Silicate and Portland cement based compositions for protection against electrical corrosion

Abstract

AbstractConductive silicate compositions and compositions based on Portland cement for screen protection against electrical corrosion of reinforced concrete structures and buildings on electrified direct current railways are theoretically and experimentally substantiated. The compositions are used as putty or plaster on structures to be protected. The resulting coating drains corrosive leakage currents from the rails through grounding. In these compositions, the component that provides electrical conductivity is dispersed graphite. Depending on the additional requirements for the coating, sodium silicate with sodium silicon fluoride or Portland cement are used as binders. It was established that in these compositions the silicate and cement components are conductors of the second kind, and graphite is the conductor of the first kind. Due to the imposition of an electric potential, the surfaces of dispersed graphite particles are divided into cathodic areas and anodic areas, where the graphite dissolves, therefore the resource of the composition is determined by the amount of electricity passed through. In addition, it was found that the electrophysical properties of the compositions are in antagonism with their rheological, physical‐mechanical, hydro physical properties, therefore, the development of their composition should be carried out by methods of compromise optimization. Formulations of compositions that have been tested in operational conditions have been developed.