SPRAYED TITANIUM COATINGS FOR THE CATHODIC PROTECTION OF REINFORCED-CONCRETE

Thermally sprayed titanium coatings were investigated in the laborator y as anodes for the cathodic protection of reinforced concrete. Three proprietary catalyst systems were used to activate the titanium anode coatings, Some experiments were conducted that applied the catalyst as a precoat on the metallizing wires; in other experiments, the catalys t solution was applied onto concrete blocks before or after are sprayi ng with titanium. The coated reinforced concrete blocks were powered a t a constant current density and in a 95% relative humidity for more t han 95 days. The driving voltages measured across the samples demonstr ated that precoating the catalyst on the titanium wires had little eff ect on the driving voltage over the recorded lifetime. In other experi ments, where the catalyst was directly applied to the surface of the r einforced concrete blocks, only the cobalt oxide catalyst significantl y reduced the driving voltage requirements, The cobalt oxide reduced t he driving voltages regardless of whether it was applied on the concre te blocks before or after are spraying with titanium.