Fields of application of recycled aggregates

Safe and relevant application areas of recycled aggregates in German road construction are based on the detailed technical and environmental framework. Regionally, additional areas of application may be permitted due to slightly differing specifications in certain federal states. But the following requirements should be observed in general. These requirements represent a conservative approach and thus describe generally accepted application possibilities.

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.

Application opportunities of recycled aggregates in roads

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