A discussion on the order of magnitude of corrosion current density in reinforcements of concrete structures and its link with cross-section loss of reinforcement

Abstract

This paper deals with the determination of the corrosion current density in chloride-induced corrosion in reinforced concrete structures. Because the corrosion of steel bars is generally localized, calculations of the densities of corrosion current need to take the real surface areas of anodic zones into account. Nowadays, in the lab or on site, the calculation of densities of corrosion are based on arbitrary steel surface areas, which merge anodic and cathodic zones. As a result, the order of magnitude of corrosion current density is not correct; it is underestimated. A second aspect of the paper is the relationship between corrosion current density and the prediction of service life in RC structure when including a part of the propagation phase. The consequences of the corrosion current density on mechanical properties such as corrosion-induced cracking or load-bearing capacity must consider that anodic areas grow both laterally and in-depth.

Influence of Recycled High-Density Polyethylene Fibers on the Mechanical and Electrochemical Properties of Reinforced Concrete

“…It can be noticed that the samples with long fibers present high values of icorr between 1 and 10 µ A/cm 2 , suggesting severe corrosion in the metal; similar results have been found by other authors [75]. This fact may seem to be a considerable loss of the reinforcement section; however, the "localized" corrosion mechanism in the L.I results leads to a maximum activity at the edges of the anodic area, and as a result, the anodic area extends in length instead of in depth [76]. As time progresses, the samples with long fibers decrease their icorr values to less than 1 µ A/cm 2 and 0.5 µ A/cm 2 , suggesting a high to negligible corrosion.…”

Chloride-induced corrosion of steel in concrete—insights from bimodal neutron and X-ray microtomography combined with ex-situ microscopy

“…While the processes related to classical pitting, mentioned above, may still apply for localized corrosion in concrete, additional factors play a role and cause the growth to occur in lateral direction rather than primarily in depth. In this regard, authors have previously argued that the anodic and cathodic current distributions may cause the pit to grow outwards [ 44 , 45 ]. However, this explanation based on differences in local current density may apply to pitting of a metal in an electrolyte similarly as to localized corrosion of steel in concrete, and thus, it may not fully explain the experimental observation of the shallow pit morphology.…”

Nonlinear finite element modeling of bridge piers under the combined effect of corrosion, freeze–thaw cycles, and service load

“…The analysis was performed from climatic data ranging from 1953 to 2013. According to Faraday's law, assuming a high corrosion level, a corrosion current density of 50 leads to stage 1 of corrosion‐induced damage after 10 years of service (longitudinal mass loss of 5%, tie mass loss of 10%, and subsequent deterioration effects on concrete and bond‐slip response 19 ), leads to stage 2 after 40 years (longitudinal mass loss of 20%, tie mass loss of 40%, and subsequent deterioration effects on concrete and bond‐slip response 19 ), and leads to stage 3 after 60 years (longitudinal mass loss of 30%, tie mass loss of 60%, and subsequent deterioration effects on concrete and bond‐slip response 19 ) in Montreal. A cycle of −18°C to 4°C 23 over the last 10, 40, and 60 years in Montreal was observed to lead to 22, 113, and 165 FTCs, respectively (Figure 5).…”