Fraport Tests Sustainable Asphalt Based on Cashew Nuts  

Test stretch in the south of Frankfurt Airport – Biogenic raw materials contributing to climate protection – The world’s first use at an airport

Fraport AG is exploring new, innovative approaches for the use of construction materials. Together with the startup “B2Square – Bitumen Beyond Oil,” the airport operator is using sustainable asphalt concrete to build and test a 200-meter-long section of road located on the airport apron. This is the first time that organic cashew-based bitumen has been used at an airport anywhere in the world.

Sustainable low-temperature asphalt concrete

Bitumen is indispensable for road construction. It is normally obtained as a byproduct when distilling crude oil and then mixed with mineral aggregate to make asphalt concrete (also known as blacktop) for building roads. In this case, however, B2Square is blending naturally occurring hydrocarbon resin with an organic extract obtained by pressing cashew shells. The resulting material is then mixed with aggregate to make sustainable asphalt.

Reduced carbon footprint

This biogenic raw material is much more durable and climate-friendly than conventional asphalt concrete. Like all plants, cashew trees extract carbon dioxide from the atmosphere. The CO₂ stored in cashew shells is neutralized in a special process and then permanently bound in road pavement. The low-temperature method used to lay it additionally improves the climate balance by consuming less energy.

“We regard this innovative bioasphalt based on organic bitumen as a fascinating possibility for reducing Frankfurt Airport’s carbon footprint,” says Andreas Eibensteiner of Fraport AG’s Environmental Management Department. “For decarbonizing the Fraport Group, we’re mainly focusing on avoiding CO₂ emissions in the areas that we directly impact. Greater attention is also being paid to scope 3 emissions, including those caused by construction activities. It’s important to look for innovative ways to reduce the climate footprint of our supply chains,” he explains. “If it’s confirmed that this novel pavement meets our strict quality requirements, the airport’s apron areas have huge potential for continuing to roll out this process. To effectively combat climate change, you have to think out of the box and try out ingenious approaches like this one.”

By using bioasphalt, Fraport is also already complying now with new laws that will limit exposure to steam and aerosols at workplaces starting in 2025.

Test stretch on the apron

At the Kelsterbach asphalt plant not far from the airport, the material is mixed with crushed rock and loaded onto trucks that take it to construction sites. The test stretch is located in the southern part of the airport’s apron. Fraport AG is paving one side of it with sustainable bioasphalt and the other with conventional asphalt. Vehicles will drive to the end on one side, then turn around and drive back on the other side. This balanced use is an important prerequisite for obtaining useful results.

Trial monitored by regular checks

The independent laboratory HNL Ingenieur- und Prüfgesellschaft mbH in Aschaffenburg is monitoring the project. “Over the next two years, we hope to gain valuable insights on the durability of this sustainable asphalt,” explained Axel Konrad, a project manager in Fraport AG’s Central Infrastructure Management department. “Checks are being carried out every six months. The extent of compaction and the void content of the asphalt material are crucial parameters. Whether or not we continue using the bioasphalt will depend on the results.”

Fraport AG’s climate protection goals

By 2045 at the latest, Frankfurt Airport and all of Fraport’s other fully consolidated facilities will operate with zero carbon dioxide emissions. And in 2030, the airport operator will have already reduced them at its homebase to 50,000 tonnes annually. The activities to support climate protection are based on a decarbonization plan for the entire corporate group that was adopted in 2023.

More information on Fraport’s climate protection activities is contained in the climate protection press kit. Our biobitumen press folder contains more information (in German) on the described sustainable construction site.

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