A multiphase micromechanical model for unsaturated concrete repaired by electrochemical deposition method with the bonding effects

2018 ◽  
Vol 27 (9) ◽  
pp. 1307-1324 ◽  
Author(s):  
Qing Chen ◽  
Zhengwu Jiang ◽  
Hehua Zhu ◽  
JW Ju ◽  
Zhiguo Yan ◽  
...  
Keyword(s):  
Transition Zone ◽  
Electrochemical Deposition ◽  
Micromechanical Model ◽  
Interfacial Transition Zone ◽  
Deposition Method ◽  
Viscosity Effects ◽  
Electrochemical Deposition Method ◽  
Consistent Method ◽  
Differential Scheme ◽  
Multiphase Composite

Most concrete structures repaired by the electrochemical deposition method are not fully saturated and the healing interfaces are not always perfect in reality. To demonstrate these issues, micromechanical models are presented for unsaturated concrete repaired by electrochemical deposition method with the healing interfacial transition zone based on our latest work. The repaired unsaturated concrete is represented as a multiphase composite made up of the water, unsaturated pores, intrinsic concrete, deposition products and the healing interfacial transition zone between the latter two components. The equivalent particle, matrix and composite for repaired unsaturated concrete are obtained by modifying the differential-scheme and the generalized self-consistent method. Modifications are utilized to rationalize the differential-scheme based estimations by taking into the water (including further hydration and viscosity effects), interfacial transition zone and the shapes of the pores into considerations. Furthermore, our predictions are compared with those of the existing models and available experimental results, thus illustrating the feasibility and capability of the proposed micromechanical framework.

Micromechanical framework for saturated concrete repaired by the electrochemical deposition method with interfacial transition zone effects

2016 ◽  
Vol 26 (2) ◽  
pp. 210-228 ◽  
Author(s):  
Qing Chen ◽  
Zhengwu Jiang ◽  
Hehua Zhu ◽  
J Woody Ju ◽  
Zhiguo Yan
Keyword(s):  
Transition Zone ◽  
Electrochemical Deposition ◽  
Effective Properties ◽  
Micromechanical Model ◽  
Interfacial Transition Zone ◽  
Particle Interactions ◽  
Deposition Method ◽  
Consistent Model ◽  
Electrochemical Deposition Method ◽  
Saturated Concrete

An improved micromechanical framework with interfacial transition zone (ITZ) effects is proposed for saturated concrete repaired by electrochemical deposition method (EDM) based on our recent studies. A multiphase micromechanical model with ITZs is proposed based on the material microstructure and a new multilevel homogenization scheme with inter-particle interactions is employed to predict the effective properties of repaired concrete considering the ITZ effects. The equivalent particle, composed by the water, deposition product and ITZ, is obtained by modifying the generalized self-consistent model. The mechanical properties of the healed concrete are calculated by micromechanical homogenization considering the inter-particle interactions. Moreover, modification procedures considering the ITZ effects are presented to attain the properties of repaired concrete in the dry state. To demonstrate the feasibility of the proposed micromechanical model, predictions in this study are compared with those of the existing models and the experimental data. Finally, the influences of ITZ on the equivalent particle and repaired concrete are discussed based on the proposed micromechanical framework.

Differential-scheme based micromechanical framework for unsaturated concrete repaired by the electrochemical deposition method

2016 ◽  
Vol 228 (2) ◽  
pp. 415-431 ◽  
Author(s):  
Qing Chen ◽  
Zhengwu Jiang ◽  
Zhenghong Yang ◽  
Hehua Zhu ◽  
J. Woody Ju ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Deposition Method ◽  
Electrochemical Deposition Method ◽  
Differential Scheme

scholarly journals An Improved Micromechanical Framework for Saturated Concrete Repaired by the Electrochemical Deposition Method considering the Imperfect Bonding

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Qing Chen ◽  
Zhengwu Jiang ◽  
Hehua Zhu ◽  
J. Woody Ju ◽  
Zhiguo Yan ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Effective Properties ◽  
Healing Process ◽  
Micromechanical Model ◽  
Deposition Method ◽  
Imperfect Bonding ◽  
Consistent Model ◽  
Electrochemical Deposition Method ◽  
Model Predictions ◽  
Saturated Concrete

The interfaces between the deposition products and concrete are not always well bonded when the electrochemical deposition method (EDM) is adopted to repair the deteriorated concrete. To theoretically illustrate the deposition healing process by micromechanics for saturated concrete considering the imperfect interfaces, an improved micromechanical framework with interfacial transition zone (ITZ) is proposed based on our recent studies. In this extension, the imperfect bonding is characterized by the ITZ, whose effects are calculated by modifying the generalized self-consistent model. Meanwhile, new multilevel homogenization schemes are employed to predict the effective properties of repaired concrete considering the ITZ effects. Moreover, modification procedures are presented to reach the properties of repaired concrete with ITZs in the dry state. To demonstrate the feasibility of the proposed micromechanical model, predictions obtained via the proposed micromechanical model are compared with those of the existing models and the experimental data, including results from extreme states during the EDM healing process. Finally, the influences of ITZ and deposition product on the healing effectiveness of EDM are discussed based on the proposed micromechanical model.

Stochastic micromechanical predictions for the probabilistic behavior of saturated concrete repaired by the electrochemical deposition method

2019 ◽  
Vol 29 (3) ◽  
pp. 435-453 ◽  
Author(s):  
Qing Chen ◽  
Hehua Zhu ◽  
J Woody Ju ◽  
Zhiguo Yan ◽  
Zhengwu Jiang ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Mechanical Performance ◽  
Effective Properties ◽  
Healing Process ◽  
Micromechanical Model ◽  
Maximum Entropy Principle ◽  
Deposition Method ◽  
Electrochemical Deposition Method ◽  
Entropy Principle ◽  
Saturated Concrete

A stochastic micromechanical framework is proposed to quantitatively characterize the probabilistic behavior of the mechanical performance of the saturated concrete healed by the electrochemical deposition method. Micromechanical model for the healed saturated concrete is presented based on the material microstructures, and new multilevel homogenization procedures are proposed to quantitatively predict the effective properties of the repaired concrete considering the inter-particle interactions. The evolutions of the deposition products are characterized by non-stationary random process, which is represented by Karhunen–Loeve approximations with limited random variables. The probabilistic behavior for the effective properties of the repaired concrete is reached by incorporating the maximum entropy principle and Monte Carlo simulations. The predictions obtained by the proposed stochastic micromechanical framework are then compared with the available experimental data, existing models, and commonly used probability density functions, which indicate that the presented stochastic micromechanical framework is capable of describing the electrochemical deposition method healing process, considering the inherent randomness of the material microstructures. Finally, the influences of the deposition products on the probabilistic behavior of the repaired concrete are discussed on the basis of the proposed models.

Modulating the surface states of electric field assembled CuO nanowires by electrochemical deposition method

2009 ◽  
Vol 95 (8) ◽  
pp. 083107 ◽  
Author(s):  
Lixiang Wang ◽  
Gang Cheng ◽  
Xiaohong Jiang ◽  
Shujie Wang ◽  
Xingtang Zhang ◽  
...  
Keyword(s):  
Electric Field ◽  
Electrochemical Deposition ◽  
Surface States ◽  
Deposition Method ◽  
Cuo Nanowires ◽  
Electrochemical Deposition Method

Electrochemical deposition induced continuum damage-healing framework for the cementitious composite

2021 ◽  
pp. 105678952199187
Author(s):  
Hehua Zhu ◽  
Qing Chen ◽  
J Woody Ju ◽  
Zhiguo Yan ◽  
Zhengwu Jiang
Keyword(s):  
Electrochemical Deposition ◽  
Planck Equation ◽  
Healing Time ◽  
Aqueous Environment ◽  
Continuum Damage ◽  
Deposition Method ◽  
Cementitious Composite ◽  
Current Conservation ◽  
Electrochemical Deposition Method ◽  
Damage Healing

The electrochemical deposition method is a promising approach to repair the deteriorated concrete in the aqueous environment. In this paper, a continuum damage-healing framework is presented for the electrochemical deposition method based on the multi-field coupling growth process of the electrochemical deposition products. The ion transportation and the electrode reactions are characterized by employing the Nernst-Planck equation and the current conservation equation. The level set method is adopted to capture the growth of the deposition products. Based on the deposition process, a new empirical healing law is presented, with which a new continuum damage-healing framework is presented for electrochemical deposition method. Numerical examples are conducted by applying the presented framework to the damaged cementitious composite under the tensile loadings. The presented framework is compared with the classic continuum damage-healing theory and the experimental data. The results show that the presented models can describe the electrochemical deposition method induced damage-healing for the cementitious composite. Furthermore, the effects of the healing time, the solution concentration and the external voltage on the damage-healing behaviors are investigated based on our proposed framework.

scholarly journals Preparation of Nanoparticle Porous-Structured BiVO4 Photoanodes by a New Two-Step Electrochemical Deposition Method for Water Splitting

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 136
Author(s):  
SocMan Ho-Kimura ◽  
Wasusate Soontornchaiyakul ◽  
Yuichi Yamaguchi ◽  
Akihiko Kudo
Keyword(s):  
Water Splitting ◽  
Electrochemical Deposition ◽  
Synthesis Method ◽  
Stoichiometric Ratio ◽  
Deposition Method ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
Xrd Pattern ◽  
Conversion Reaction ◽  
Electrochemical Deposition Method

In the synthesis method of a BiVO4 photoanode via BiOI flakes, a BiOI film is formed by electrochemical deposition in Step 1, and a vanadium (V) source solution is placed by drop-casting on the BiOI film in Step 2. Following this, BiVO4 particles are converted from the BiOI–(V species) precursors by annealing. However, it is challenging to evenly distribute vanadium species among the BiOI flakes. As a result, the conversion reaction to form BiVO4 does not proceed simultaneously and uniformly. To address this limitation, in Step 2, we developed a new electrochemical deposition method that allowed the even distribution of V2O5 among Bi–O–I flakes to enhance the conversion reaction uniformly. Furthermore, when lactic acid was added to the electrodeposition bath solution, BiVO4 crystals with an increased (040) peak intensity of the X-ray diffractometer (XRD) pattern were obtained. The photocurrent of the BiVO4 photoanode was 2.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) under solar simulated light of 100 mW/cm2 illumination. The Faradaic efficiency of oxygen evolution was close to 100%. In addition, overall water splitting was performed using a Ru/SrTiO3:Rh–BiVO4 photocatalyst sheet prepared by the BiVO4 synthesis method. The corresponding hydrogen and oxygen were produced in a 2:1 stoichiometric ratio under visible light irradiation.

Stochastic micromechanics-based investigations for the damage healing of unsaturated concrete using electrochemical deposition method

2020 ◽  
Vol 29 (9) ◽  
pp. 1361-1378 ◽  
Author(s):  
Q Chen ◽  
HH Zhu ◽  
JW Ju ◽  
HX Li ◽  
ZW Jiang ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Effective Properties ◽  
Healing Process ◽  
Deposition Method ◽  
Computationally Efficient ◽  
Concrete Material ◽  
Aspect Ratios ◽  
Micro Cracks ◽  
Electrochemical Deposition Method ◽  
Damage Healing

The (micro-) cracks or (micro-) voids will lead to the damage of concrete material. A stochastic micromechanical framework is proposed to investigate the damage healing of the unsaturated concrete with the electrochemical deposition method. Stochastic micromechanical representations are presented based on the material’s random microstructures. Differential scheme-based multilevel homogenization procedures are proposed to quantitatively predict the effective properties of the repaired concrete. The probability density functions are obtained for the material’s effective properties with an efficient stochastic simulation framework, which is composed of the univariate approximation for the multivariate function, Newton interpolations and Monte Carlo simulations. Numerical examples are employed to verify the proposed stochastic micromechanical framework, which indicates that the presented framework is computationally efficient and capable of describing the electrochemical deposition method healing process for the unsaturated concrete considering the material’s inherent randomness. Finally, the influences of the saturation degrees and the equivalent aspect ratios on the probabilistic behavior of the repaired concrete are discussed on the basis of the proposed models.

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