Circular economy in the construction sector

R-concrete, also known as resource-saving concrete, represents a development in the construction industry that focuses on sustainability and resource efficiency. This building material uses recycled materials and CO₂-optimized raw materials to create environmentally friendly products without compromising performance.

In our R-concrete, we leverage two key factors: the use of CO₂-reduced cements and recycled aggregates. At a time when the construction industry is increasingly seeking environmentally friendly solutions, R-concrete represents a significant step in the right direction. It symbolizes our commitment to finding innovative ways to meet current demands without jeopardizing the resources of future generations.

The binding agent in concrete, i.e. the cement, is the main factor in the material’s high carbon footprint. That’s due, on the one hand, to the very high temperatures that are needed to manufacture it and, on the other, to the CO₂ that’s released during the firing process that’s used to convert the precursors into cement. In CO₂-reduced cements, a proportion of the source material is substituted with such materials as slag sand or powdered limestone. The use of our CO₂-reduced cements then cuts CO₂ emissions by up to 30% for each cubic metre of concrete. And the R-concrete’s performance is the same as that of conventional concrete.

Urban mining has become an essential tool in the conservation of such natural resources as sand and gravel, which today generally continue to be extracted as mineral resources from the ground. The urban mining approach processes and utilises building materials that have already been used and are being dismantled as a source of raw materials for new buildings.

Crushing and processing old concrete and other mineral construction waste in small proportions transforms them into a valuable and certified construction material that can be used in new concrete formulations. We source these recycled materials from certified recycling companies so that all the demands for high-quality aggregates are met. It’s possible to substitute between 30 to 35% of the gravel or crushed natural stone that is usually contained in concrete with recycled aggregates that can then be combined with cement to produce concrete with the required properties.

It is possible to use crushed old concrete alongside masonry and brick rubble. This creates a variety of interesting colours. The options for treating surfaces include, for example, fine washing, acidification and the sanding of surfaces. One aspect that makes the use of recycled concrete in architecture attractive is the fact that it’s possible to reflect the demolished old structure in the new build’s components. Corresponding finishing makes the sustainable use of recycled concrete in construction immediately visible; the technology helps save natural resources and actively contributes to the protection of the environment.