Pulverized-Fuel Ash Concrete: Carbonation-Induced Reinforcement Corrosion Rates.

Dhir, Ravindra K.; Jones, M. R.; McCarthy, M. J.

doi:10.1680/istbu.1992.20293

Cited by 27 publications

(15 citation statements)

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“…This knowledge has also entered textbooks [29] and to some extent standards (Table 1). A number of studies showed that the instantaneous corrosion rate in carbonated concrete increases exponentially with the relative humidity in the concrete [42][43][44][45][46]. This relationship was recently explained by the dual role of the pore structure of the cementitious medium surrounding the embedded steel [37].…”

Section: Corrosion Rate 421 Fundamental Processes Controlling the Cmentioning

confidence: 99%

Corrosion of steel in carbonated concrete: mechanisms, practical experience, and research priorities – a critical review by RILEM TC 281-CCC

et al. 2020

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Carbonation of concrete is generally assumed to lead to reinforcing steel corrosion. This mindset has long dictated the research priorities surrounding the developments towards new, low-emission binders. Here, by reviewing documented practical experience and scientific literature, we show that this widely held view is too simplistic. In fact, there are many cases from engineering practice where carbonation of the cementitious matrix surrounding the steel did not lead to noticeable corrosion or to corrosion-related damage at the level of a structure. The influencing factors that can, however, lead to considerable corrosion damage are identified as the moisture state, the microstructure of the carbonated concrete, various species that may be present – even in minor amounts – in the concrete pore solution, and the cover depth. The circumstance that a reduced pH alone is not sufficient to lead to significant steel corrosion in concrete seriously challenges the established approach of assessing the durability performance based on carbonation testing and modeling. At the same time, this circumstance offers great opportunities for reducing the environmental impact of concrete structures with low-emission binders. To realize these opportunities, the focus in research and engineering should shift from studying carbonation to studying corrosion of steel in carbonated concrete.

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Section: Corrosion Rate 421 Fundamental Processes Controlling the Cmentioning

confidence: 99%

Corrosion of steel in carbonated concrete: mechanisms, practical experience, and research priorities – a critical review by RILEM TC 281-CCC

et al. 2020

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“…Interestingly, already in the 1950s, Romanoff, in the conclusions of an extensive report describing a 17 years long study on corrosion of steel in soil 7 , stated: "(…) it appears that not enough attention was given to the amount of moisture at the [steel] surface (…) Water now appears to be important by itself, aside from its effects on the availability of atmospheric oxygen". While Romanoff already seems to have suspected such an influence, and while also other studies later attributed key importance to the water distribution at the electrode surface [21][22][23][24][25] , thorough mechanistic explanations have not been provided until today.…”

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confidence: 99%

Kinetics of electrochemical dissolution of metals in porous media

2019

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Metals embedded in porous media interact electrochemically with the liquid phase contained in the pores. A widespread form of this, adversely affecting the integrity of engineered structures, is corrosion of steel in porous media or in natural environments. While it is well-documented that the rate of this electrochemical dissolution process can vary over several orders of magnitude, understanding the underlying mechanisms remains a critical challenge hampering the development of reliable predictive models. Here we study the electrochemical dissolution kinetics of steel in meso-to-macro-porous media, using cement-based materials, wood, and artificial soil as model systems. Our results reveal the dual role of the pore structure, that is, the influence on the electrochemical behavior through transport limitations and an area-effect, which is ultimately due to microscopic inhomogeneity of the metal-porous material interface. We rationalize the observations with the theory of capillary condensation and propose a material-independent model to predict the corrosion rate.

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“…This increase in corrosion rate with clinker substitution is very significant (more 288 than a factor 5) for partially or fully immersed conditions [25][26][27]68]. In the humidity range 289 from 95% RH [34,59]…”

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confidence: 99%