What you see in a close-up image during the trial on the test-track with the induction machine is that the asphalt is heated. But especially the bitumen heats up and the aggregates do not. This is perfect and it works as we intended it to be. Only the bitumen is heated by the 'hot' fibres. The aggregates should stay cold in order cool the material down again. In that way the cars can use the road shortly after the treatment.
Self Healing Aspalt on the A58
On this Blog we will give info on the test track with Self Healing Asphalt that is built on the A58 near Vlissingen in The Netherlands. The Asphalt is a special type of ZOAB (very porous aphalt concrete) containing small steelwool fibres. A known but serious problem with ZOAB is ravelling: stones at the surface coming off in time due to microcracking in the binder. The special ZOAB that is developed at Delft University (sponsored by AgentschapNL) can be heated with induction energy due to the fibres that are present which closes the microcracks and with that extends the service life of the road.