Non-uniform rust expansion for chloride-induced pitting corrosion in RC structures

3D simulation of localized steel corrosion in chloride contaminated reinforced concrete

“…In the case of chloride-induced steel corrosion in concrete, two kinds of electrochemical corrosion cells may coexist during the corrosion propagation stage: microcells leading to uniform/generalized corrosion and macrocells causing pitting/localized corrosion [13,20]. The coupled micro-and macro-cell corrosion behavior is illustrated in Fig.…”

“…15. For the extreme 2-D case (L = L a ), macrocell corrosion vanishes as the whole rebar circumference starts to corrode and microcell corrosion may finally dominate the corrosion process [13].…”

“…The values for geometric parameters are listed in Table 2 and the input material properties for numerical analysis are summarized in Table 3. Selection of these parameters are described in the author's published work and the references cited therein [13]. Due to symmetry, only one quarter of the slab/girder section is considered in the numerical analysis.…”

“…Therefore, the average corrosion current densities (i a mic , i a mac and i a total ) have been obtained from the electrochemical corrosion analysis. Assuming that i corr (A/m 2 ) is the total corrosion current density that flows through the corroding steel, the corrosion attack penetration (reinforcing steel radius reduction) x p (m) around the rebar circumference can be approximately estimated as [13] x p ðh; tÞ ¼…”

“…Nonetheless, numerical and experimental results have shown that macrocell corrosion may significantly increase the iron dissolution rate around localized anodes. The formation of pitting corrosion are found to be mainly caused by macrocell corrosion circulating around rebar circumference and along reinforcement length [12][13][14][15].…”