Empa repurposes old asphalt
Dübendorf ZH - Die Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) hat die Wiederverwertbarkeit von altem Asphalt aus Deponien im Strassenbau untersucht. Tests in Uster ZH und auf dem Lukmanierpass haben ergeben, dass das Altmaterial in unterschiedlichen Anteilen problemlos beigemischt werden kann.
In a research project, the Swiss Federal Laboratories for Materials Testing and Research has investigated the possibilities of recycling asphalt deposited on waste heaps in new construction and in the repair of road surfaces. According to a media release, researcher Martins Zaumanis’ goal was to increase the recycling content of asphalt. To this end, two test sections with recycled asphalt were set up in Uster ZH and on the Lukmanier Pass between the cantons of Graubünden and Ticino. The results are reportedly promising.
The research project is called HighRAP (Reclaimed Asphalt Pavement) and was carried out by Zaumanis together with the Federal Roads Office, the Federal Office for the Environment, the cantons of Zurich and Graubünden and several industry partners from 2019 to early 2023.
The tests showed that on the busy road near Uster, 30 per cent RAP content could easily be introduced without any loss of performance. “Typically today, for such a heavily trafficked road, RAP is completely dispensed with in the surface course,” says Zaumanis. For the underlying binder course, between 40 and 50 per cent RAP was possible.
The road section at the Lukmanier Pass is not exposed to heavy traffic, but to harsh climatic conditions. At an altitude of 1900 metres, the strong temperature fluctuations can cause cracks in the road surface. Nevertheless, RAP admixtures of 85 percent in the foundation layer and 70 percent in the base and binder layers above were possible.