Paving the Way for More Asphalt Recycling in Switzerland
Recent tests on Swiss roads have shown promising results for recycled asphalt. Researchers reported that in Uster, Canton Zurich, and on the Lukmanier Pass in Canton Graubünden, they were able to increase the use of recycled asphalt without sacrificing performance.
A collaborative effort involving the Swiss Federal Laboratories for Materials Science and Technology (EMPA), the Federal Roads Office (ASTRA), the Federal Office for the Environment (BAFU), the cantons of Zurich and Graubünden, and industry partners aimed to boost the use of recycled asphalt in road construction. Switzerland has been generating more asphalt waste than it can reuse, with around 750,000 tonnes ending up in landfills annually.
One major challenge to asphalt recycling has been the ageing and stiffening of the asphalt binder over time, leading to cracking. EMPA researchers have developed calculation models to address this issue, allowing for the calculation of the right mixture for specific applications and the correct dosage of rejuvenating agents to soften the old binder in recycled asphalt.
In one test on Aathalstrasse in Uster, 30% recycled asphalt was added to the surface course, even though it’s not typically used in heavily trafficked roads. Surprisingly, there were no cracks observed. Similarly, on the Lukmanier Pass, which experiences challenging climate conditions, recycled asphalt performed well despite temperature fluctuations.
EMPA will continue monitoring these test stretches over the next two years to assess their long-term performance.
