Concrete is an indispensable building material, without which it would not be possible to construct system-relevant structures - such as infrastructure buildings - in a sustainable and durable manner. However, the production of cement as a binding agent requires large amounts of thermal and electrical energy and releases considerable amounts of carbon dioxide as a result of the process.
The approach pursued by the cement industry to date of replacing portland cement, which is largely responsible for energy requirements and CO2 emissions, with alternative latent-hydraulic or pozzolanic binders is increasingly reaching its limits.

The aim of this research project is to develop an innovative process for the production of a new type of concrete additive from recycled fine concrete rubble as a substitute for cement clinker, fly ash and granulated blast furnace slag, as well as its overall characterization over the product life cycle (development, production, properties, application and recycling options). This initially includes the analysis of regional and supra-regional material flows in order to identify possible raw material sources for thermomechanical processing. 
The Karlsruhe Institute of Technology (IIP) will carry out the analyses of the material flows and the life cycle assessment of the new material (including a comparison with conventional concrete additives and substitution effects). In addition to the volume analysis, site and capacity planning as well as logistics optimization for the collection of the secondary raw material and transport to suitable processing and production plants for the new concrete additive will also be carried out. Closely linked to this is the profitability analysis of the new value chain. 

For the first time, the project will pursue a holistic approach to evaluating the use of a new type of reactive concrete additive for concrete based on recycled concrete demolition material.

Due to the generally strong regional nature of concrete production, the focus of the research is on south-western Germany. As the basic composition of concrete - cement, water and aggregate - does not depend on local characteristics, the results can be applied throughout Germany and worldwide with little effort thanks to the cooperation of the applicant companies.