Field Application of a Thermal-Sprayed Titanium Anode for Cathodic Protection of211 Reinforcing Steel in Concrete

摘要

This study provided the first field trial of a catalyzed, thermal-sprayed211u001etitanium anode for cathodic protection of steel reinforced concrete structures. 211u001eCatalyzed titanium as an anode material offers the advantage of long life due to 211u001ethe inherent non-corrosive nature of the metal in atmospheric exposure. To 211u001econtinue to serve as an anode, the titanium will require a periodic and easily 211u001eaccomplished re-application of the catalyst rather than re-application of the 211u001emetal. The purpose of this study was to evaluate the installation and operation 211u001eof the catalyzed titanium anode and to evlauate the economics of the titanium 211u001eanode system compared to thermal-sprayed zinc. The initial phase of the study 211u001eincluded modification of the spray equipment for spraying titanium wire and 211u001edetermination of the optimal spray parameters for applying the titanium anode to 211u001ethe bridge. Coating resistivity was found to be the best measure for evaluating 211u001ethe effectiveness of the coating. Decreasing spray distance, increasing current, 211u001eand using nitrogen as the atomizing gas (propellant) all decrease coating 211u001eresistivity. A multiple regression equation developed from the collected data 211u001eshowed that, for the data collected in this study, spray gun travel speed 211u001eatomizing gas pressure have an insignificant effect on coating resisivity.