Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB 
Short description of the project
Sustainable construction is assuming an increasingly important position in the construction sector. For this reason, a research consortium of four Fraunhofer Institutes has joined forces to address the challenge of resource conservation, reuse of building materials and high-quality recycling of building materials. In the process, the BauCycle project was launched and has been funded since the beginning of 2016 until the end of the project in 2019 as part of the Fraunhofer Gesellschaft's internal programs.
Project goals
The aim BauCycle is to sort and process demolition materials into recycled building materials that can then be returned to the original construction cycle. This is intended to reduce the use of primary raw materials, enable more sustainable construction and counteract the shortage of landfill space.
Project results
The main focus of the Fraunhofer IOSB project was the development of a process for the optical sorting of crushed construction waste in order to selectively separate its main components concrete, brick, sand-lime brick and gypsum. Based on hyperspectral sensor technology and the widely tested IOSB sorting technology, a purity of approximately 99.5 percent was achieved.
In parallel, the project worked on building product samples and formulations. For example, autoclaved aerated concrete blocks were produced in which 30 percent by mass of the primary raw material sand could be replaced by the obtained fine-grained construction waste material, as were cement-free construction materials based on construction waste.
