Platinum Metals Rev., 1985, 29, (2), 80
Protecting Steel Reinforcement Embedded in Concrete
The application of platinum in cathodic protection systems designed to inhibit the corrosion of ships and marine structures is now well established. In addition platinised electrodes are used for the protection of underground structures such as storage tanks, buried pipelines and oil well casings. Similar electrodes may also find use on surface structures, such as bridges and multi-storey car parks.
A recently published invention relates to the cathodic protection of steel in concrete (Taywood Engineering Limited, British Appl. 2,140,456A). Previously, asphalt/concrete electrical ground beds could only be applied to surfaces that were, at least approximately, horizontal. Now it is claimed that an electrically conductive film, containing a suitable conducting pigment, enables a ground bed to be applied to undersurfaces or to the upright columns of a structure.
The primary anodes, which are stuck to the concrete structure and subsequently covered with the conductive paint, consist of titanium or niobium coated with platinum. These anodes are connected to the positive terminal of a DC system while the steel reinforcement is joined to the negative terminal, to constitute the cathode.