Swiss researchers are developing a way to stop potholes forming by injecting asphalt with iron-oxide nanoparticles that helps prevent cracks, as Matthew Stock reports.
Potholes are a common sight on many roads and the bane of motorists' lives. But 'self-healing' roads, impervious to cracks and potholes, could be around the corner. This is bitumen - the sticky, viscous, black binder used in road construction. ETH Zurich scientists have added magnetic nano-particles to the mixture. SOUNDBITE (English) ETIENNE JEOFFROY (PRON. JOFF-WAH), PHD STUDENT AT ETH ZURICH COMPLEX MATERIALS LAB, SAYING: "The binder that comes from the crude oil distillation and we, in fact, mix in all these stones that give the structure if the road...So the idea is that we have nano-particles that are fused with this binder." Slightly heating roads made with this binder melts it just enough to seep into surrounding cracks. SOUNDBITE (English) ETIENNE JEOFFROY (PRON. JOFF-WAH), PHD STUDENT AT ETH ZURICH COMPLEX MATERIALS LAB, SAYING: "You will come with the magnetic field to heat up this road through these nano-particles, and then this black binder will be able to flow in to close the micro cracks." To be completely self-healing, roads must be constructed entirely using their nano-particle mixture. Constant road stress means a once-yearly treatment would be needed. For this the team envisions maintenance vehicles equipped with giant magnetic coils to quickly kick-start the healing process. As for the dreaded pothole; the mixture could be used on existing roads; acting like a skin graft to form a new layer. SOUNDBITE (English) ETIENNE JEOFFROY (PRON. JOFF-WAH), PHD STUDENT AT ETH ZURICH COMPLEX MATERIALS LAB, SAYING: "You can have a little bit of nano particles inside the mixture, and apply a magnetic field locally to give enough temperature to make the joint between the new material and the old road." The team has patented their nano-particle solution. They're looking for commercial partners to help scale-up the system... hopefully giving them a smooth path to market.