Asphalt paving recycling
The limited availability of individual construction materials, the costs incurred in their extraction, treatment, but also the energy consumption and the emissions caused by their transport to the road works require a value-conserving usage of natural building materials.
These days in the sum of recycling possibilities, already over 80 percent of the asphalt removed from old roads is reused as a building material. Alongside a further increase in this recovery quota, an increase in the value added level in new asphalt concepts is also being striven for. For innovative asphalt construction methods that meet the special requirements of road construction, higher quality building materials are often used, which require, for example, impact- and polishing-resistant rock as well as particularly adhesive binding material. These valuable building materials thus have to be supplied again for equivalent recycling.
The BASt initiates and runs numerous projects to investigate the possibilities of the efficient use of used road building materials. A research project to recycle asphalt from open-pore asphalt has revealed that it is possible in the laboratory to produce high-quality asphalt bonding layers and stone mastic asphalts containing a high additional proportion of reclaimed asphalt while avoiding any adverse effects on the performance characteristics.
Together with the rock from the reclaimed asphalt, the bonding agent plays a key role for the further use as a road construction material. The regeneration of a heavily aged bonding agent in asphalt granulate with suitable substances (rejuvenators) can allow a higher value added stage when recycling asphalt.