Rem: Revista Escola de Minas
Print version ISSN 0370-4467
TOMMASELLI, Maria Aparecida Garcia; KURI, Sebastião Elias and MARIANO, Neide Aparecida. Impedance spectroscopy to evaluate the effect of sodium molybdate in concrete. Rem: Rev. Esc. Minas [online]. 2008, vol.61, n.3, pp. 397-402. ISSN 0370-4467. http://dx.doi.org/10.1590/S0370-44672008000300020.
The reinforced concrete has more and more arisen scientific and technological interest concerned mainly to its innovation and improvement either by the utilization of new materials or by the study of corrosion to avoid structure deterioration. In that way, the study of corrosion in reinforced concrete has been intensified but the biggest difficult is to detect the beginning of the corrosion in the steel. One of the reasons of the reinforced concrete degradation and afterwards the corrosion in the steel is its exposition to industrial environments. Thus, it is necessary to improve the performance of the structures, foreseeing its useful life and knowing the manners of prevention to minimize the corrosive process. There are methods to control the corrosion of the steel as the annexation of concrete inhibitors such as the sodium molybdate, an anodic inhibitor and not a toxic pollutant. In this work the efficacy of the sodium molybdate was evaluated with concentrations of 0, 1, 2 and 4% related to the cement mass, employing the electrochemistry impedance spectroscopy, simulating an acid atmosphere as an aggressive agent. The concentration of 4% in the inhibitor was the most efficient.
Keywords : Concrete; corrosion; impedance spectroscopy; sodium molybdate.