Multiscale modeling of steel corrosion in concrete based on micropore connectivity

Ohno, Motohiro; Limtong, Pakpoom; Ishida, Tetsuya

doi:10.1016/j.jobe.2021.103855

Cited by 7 publications

(2 citation statements)

References 31 publications

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“…In this section, numerical simulations were conducted on the actual RC culvert exposed to natural environmental conditions, and it was shown that the multiscale chemo-hygral computational system can be applied to predict the long-term behavior of RC structures. Meanwhile, the actual corrosion current density should be determined by considering surrounding environments, such as relative humidity, oxygen, temperature, etc., and it can be calculated based on Evans diagram (Ohno et al 2022). In this research, however, constant corrosion current density was assumed to act on reinforcing bars to focus on investigating the effect of current density (i.e., corrosion speed) on the structural behavior of RC members.…”

Section: Analysis Results Of Long-term Behavior Of Rc Culvert Conside...mentioning

confidence: 99%

Multiscale Numerical Simulations of Static Shear and Long-Term Behavior of RC Members Considering Corrosion of Reinforcing Bars

Han

Ishida

Tsuchiya³

2022

ACT

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In this study, a finite element (FE) analysis is conducted to investigate the effects of corrosion in tensile reinforcement on the shear performance of reinforced concrete (RC) members. In this regard, a multiscale chemo-hygral computational system is adopted, and its rationality is verified by comparing the FE analysis results with the shear test results of corroded RC beams. Based on the verified FE model, a parametric analysis is performed to examine the static shear and long-term behaviors of RC members according to the corrosion damage. The analysis results show that when the tensile reinforcement is simply straight anchored in the member, the ratio of reduction in shear strength due to corrosion decreases with the shear span-to-depth ratio. Meanwhile, when the tensile reinforcement is fully anchored, the shear strength of the corroded member increases owing to the formation of arch action despite the occurrence of splitting cracks caused by corrosion, and this tendency is more prominent as the shear span-to-depth ratio decreases. In terms of the long-term behavior of corroded RC members, it is shown that as corrosion progresses gradually over time, failure occurs with a rapid increase in deflection, including at low sustained load levels.

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Section: Analysis Results Of Long-term Behavior Of Rc Culvert Conside...mentioning

confidence: 99%

Multiscale Numerical Simulations of Static Shear and Long-Term Behavior of RC Members Considering Corrosion of Reinforcing Bars

Han

Ishida

Tsuchiya³

2022

ACT

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“…Introduction of the additional source of humidity, particularly during the tests simulating dry environmental conditions, could considerably change the measurement results. In the paper [64] which described modelling of steel corrosion, moisture content of concrete was associated with the level of pore filling, and consequently with coverage of rebar surface with pore solution (Figure 14e). In the electrochemistry limiting the electrode surface is related to absorption of inert substances, where the degree of electrode covering is defined by the value θ.…”

Section: Assessment Of Benefits Of the Modified Testing Methodologymentioning

confidence: 99%

Corrosion Diagnostics Performed on Cores Drilled from Concrete Structures, Using the Laboratory Simulation of Temperature and Relative Humidity Impact

Jaśniok

2022

Applied Sciences

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This paper presents an improved procedure for conducting diagnostics tests on corrosion in reinforced concrete structures. This method consists in drilling cylindrical concrete cores with fragments of secondary steel reinforcement (e.g., spacer bars, stirrups, binders) from the selected areas of the structure. Then, a three-electrode system is arranged on those cylindrical cores under laboratory conditions. The fragment of steel rebar with concrete is used as the working electrode. Using the counter electrode in the form of a patented conductive coating applied on the core side wall with painting techniques and the graphite reference electrode placed in an opening made in the core near the reinforcement was the novelty of this method. Following the procedure, the occurrence of minimum and maximum corrosion rates in concrete is simulated in the climate chamber after determining, on the basis of historical weather data, extreme combinations of temperature, and relative humidity for a given structure. This method was verified in the diagnostics testing of two large reinforced concrete tanks for fresh water, and cement storage silos.

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Evaluation of Moisture Transport Properties Based on Modelling of Silane-based Impregnation Agent Effects on Concrete Surface Layer

Takahashi,

Miyake,

Ohno

et al. 2023

E3S Web Conf.

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It is now desirable to establish a technique for long-term prediction of the effects of silane-based impregnation agent on concrete structures exposed to various environments. To meet this requirement, the purpose of this study is set to establish the model to evaluate the effect of a silane-based impregnation agent on the waterproofing properties of cementitious materials based on microscopic mechanisms. Several mortar specimens were prepared with the silane-based impregnation agent, and moisture absorption and evaporation experiments were conducted. The results showed that the application of the agent was shown to effectively inhibit the penetration of moisture into the interior of the cementitious materials. The effect of the silane-based impregnation agent was modeled in a multiscale pore structure model by applying a microscopic water-repellent effect to the pores in which no pore water was present at the time of agent coating. The analysis with proposed model showed that, as in the experiment, the moisture supply was reduced by the application of the agent, whereas the amount of moisture loss remained almost the same with and without the agent. Moreover, the analysis quantitatively showed that the water content can continue to decrease with silane treatments, even under repeated wet-dry conditions.

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Multiscale modeling of steel corrosion in concrete based on micropore connectivity

Cited by 7 publications

References 31 publications

Multiscale Numerical Simulations of Static Shear and Long-Term Behavior of RC Members Considering Corrosion of Reinforcing Bars

Multiscale Numerical Simulations of Static Shear and Long-Term Behavior of RC Members Considering Corrosion of Reinforcing Bars

Corrosion Diagnostics Performed on Cores Drilled from Concrete Structures, Using the Laboratory Simulation of Temperature and Relative Humidity Impact

Evaluation of Moisture Transport Properties Based on Modelling of Silane-based Impregnation Agent Effects on Concrete Surface Layer

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