Germany's central location in Europe has led to steadily increasing traffic volumes for many years. In the future, the stress on the entire road structures will increase considerably. For this reason, it is more important than ever to build stable and low-deformation roads that can absorb the ever-increasing loads without damage in terms of their long-term behavior.An important type of high-quality base course, especially for roads subject to higher loads, is the hydraulically bound base course (HGT). These layers consist of well-graded gravel-sand or crushed stone-chip-sand mixtures, usually bound with cement or cementitious base course binders. Both types of binder are based on burnt cement clinker, the production of which is associated with high energy consumption and high emissions of, for example, around 1 kg of CO2 per kg of cement clinker.The reason for and background to this research project is thus the endeavor to develop new and resource-saving binders for hydraulically bound base courses in line with the sustainability strategy of the German government. At the same time, this can open up a new, economically very interesting field of application for industrial by-products such as granulated blast furnace slag, hard coal fly ash or even for the lime-rich lignite fly ash, which has been practically unusable up to now. This opens up possibilities for the high-quality use of industrial by-products with the well-known economic advantages: Conservation of landfill space and raw material resources, reduction of CO2 emissions through alternative binders and transport distances, possibilities of cost reduction etc.