Accounting for Temperature Effects on an Evolving Galvanic Anode Cathodic Protection System for Steel in Concrete

Temperature changes affect current delivery and electrochemical assessment of galvanic anode–steel in concrete systems. Interfacial corrosion processes are thermally activated and, hence, temperature dependent. In addition, concrete resistivity varies with temperature, with consequent change in any resistive polarization component that may be present. This work presents advances in the approach to temperature correction procedures. Galvanic current, electrode potentials, and resistivity measurements were determined as a function of concrete temperature in outdoor reinforced concrete slabs where sacrificial point anodes were connected to the steel. Measured values were successfully standardized to an equivalent resistivity/current at a predefined reference temperature, through the application of a master temperature correction equation based on a differential formulation that derived correction parameters from short-term fluctuations and filtered long-term aging trends. A refined steel cathodic polarization characterization was introduced and demonstrated by accounting for the effect of electrode potential, as an added term to the nominal activation energy of the cathodic reaction.