Influencing Factors of Steel States in Concrete Based on Electrochemical Impedance Spectroscopic Measurements

Round 1

Reviewer 1 Report

Using the impedance technique, the author attempted to detect corrosion, and the article was nicely written, but a few suggestions were made to improve it.

Add recent references, primarily by "Ruipan Wang", on impedance analysers.

A comparative result is highly appreciable in terms of experiments, i.e., resistivity, half-cell potential, LPR, or Accelerated corrosion test. 

Reproducibility of the same article by others is very critical. Provide the details clearly. The chemical composition of cement and properties of materials used.

The comparative results between samples, i.e. two different types of concrete, would provide a better understanding

Provide experimental setup pictures and clearly explain using them.

Pictorial representation of experimental procedure is highly appreciable.

In terms of electrical circuits, the article elaborates properly. However, the presentation of results can still be improved. Even graphs can be presented more elaborately.  

The article was very interesting to read, and it can be improved further using pictorial representation.

 

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

In this study, factors affecting the state of steel in concrete were investigated based on spectroscopic measurements of electrochemical impedance. For this, EIS measurements were made for the active/passive states of the steel in the concrete under various conditions in order to minimize the variable errors that may be caused by the operators. Considering the fact that the research carried out is very important for the literature, it was concluded that the paper should be published after the minor revisions mentioned below were reviewed by the authors. 

1--In the Introduction part, within the scope of the method discussed for the investigation of the corrosion rate, although the authors made a detailed literature search in terms of the effective parameters determined, there was no discussion that the deterioration of the reinforcement, which is the main concern of corrosion, is not homogeneous. Within the scope of this main-title, it is suggested that some discussion be made for non-homogeneous rebar corrosion in order to increase the original value of the paper. 

2--It is thought that a schematic representation should be added to the paper for the polarization technique, which is defined within the scope of the Background of EIS corrosion measurements main-heading and expressed with an empirical model.

In the paper, it would be more accurate to revise the word "imaginary parts", which is generally used for impedance measurement parts, as "fictitious parts". 

3--The authors need to check the correctness of the electrical circuit C-2 in Figure 2 for the presence of Warburg impedance (W).

In order for the notations and abbreviations reported in the paper for both equations 1 and 2, for Figure 2 and for Figure 3 to be followed more accurately, an additional sub-title should be created for this, where the paper is deemed appropriate by the authors. 

4--For the experimental work carried out in a very organized way, only the schematic of the concrete sample is reported by the authors in the paper. The paper does not contain any complementary schematic representations or flowcharts for the topic focused on by the authors regarding the experimental set-up. For the added value of the paper, a schematic illustration or flow chart for the experimental set-up should be included by the authors, whichever is appropriate. 

5--In Figure 4, the electrical impedance spectrum relations for the active and passive states are given, the axes (horizontal and vertical) of both graphs should be expressed with the same scale in order to make a better comparison of the experimental findings obtained. 

The previous note should also be taken into account in Figure 5, where electrical impedance spectrum relationships are given for active states at different pressures. 

6--For the notations and/or abbreviations in Figure 8, the suggested third note should be considered. In addition, in the second paragraph of this sub-title, the abbreviations defined in the text for the physical properties in Figure 8 should be checked by the authors. (for example, CEPConc should be revised as CPEConc, etc.)

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript is generally well written, and some suggestions are listed as follows: 

1. The paper including the corrosion sensory of concrete structures can be cited: Construction and Building Materials, 203, 146-163. Composites Communications, 23, 100563, 2021.

2. The electrical and sensory properties of cementitious materials under chloride environments can be briefly introduced in the second paragraph of Introduction: Cement and Concrete Composites, 126, 104379, 2022.  

3. How many working electrodes here? You may briefly introduce. 

4. Can you simply explain the three-electrode configuration?  Why you chose this configuration. 

Author Response

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Author Response File: Author Response.docx