The University of Liège owns an impressive tool to study collision dynamics: a 15m tall impact ramp dominates the Mechanics of Materials and Structures Laboratory. Already used to test shock absorbers constructed from recycled metal materials, this ramp could be used to study other fields of application.

The impact ramp was produced within the framework of a combined research action project (ARC) subsidized by the French speaking community. The project, named ‘macro cell metal foams: a new material for road safety and robustness in civil engineering,’ aimed at studying and characterizing a new type of material, metal macro foams. A foam is essentially made up of air and relatively little matter. It is named a macro-foam when the voids which make it up are of a size in the order of a centimetre, and are called a micro-foam when they are significantly smaller. If micro-foams are light structures which are already highly valued in the very specialised domains of aeronautics and aerospace, they are unaffordable for road safety and civil engineering due to the high costs of their manufacturing processes.

On the other hand, metal macro foams could soon become shock absorbers in addition to the tyre walls, concrete barriers and metal guard rails on our roads. Even if at the outset they did not especially meet the demands of road safety, these macro-foams have an undeniable ecological asset as they give a second life, before they are melted down, to metal cans and other waste products which have their origins from the selective sorting of refuse sacks, whilst at the same time placing on the market a new product arising from Walloon know-how.