An original concept is presented for the durable rehabilitation and strengthening of concrete structures. The main idea is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) complemented with steel reinforcing bars to “harden” and strengthen those zones of the structure that are exposed to severe environmental influences and high mechanical loading. This concept combines efficiently protection and resistance properties of UHPFRC and significantly improves the structural performance of the rehabilitated concrete structure in terms of durability. The concept has been validated by means of field applications demonstrating that the technology of UHPFRC is mature for cast in-situ and prefabrication using standard equipment for concrete manufacturing. This novel technology is a step forward towards more sustainable structures.