ISSN:
1572-8838
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Electrical Engineering, Measurement and Control Technology
Notes:
Abstract A reproducible procedure has been developed to study the cyclic voltammetry of iron electrodes embedded in cured Portland cement: It is recommended that suchin situ measurements be used in preference to those in simulated pore solutions. This method, which should prove useful as a means of studying the corrosion of reinforced concrete, is described in detail. The usefulness of the method has been demonstrated by means of a series of brief preliminary studies. Specifically, studies on the effects of sweep rate, chloride additions, and the role of Ca(OH)2 in the passivation of iron in alkaline solutions, were performed. The sweep rate behavior of the passivation peak in cement was consistent with that predicted by a pore diffusion model. As expected, the chloride additions were found to disrupt the passivity, as evidenced by a general increase in the voltammetric currents and the electrode resistance, as well as by the appearance of a new anodic peak in the normally passive potential regime. The results indicated that, although the reaction mechanism is similar in cement to that in aqueous alkaline solution, the passivity of iron is enhanced in cement, relative to that observed in aqueous KOH or NaOH solutions. This is shown to be related to the presence of Ca(OH)2 in the cement pore solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01007934
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