This International Standard specifies performance requirements for cathodic protection of steel in cement-based concrete, in both new and existing structures. It covers building and civil engineering structures, including normal reinforcement and prestressed reinforcement embedded in the concrete. It is applicable to uncoated steel reinforcement and to organic-coated steel reinforcement. This International Standard applies to steel embedded in atmospherically exposed, buried, immersed and tidal elements of buildings or structures. NOTE 1 Annex A gives guidance on the principles of cathodic protection and its application to steel in concrete. NOTE 2 This International Standard, whilst not specifically intended to address cathodic protection of steel in any electrolyte except concrete, may be applied to cathodic protection of steel in other cementitious materials such as are found, for example, in early 20th century steel-framed masonry, brick and terracotta clad buildings. In such applications, additional considerations specific to these structures are required in respect of design, materials and installation of cathodic protection; however, the requirements of this International Standard may be applied to these systems.