Usability of Conductive based Cement Anode for Impressed Current Cathodic Protection of Reinforced Concrete Structures

Abstract

The service life of an impressed current cathodic protection (ICCP) system for reinforced concrete structures is primarily determined by the serviceability of the anode used. In this paper, a long-term galvanostatic polarization test was conducted to investigate the serviceability and durability of a cement conductive anode, and then the microcosmic surface topography and the phase components of the polarized and unpolarized cement anodes were analysed. The results indicate that the long-term operation of the cement anode can cause the formation of Friedel's salt, the reaction of calcium hydroxide crystals, the electrochemical oxidation of the conductive admixtures, and the damage to the interface between the primary anode and the cement conductive anode. Additionally, the electrochemical oxidation of conductive admixtures added into the cement anode is found to be the fundamental reason for the loss of the serviceability of the cement conductive anode, and the model predicting the life expectancy of the cement conductive anode is also presented.