The original concept for the discrete anode was developed some 20 years ago. Since then many types of discrete anodes have been installed in a large number of concrete structures around the world. Some of the issues with the earlier types of discrete anodes were related to the durability of the anode wire and the long term performance of the electrolyte surrounding the anode.
Discrete anodes are not suitable for all applications, especially for thin con- crete elements or where the reinforcement is randomly spaced within a structure. The main area of application of discrete anodes would be thick reinforced concrete elements such as beams, headstocks or piles in tidal/ splash zones where the application of ribbon anodes leads to grout acidification in most cases.
Having in mind the long term durability of the cathodic protection compo- nents installed permanently in concrete and the importance of delivering a CP system with low maintenance costs, SPA has developed a state of the art discrete anode which can be supplied at different lengths (from 100mm to 800mm) and provides excellent current distribution and allows for full encapsulation of the anode mesh by the grout material. SPA’s anode, if installed in a suitably size hole in the concrete and in conjunction with suitable cathodic protection grout, will provide the optimum solution for cathodic protection installations.
SPA’s anode is constructed using grade 1 Titanium conductor rods and conductor bars, Elgard/De Nora Titanium MMO ribbon mesh and is manufactured under strict quality assurance procedures. Each discrete anode has a
unique identification number and is tested individually to ensure full compliance to the specification.
Type 1 : SPA 26
Type 2 : SPA 18
Titanium conductor bar tail / rod grade 1 Titanium in accordance to ASTM B265.
Type 1 (4 ribs/3 ribs) 2.1mA / 1.575 mA per 100mm active length.
Type 2 (4 ribs/3 ribs) 1.4mA / 1.05 mA per 100mm active length.