EIS Monitoring of Cathodic Protection of Steel Reinforced Concrete Enhanced by Humectants

Abstract

The Galvanic Cathodic Protection system problem lies in its capacity to drive an adequate protective protection current from the galvanic anode to the embedded steel reinforcement. This study investigates the reaction mechanism, based on Electrochemical Impedance Spectroscopy (EIS), of the cathodic protection system by thermo sprayed zinc anodes to which LiBr and H2O have been added as humectants. Six reinforced slabs were tested. The specimens were placed in two different Relative Humidity cells. Electrochemical Impedance Spectroscopy and conventional electrochemical properties such as potential, galvanic current and polarization decay of the anode were routinely measured over a 150 days after the humectants addition. It was found that the LiBr notably improved the protective galvanic current; however this improvement was only temporary. Relative humidity had a greater impact than the LiBr addition on the concrete's resistivity.

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

“…Corrosion current has therefore long been considered an important research subject for corrosion researchers. A number of techniques have been developed and widely applied in various fields, including nuclear power systems [2][3][4], the petrochemical industry [5][6][7][8][9], aviation and space flight [10], and the construction of reinforced concrete structures [11][12][13][14][15]. These techniques can be classified into two types: non-electrochemical and electrochemical measurements.…”