Electric vehicles, hydrogen buses, bicycles… Transport modes and habits are changing to adapt to the challenges of the environmental and climate crisis. But what about the roads we travel on? While France has over a million kilometers of roads, they are mostly made of bitumen. This material comes from the distillation of petroleum and is therefore not ecological or sustainable. The Eiffel Laboratory is working on an alternative to make tomorrow’s roads greener: bitumen made from plant materials. Focus on an innovative and promising device.
In France, almost 3 million tons of bitumen are used annually for the construction of roads (90%) or waterproof roofs (10%). Problem: This mixture of hydrocarbons comes from the distillation of petroleum, a resource of fossil origin and non-renewable. With a view to building more sustainable roads, Eiffel’s lab has just developed a section of road made of plant material, the program reports Quiet, it’s growing! broadcast on France 5.
“This bituminous mix, which is made from aggregates and bitumen, is made from bitumen from plants, so a residue from kraft paper production”, says Emmanuel Cailleux, a researcher at the University of Gustave Eiffel. To assess the durability, the road section was put to the test by a machine called “the carousel of fatigue”, which simulates the passage of trucks on a roadway. The vegetable mix passed the test successfully, as 2 million loads passed this road without breaking. “It held up better than conventional solutions”rejoices Emmanuel Cailleux.
Greener roads that last 20 or 30 years
The research lab is currently investigating various leftovers from the food industry to find other alternatives. “Solutions will have to be local” to limit the environmental cost, says Emmanuel Cailleux. The aim of the researchers is to find biomass in large quantities, which can be easily converted and which is not used for human food: “we don’t want to put what we can eat on the road”† For now, scientists are working on pine resins that come from the forestry industry to develop plant-based bitumen.
Nearly 10% of roads in France are already made with a binder made from waste paper pulp and pine resin, according to France 5. Bitumen made from plant material called “Biophalt” has also attracted public works companies: “we are going to heat it to 140°C instead of 160°, which is interesting for us in terms of energy savings”François Olard, technical director of research and innovation at Eiffage. According to him, this innovative material “gives a road that has a fairly classic look and will last 20 or 30 years†
Watch (a report from France 5):
This encouraging innovation suggests that roads, like vehicles, could take a greener turn.