Microanalysis of Thermal-Sprayed Titanium Anodes for Cathodic Protection of Reinforced Concrete Bridges

Abstract

This paper addresses the microanalysis techniques used to characterize thermal sprayed Ti coatings on concrete surfaces as anodes in impressed current cathodic protection (ICCP) systems. Thermal sprayed Ti anodes on concrete were electrochemically aged in laboratory studies of anode performance and service life. A thermal sprayed catalyzed Ti anode was installed on the Depoe Bay Bridge on the Oregon Coast in a field demonstration of the ICCP system. Both air and N were used as the atomizing gases during the study. Thermal sprayed Ti coatings are typically applied in an inert atmosphere or vacuum using shrouds or chambers to prevent reactions with the atmosphere. This was not possible with a structure as large as a bridge.Microanalysis of Ti and N together is difficult and the effects of O add to the complexity of the analysis. The ternary Ti-O-N system has not be well studied.