Canton Basel-Stadt to use CO2-negative asphalt in future


Basel – The canton of Basel-Stadt wants to use green asphalt for road works in the future. The new mix tested and found to be good contains 50 percent recycled asphalt and 2 percent vegetable carbon produced by Industrielle Werke Basel (IWB). It binds more CO2 than traditional asphalt causes.

The Department of Construction and Transport of the Canton of Basel-Stadt, together with ViaTec Basel AG, Institute for Construction Materials Technology, has developed a CO2-negative asphalt as part of a research project. It should significantly reduce the CO2 footprint of Basel’s road construction.

According to a media release, various asphalt mixtures with different proportions of vegetable carbon were tested. Certified vegetable carbon is produced by IWB in its own plant from green waste. It consists of the carbon portion of the CO2 that the plant has extracted from the environment during its growth. Their further use in asphalt permanently removes CO2 from the atmosphere.

Finally, the Basel-Stadt Civil Engineering Office has been testing a load-bearing asphalt layer made of 50 percent recycled asphalt and 2 percent vegetable carbon on a transfer station for recycled building materials since 2022. The results are reportedly “extremely positive”: one ton of the new asphalt mixture permanently binds the equivalent of 50 kilograms of CO2. Now it will also be possible to use the technology on a large scale in Basel.

Now, the Basel-Stadt Civil Engineering Office, together with the regional pavement mixing plants, wants to simplify the production process and use the vegetable carbon asphalt as comprehensively as possible for necessary road rehabilitations. The city expects to be able to permanently store around 1250 tons of CO2 equivalent in Basel’s streets each year in this way. This is about 450 tons more than asphalt production for road construction causes. ce/mm