Numerical simulations of an operative measurement mode of polarisation resistance adapted for evaluating the corrosion of reinforced concrete on cooling towers

摘要

This paper summarises the results obtained from the numerical simulations of an operative measurement mode of polarisation resistance adapted for the evaluation of corrosion of reinforced concrete on cooling towers. The measurement of polarisation resistance consists of a local electrochemical nondestructive technique, suggested for the accurate evaluation of the corrosion of steel reinforcements. An original operative measurement mode of resistance of polarisation is proposed, adapted for cooling towers submitted to corrosion due to carbonation. The probe consists of a ring counter-electrode and a reference electrode and the measurement is realised on a single point on the surface of the structure (figure 1). By means of numerical experimentations, relationships are established between the measurement performed at the surface of the concrete above the reinforcement and the actual value of potential on the steel which is really of concern for the diagnosis of the structure. Abacus and correction laws are built involving the different parameters which influence the measurement such as the concrete cover of the steel rebar, the resistivity of concrete and the intensity of the injected current from the counter electrode.