Spoiler alert: We’re doing that already! Because sometimes the pavement has deteriorated to such an extent that it is no longer enough to simply fill in the potholes – the entire asphalt has to be removed and replaced. When the old, removed asphalt is reprocessed for reuse, we speak of asphalt recycling. What few people know is that asphalt recycling has been common practice for years.
How does asphalt recycling work?
The recycling process of asphalt can be compared to the recycling of plastic bottles or used glass.
Asphalt recycling involves the removal of brittle or cracked asphalt by breaking away entire slabs or milling it off in layers using an asphalt milling machine. The stripped material is then taken to an official asphalt collection point, i.e. a landfill for used asphalt. There, the material is processed for reuse. First, the asphalt is broken down even more and sieved. A certain amount of this asphalt can be added to new material at the asphalt mixing plant to produce new asphalt.
A wonderful side effect:
Asphalt production uses bitumen as a binder to glue together the asphalt aggregates. Bitumen is a petroleum product obtained from the distillation of crude oil, a raw material whose use, for environmental reasons, should be avoided. Recycled asphalt already contains bitumen, so recycling asphalt not only cuts down on the need for new asphalt material, it also reduces the dependency on fossil petroleum. So recycling asphalt has a twofold benefit, saving both resources and the environment.
How much recycled asphalt does STRABAG use in its road construction projects?
STRABAG currently uses 385,000 tonnes of recycled asphalt a year in Austria alone. We are convinced, however, that we can do even better!
STRABAG is constantly pushing the limits of what is technically possible in asphalt recycling, for example by conducting research into how to best achieve high recycling rates while maintaining high standards of product quality. Based on our findings over the past few years, we are certain that recycling rates can be significantly improved. To put research into practice, we are in talks with our clients to convince them to use more recycled asphalt than previously stipulated in project tenders. Because asphalt recycling makes an important contribution to resource conservation.
Austria's most modern asphalt mixing plant
We are particularly proud of our asphalt mixing plant in Hausleiten, the most modern plant of its kind in Austria. The plant uses a modern technology known as hot recycling of asphalt paving mixtures, which theoretically allows us to produce asphalt with a recycled content of up to 100 %. In practice, most of the mixtures we produce currently have 50 % recycled asphalt, though we are also testing a recycled content of up to 70 % for some types of asphalt.
Division manager Reinhard Kerschner repaved his driveway with 70 % recycled content
We believe in the technology of asphalt recycling. As a demonstration, Reinhard Kerschner paved his private driveway using a maximum recycled content. In our interview, the Austrian division lead explains how it was done.
We will invest even more in the infrastructure of our production facilities. For me, asphalt recycling is a technology that we can not only use very effectively already, but that also offers a lot of room for improvement.