Temperature Effects on a Galvanic Anode-Steel in Concrete System

摘要

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. The present work explores temperature correction procedures. Galvanic current, electrode potentials and resistivity measurements were determined as a function of concrete temperature in outdoors 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 more 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.