ABSTRACT
In terms of cathodic protection (CP)of reinforced and prestressed concrete structures and buildings, it is accepted that a properly designed, installed, operated and maintained impressed current system will halt reinforcement and prestressing steel corrosion in concrete regardless of the chloride content or extent of carbonation of the concrete as well as the extent and rate of reinforcement or prestressing steel corrosion. Various impressed current anodes are available including: soil/water anodes; mesh anodes; ribbon/grid anodes; discrete anodes; arc sprayed zinc; and conductive organic coatings. Galvanic CP utilising soil/water anodes, thermally sprayed metals (zinc and aluminium-zinc), zinc mesh with fibreglass jacket and zinc sheet anodes is also possible. The actions of CP (thermodynamic and kinetic), criteria for CP, key selection, and design issues, stray current corrosion, and interference, commissioning, system documentation, and operational matters are all discussed. Cathodic prevention, CP to new structures, is outlined.
