Asphalt is, in many ways, a black product. But a new experiment featuring an unusual ingredient might pave the way toward greener roads. On a parking lot near the Fehmarn project in Rødbyhavn, Lolland, groundbreaking technology is being tested in real-world conditions.
Kilometer-long fungal root systems, known as mycelium, weave around the small stones that make up the bulk of the asphalt mixture.
Fossil-free binder
The mushroom-based asphalt is the brainchild of Visibuilt, a company that has developed an alternative to the carbon-heavy bitumen—a vital component in traditional asphalt production derived from oil. Instead of using bitumen, the company has created a fossil-free binder made from mushrooms.
This experiment is a collaboration between Visibuilt, Sund & Bælt, Fehmarn Link Contractors (FLC), NCC, and several research and educational institutions. Sund & Bælt, the client for Denmark’s largest infrastructure projects, sees great potential in the trial.
– As the client for some of Denmark’s largest infrastructure projects, we aim to promote solutions that can make the industry greener. We are delighted to contribute to this development in collaboration with our contractors and ambitious companies, says Christian Henriksen, Environmental and Regulatory Affairs Manager at Sund & Bælt, in a press release.
No heating required
The binding agent, called visiBIT, uses mycelium—the root-like underground network of fungi—to hold the stones in the asphalt together. Beyond being a natural, bio-based binder, visiBIT also eliminates the need for energy-intensive heating during production. This is a crucial step in reducing the material’s carbon footprint.
Traditional bitumen requires heating to temperatures of up to 200 degrees Celsius during asphalt production, significantly increasing CO2 emissions.
Although this new type of asphalt is still in its early development stages, Visibuilt views the Fehmarn project trial as a success.
– Our solution is the world’s first fermented binder for the asphalt industry, and it’s entirely unique. By eliminating the need for heating, we drastically reduce energy consumption during production. The trial has exceeded expectations, and we’ve demonstrated that we can construct an asphalt surface using visiBIT with standard industry equipment, says Line Kloster Pedersen, CEO of Visibuilt.
The trials at the Fehmarn construction site are among the first of many planned experiments to test the durability of this new type of asphalt. Durability is key to reducing the carbon footprint of roads. The company expects to use visiBIT for bike paths by 2026.
Facts about the asphalt experiment
- Visibuilt was founded in early 2023 by CEO Line Kloster Pedersen, who has a background in biotechnology.
- The experiment is a collaboration between Sund & Bælt, Visibuilt, Fehmarn Link Contractors (FLC), NCC, DTU, the University of Copenhagen, the National Research Centre for the Working Environment (NFA), We Build Denmark, and Erhvervshus Sjælland.
- The Technical University of Denmark (DTU) is monitoring the asphalt’s development over time and conducting field measurements, including temperature, humidity, and traffic loads.
- The University of Copenhagen and NFA have examined worker exposure during the trial and will compare air quality when laying visiBIT asphalt with traditional bitumen-based asphalt.
Kilde: Sund & Bælt
