Overview of application areas
The following table shows the areas of application of recycled aggregates taking into account environmental regulations (LAGA Notice M20 or North Rhine-Westfalia decrees for recycled aggregates) and technical specifications of the German Road and Transportation Research Association. From an environmental point of view, a distinction is made between different material qualities, which impacts the recycling possibilities. LAGA M20 defines materials with the assignment values Z1.1, Z1.2 and Z2 and the regulation in North-Rhine Westfalia distinguishes between the material classes RCL I and RCL II. Z 1 and RCL I respectively are the best qualities.
The following requirements must be met for the scope of the table shown:
- Construction measures outside water protection areas, flood areas and outside of hydrogeologically sensitive areas
- Minimum distance between formation and highest expected groundwater level: 1 m
- Increased minimum distance between formation and highest expected groundwater level for material class Z1.2: 2 m
- A permit under water law must is required for private building projects
Although it is generally possible to reuse recycled aggregates within the protection zones WSG IIIA/HSG III and WSG IIIB/HSG IV, this is not shown here, as the possibilities are limited in this case. If the construction project is located in this type of water conservation area, we recommend a case-by-case assessment.

Resulting areas of application of recycled aggregates depending on the material class after comparison of ecological and technical specifications: Data for federal states with validity of LAGA M20 and for North Rhine-Westphalia