A MODIFIED IMPRESSED CURRENT CIRCUIT FOR CATHODIC PROTECTION TO ACHIEVE A BETTER POTENTIAL CONTROL AT THE STEEL-MORTAR INTERFACE

摘要

A modified impressed current circuit is proposed to attain potential control, within narrow limits, in electrolytic cells with cathodically polarized steel-mortar specimens. A description of the circuit is given as well as a procedure to prepare the specimens and the full design of the cell to carry out studies on cathodic protection under total immersion conditions. These conditions were selected to avoid the uncertainties that arise from changes in the electrolyte resistance when concrete is not immersed. The designed circuit is suitable to keep the polarization potential within narrow limits and is a good replacement of the potentiostatic circuit, which would be expensive if a large number of cells had to be polarized. Furthermore, the cell design suggested is considered to be helpful to study particular variables such as the variation in bond strength caused by the applied cathodic protection, the effect of reactive aggregates present in the mortar, etc.