An original concept is presented for the rehabilitation of concrete structures. The main idea is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) to “harden” those zones where the structure is exposed to severe environmental and high mechanical loading. All other parts of the structure remain in conventional structural concrete as these parts are subjected to relatively moderate exposure. This conceptual idea combines efficiently protection and resis-tance properties of UHPFRC and significantly improves the structural performance in terms of durability and life-cycle costs of the rehabilitated concrete structure. The concept is validated by means of four applications demonstrating that the technology of UHPFRC is mature for cast in-situ and prefabrication using standard equipment for concrete manufacturing.