Abstract
ABSTRACT The method of measuring the corrosion potential is used as an electrochemical tool for helping the monitoring of the corrosion of reinforcements of concrete structures. As a criterion for evaluating results it is common to use intervals of corrosion potential and their correlation with corrosion probability, as precognizes ASTM C 876:2015. With this criterion, it is possible to establish an overview of the thermodynamic situation of corrosion in the structure or in the test specimen in laboratory. However, the method is influenced by several factors related with the concrete, the environment and with procedures adopted at the moment of executing the readings. Aiming to provide information to guide the technical and scientific environment regarding the right use of this type of non-destructive testing, the objective of this work is to evaluate some possible factors influencing the reading of corrosion potential, such as: moisture content of the concrete, water/cement ratio, thickness of the concrete cover and degree of contamination by chlorides. Results indicate that moisture and degree of contamination of the concrete by chloride ions had a tendency of making the corrosion potential more electronegative. Besides, it was verified that the influence of the cover is different for the case of contaminated concrete (1% of chlorides by mass of cement) and not contaminated with chlorides: the influence of the thickness of the cover, in the case of concrete contaminated by chlorides, was inversely proportional, in other words, the greater the cover thickness is, the less electronegative the value of the corrosion potential will be. On the other hand, in cases of concretes without chlorides, the effect of the cover thickness in the readings or corrosion potential was irrelevant. All this information was proved with 95% of statistical significance.
Highlights
Corrosion of concrete reinforcements is one of the possible mechanisms of degradation reducing the resistant capacity of reinforced concrete structures
It is possible to observe that the corrosion potential is more negative for greater moisture contents, as evidenced by Elsener et al [7] and Leelalerkiet et al [33]; in other words, corrosion potentials at 70 days measured in the test specimens that were in humid environment are more negative than corrosion potentials at 98 days, when the test specimens had a smaller moisture content
The interaction between moisture content and corrosion potential is significant and this fact was evidenced by means of variance analysis ANOVA (Table 4), where the value of F calculated is higher than the F critical tabulated for 95% of significance
Summary
Corrosion of concrete reinforcements is one of the possible mechanisms of degradation reducing the resistant capacity of reinforced concrete structures. According to Andrade & Alonso [1] and Assouli et al [2], the open circuit corrosion potential and electrical resistivity are the most common techniques for evaluating the corrosion of reinforcements, even if they are merely qualitative techniques evaluating the thermodynamics of the process, not providing data about the kinetics of the phenomenon Despite this affirmation being more than 10 years old, the method of corrosion potential continues to be one of the more common electrochemical tools for helping the inspection, monitoring and diagnostic of the corrosion of the reinforcements of concrete structures [3], being cited as a method of monitoring in inspection works in the field as recorded in the following studies: Andrade & Alonso [1]; Liam et al [4]; Helene [5]; Broomfield et al
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
