THE PITTING CORROSION RESISTANCE OF HIGH-GRADE CORROSION-RESISTANT REBAR IN SIMULATED CONCRETE PORE SOLUTIONS

Author(s): W. Sun, J.J. Shi and J.Y. Jiang
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 38-49
Total Pages: 961
Language : English

Abstract: To properly evaluate the pitting corrosion performance of high-grade corrosion-resistant rebar (HCR) specimen in concrete when exposed to chloride environments, the pitting corrosion resistance of HCR and regular low-carbon rebar (LC) specimens in simulated concrete pore solutions (SCPS) with various chloride concentrations (0.1 M, 0.3 M and 1.0 M) was investigated by means of cyclic potentiodynamic polarization (CPP) curves. The effects of passive film for both rebar specimens pre-passivated in SCPS for 10 days and immersion time (stabilized for 1 hour or 24 hours before CPP tests) on the pitting corrosion resistance were also discussed.
The results of EIS and CPP curves reveal that the pre-passivation exerts a more pronounced effect on the formation and stability of passive film as well as pitting corrosion resistance for LC specimens in comparison to HCR specimens, although the corrosion resistance of passive film formed on the surface of HCR is higher than that of LC after 10 days of passivation. However, the pitting corrosion resistances of HCR specimens are superior to that of LC specimens in chloride-containing SCPS, especially with higher NaCl content, possibly owing to the underlying inhibiting effect of Cr-enriched dense inner rust layer on the development of pits on the surface of HCR specimens. In addition, it is also found that the immersion time also affects the pitting corrosion resistance of both LC and HCR specimens, particularly in SCPS with high NaCl content.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00