Chloride-induced corrosion of steel rebars in simulated pore solutions of alkali-activated concretes
The passivation and chloride-induced depassivation of steel rebars immersed in varying alkaline environments (0.80 M, 1.12 M and 1.36 M NaOH solutions), simulating the pore solutions of low-Ca alkali-activated concretes, were investigated using a range of electrochemical techniques. The passive film...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/343883 |
| Acceso en línea: | http://hdl.handle.net/10261/343883 https://api.elsevier.com/content/abstract/scopus_id/85027856693 |
| Access Level: | acceso abierto |
| Palabra clave: | Alkali activated cement (D) Chloride (D) Corrosion (C) Pore solution (B) Electrochemical properties (C) http://metadata.un.org/sdg/9 Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Sumario: | The passivation and chloride-induced depassivation of steel rebars immersed in varying alkaline environments (0.80 M, 1.12 M and 1.36 M NaOH solutions), simulating the pore solutions of low-Ca alkali-activated concretes, were investigated using a range of electrochemical techniques. The passive film on the steel rebars was complex in chemical makeup, composed of Fe–hydroxides, oxy-hydroxides and oxides. An increased degree of passivation of the rebars was observed when exposed to solutions with higher hydroxide concentrations. The critical chloride level ([Cl−]/[OH−] ratio) required to induce depassivation of steel was strongly dependent on the alkalinity of the pore solution, and was found to be 0.90, 1.70 and 2.40 for 0.80 M, 1.12 M and 1.36 M NaOH solutions, respectively. These values all correspond to a constant value of [Cl−]/[OH−]3 = 1.25, which is a novel relationship to predict the onset of pitting, interlinking chloride concentration and the solubility of the passive film. |
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