demolition materials. Using the elevated highway in Ludwigshafen as a case study, where approximately 310,000 tons of concrete will be generated during dismantling, the Fraunhofer Institute for Building Physics IBP is working closely with its project partners.

The chemical and mineralogical characterization of the demolition materials is carried out using state-of-the-art analytical methods, including X-ray diffraction and X-ray fluorescence analysis. A particular focus is on the investigation of fine fractions below two millimeters, as critical fibrous materials may accumulate in these size ranges. The overall process aims to separate the contaminated components while recovering high-quality construction materials such as autoclaved aerated concrete, recycled concrete, or cement substitute raw materials.

Project status

Within the collaborative ReAsCon project, Fraunhofer IBP contributes its long-standing expertise in the analysis and processing of mineral material streams. Together with Fraunhofer IOSB, a novel detection method is being developed that enables rapid and effective on-site identification of mineral fibers. This camera-based system utilizes the pleochroism effect and does not require complex sample preparation. Following the successful separation of contaminated fractions, appropriate recycling pathways for the cleaned material fractions are being developed. The institute’s own saturated steam autoclave enables the production of demonstrators at pre-industrial scale. In addition, Fraunhofer IBP supports the installation and validation of the detection system at the industrial partner’s site and provides scientific support for the large-scale trials. Through this comprehensive approach, Fraunhofer IBP makes a significant contribution toward returning valuable secondary raw materials to the circular economy, conserving landfill capacity, and sustainably improving the carbon footprint of the construction sector.

Project Partners

  • Technical University of Darmstadt – Institute for Solid Structures (project coordinator)
  • Scherer & Kohl GmbH
  • Construction Project Company Ludwigshafen GmbH
  • Fraunhofer Institute for Building Physics IBP
  • Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB
  • Construction Industry Association Baden-Württemberg e.V.
  • Metropolregion Rhein-Neckar GmbH
  • Industrial Ecology, Birkenfeld Environmental Campus (UCB) at Trier University of Applied Sciences
  • City Administration of Ludwigshafen