INVESTIGADORES
VAZQUEZ marcela Vivian
congresos y reuniones científicas
Título:
Silicate Ions as Inhibiting Agents for Reinforcement Steel. 30 de Agosto al 4 de septiembre 2020.
Autor/es:
MONTES, FRANCISCO; ROLANDI, ANA CLARA; FRONTINI, MARIA; VAZQUEZ, MARCELA; VALCARCE, MARIA BEATRIZ
Reunión:
Congreso; 71st Annual Meeting de la International Society of Electrochemistry, Belgrade Online.; 2020
Institución organizadora:
International Society of Electrochemistry
Resumen:
Reinforced concrete is a reliable building material due to many excellent properties such as strength and durability. However, marine environments and chloride-contaminated aggregates accelerate deterioration and failure[1]. Inorganic inhibitors are frequently considered to mitigate steel corrosion [2,3]. In this work, silicate ions were tested as corrosion inhibitors in concrete pore simulating solutions contaminated with chloride ions. The electrochemical evaluation included cyclic voltammetry and polarization curves. Weight loss tests were implemented to follow the inhibitor performance over long exposure times. Micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to investigate the composition of the surface film.Steel is tested in an alkaline solution simulating the composition of pore solutions in concrete (pH 13) contaminated with 0.3 mol/L chloride ion, which also contains 0.3 mol/L silicate ion (Cl-PSS-Inh). Compared to Cl-PSS, the improvement in behavior and the difference in response when silicate ions are present is clear from the results of all the techniques used to evaluate the electrodes.Anodic polarization curves show no sign of pitting or any form of localized corrosion and very low passive current densities when silicate ions are present in solution. These results are promising in terms of the ability of these inorganic ions to be used as corrosion inhibitors.When chloride and silicate ions are present simultaneously in an Inhibitor/Chloride = 1 ratio, complete inhibition of the localized attack is observed after 60 days of immersion.Cyclic voltammograms and XPS spectra indicate that the presence of silicate ions affects the composition of the passive film (see Figure 1). However, further study is needed to understand the mechanism of action of silicate ions as inhibitors and to explore their effectiveness when used in mortars, concrete or to pre-treat the steel bars.