Large floors of industrial enterprises, warehouses, stores, and shopping centres are quite heavily loaded with production technologies, transport mechanisms, stored material or shelf stackers. Regarding simple reinforcement and construction, industrial floors have been used in recent decades mainly reinforced with fibres from so-called fibre-reinforced concrete. Most slab failures are caused by extreme loads on the unbearable subsoil, a small amount of fibres, or by the shrinkage of concrete due to insufficient structural design of sliding, shrinking and expansion joints. Recently, however, in several constructions, structural failures have occurred caused by a volume-unstable subsoil in the form of a mixture of slag or metallurgical debris...