Chloride induced reinforcement corrosion in cracked and coated concrete: From experimental studies to time‐dependent numerical modeling

摘要

> The aim of the presented research work is to analyze and numerically describe the time‐dependent anode kinetics of steel in cracked reinforced concrete, which is exposed to de‐icing salts for a short time (one winter period) before a concrete coating is applied. In experimental studies the mechanism of chloride induced macro cell corrosion is investigated by measuring essential corrosion parameters. Therein, the surface coating finally leads to a halt of macro cell current for all actively corroding samples. The anode kinetics is identified as the decisive control factor leading to a stop of corrosion. In order to transfer the laboratory results onto real component geometries, numerical methods are used. These require a detailed workup of the anodic reaction kinetics, since the time‐dependent characteristics of the anode, identified in the experimental program, must be taken into account in the numerical simulations. For this, specific integral polarization resistances ( r _pi,a ) are determined as an adequate approach which also allow for an extrapolation of the anode kinetics beyond the experimental investigations. The main findings of the numerical study are that geometrical and electrochemical influences, except the driving potential, are eventually superimposed by increasing r _pi,a . As in the experimental studies, r _pi,a is again identified as the dominant control factor stopping corrosion.