Effects of Temperature on Corrosion Behavior of Reinforcements in Simulated Sea-Sand Concrete Pore Solution

Round 1

Reviewer 1 Report

1. There is a grate improvement from the last review round. However, the introduction needs a second round of English editing.
2. The term desalination (line 23) is used for separating salt from water, in this context, fresh water wash, or similar term is more adequate.
3. Equation 2 – it should be mentioned that this relationship is true in the temperature range of the experiment. Do not comet for any temperature.
4. Line 167 - Error! Reference source not found

From the last review, the following comment was ignore: 8.          Figures 5, 6, and 8 and their corresponding tables 2, 3, and 4 – the value of R2 is meaningless for this work. You could use p-value. What is more important but missing is the confidence interval for the slopes (and intercept). This confidence interval with the corresponding slopes should be used in statistical test to decide whether it is one slope for all the chloride concentrations or temperatures. If it is the same slope, the slope should be calculated from all the data to receive better accuracy

Author Response

1. There is a grate improvement from the last review round. However, the introduction needs a second round of English editing.

Thanks for reviewer’s great suggestion. The English of introduction has been carefully proofread in the revised manuscript. This version should be much better than the previous one. Please see the details in revised manuscript.

2. The term desalination (line 23) is used for separating salt from water, in this context, fresh water wash, or similar term is more adequate.

The term desalination has been corrected as fresh water wash according to reviewer’s suggestion in Lines 23-24 of revised manuscript.

3. Equation 2 – it should be mentioned that this relationship is true in the temperature range of the experiment. Do not comet for any temperature.

The valid temperature range of Equation 2 has been marked in Lines 162-163 of revised manuscript.

4. Line 167 - Error! Reference source not found

The wrong presentation has been modified as Fig. 8(a) in Line 174 of revised manuscript.

5. From the last review, the following comment was ignore: 8.          Figures 5, 6, and 8 and their corresponding tables 2, 3, and 4 – the value of R2 is meaningless for this work. You could use p-value. What is more important but missing is the confidence interval for the slopes (and intercept). This confidence interval with the corresponding slopes should be used in statistical test to decide whether it is one slope for all the chloride concentrations or temperatures. If it is the same slope, the slope should be calculated from all the data to receive better accuracy.

Thanks for reviewer’s great comment. The Tables 2, 3 and 4 have been deleted and replaced as Figs 7, 9 and 12 according to reviewer’s comments in revised manuscript. The changing tendency of fitting parameters, including slopes and intercept, are discussed with average value and 95% confidence interval marked in the figures. As the descriptions of new figures are context related, please see the detailed revisions in the revised manuscript. Hopefully, this improvement could meet the reviewer’s requirement correctly.

Reviewer 2 Report

I thank the authors for the revision but still some work to be done. 

Authors need to show more work to justify and establish results.  

Furthermore, the literature review does not cover some of the key papers from the researchers like Dr. Raja Rizwan Hussain who has done significant work on the same topic. There could be some more researchers like Prof Arnaud from UNSW significant works on the same topic. Therefore, I have suggested further works for the authors.

Author Response

Thanks for reviewer’s great comments. More details of possibility distribution of fitting parameters were provided in Figs 7, 9 and 12 in revised manuscript for deepen understanding of fitting process. Besides, the related references presented by Dr. Raja Rizwan Hussain and Prof Arnaud have been introduced in introduction part as Refs. [13, 24-26] and [21-23], respectively, according to reviewer’s suggestion.

Reviewer 3 Report

The manuscript has an overall improvement, I suggest it should be publish in its present form.

Author Response

Thanks for reviewer’s recommendation.

Reviewer 4 Report

The research paper studies the effect of temperature on the chloride-induced corrosion behavior of reinforcing steel in simulated sea-sand concrete pore solution. 

It is a very actual and iteresting theme. I suggest to authors to make few corrections and additions in the manuscript before its publishing:
                  

1. Experimental program - You should explain why did you choose right the type HRB335 ribbed reinforcing steel with a diameter of Φ10 mm?
                        - line 73: references to RILEM TC 235 CTC is missing
                        - line 75 - lower index in H2O is missing, ratio 1:1 is by weight or by volume?
                        - line 107 - What does the range "-20~+20 mV" mean?

2. Results and analysis
    - line 158 - "°C" should be in brackets
    - line 167 - "Error! Reference source not found"

I suggest to authors also to think about the influence of sea-sand on the durability and strength of concrete in practise.

Author Response

The research paper studies the effect of temperature on the chloride-induced corrosion behavior of reinforcing steel in simulated sea-sand concrete pore solution. 

It is a very actual and interesting theme. I suggest to authors to make few corrections and additions in the manuscript before its publishing:

1. Experimental program - You should explain why did you choose right the type HRB335 ribbed reinforcing steel with a diameter of Φ10 mm?

The HRB335 ribbed reinforcing steel was chosen to represent the widely used reinforcing steel in practical engineering. This explanation has been added in Lines 71-72 of revised manuscript.
line 73: references to RILEM TC 235 CTC is missing.

Reference related to RILEM TC 235 CTC has been added as Ref. [27] in Line 75 of revised manuscript.
line 75 - lower index in H2O is missing, ratio 1:1 is by weight or by volume?

The lower index in H₂O has been modified. The ratio 1:1 was referred to ratio by volume. Please see the modified word in Line 77 of revised manuscript.
line 107 - What does the range "-20~+20 mV" mean?

The range "-20~+20 mV" means that the experiment of linear polarization was set to sweep at the range of -20~+20 mV. This specification has been added in Lines 109-110 of revised manuscript.

2. Results and analysis
  - line 158 - "°C" should be in brackets

The brackets have been added in Line 165 of revised manuscript.
    - line 167 - "Error! Reference source not found"

The wrong presentation has been modified as Fig. 8(a) in Line 174 of revised manuscript.

I suggest to authors also to think about the influence of sea-sand on the durability and strength of concrete in practise.

Thanks for reviewer’s value suggestion. The influences of sea-sand on the durability and strength are also one of our main research focuses in this series of research. A lot of measuring and modelling efforts have been done by our authors, such as previously published papers in Ref [1-3]. Therefore, we decide to exclude this part of knowledge in this paper and hope the experimental results presented in this paper could explain the effects of temperature on corrosion behavior of steel rebars in simulated pore solution.

[1] W. Liu, H. Cui, Z. Dong, et al., Carbonation of concrete made with dredged marine sand and its effect on chloride binding, Constr. Build. Mater., 120 (2016) 1-9.

[2] W. Liu, Y. Li, L. Tang, et al., Modelling analysis of chloride redistribution in sea-sand concrete exposed to atmospheric environment, Constr. Build. Mater., 274 (2021) 121962.

[3] Y.Q. Li, W. Liu, T.W. Mi, et al., Durability study of simulated seawater and sea-sand concrete under the combined effects of carbonation and chloride redistribution, Submitted to Cement and Concrete Composites, (2021).

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The manuscript in my assessment is poorly communicated. Furthermore, the motivation for conducting this research is not clear. I will not recommend publication of the manuscript in journal of Materials.

I would like to give some details: The problem that arises in this article that it does not give original results, the influence of temperature on corrosion has not been treated in a different way, this topic has already been discussed and treated previously, so no new results to publish. In addition sea sand is not allowed in concrete production.

Author Response

Respected Reviewers,

            We, the authors, have revised the manuscript in the light of your comments. We would like to thank you for your valuable suggestions and comments, which contributed to further elaboration of our manuscript. Please note that our responses (additions/modifications) are in bold words.

Regards,

The Authors

 

Reviewer 1:

The manuscript in my assessment is poorly communicated. Furthermore, the motivation for conducting this research is not clear. I will not recommend publication of the manuscript in journal of Materials.

Thanks for reviewer’s valuable comments. The research topic of this paper is the effect of temperature on corrosion behavior of reinforcements in chloride contaminated environment, i.e., in simulated concrete pore solution. It is indeed the topic presented in this paper is not very consistent with the previous paper published in Materials journal. However, we believe this study should be agreed with the expected topic in special issue of "Reinforced Concrete Structures for Durability and Corrosion Resistance". Hopefully, the reviewer could consider our revised manuscript again.

I would like to give some details: The problem that arises in this article that it does not give original results, the influence of temperature on corrosion has not been treated in a different way, this topic has already been discussed and treated previously, so no new results to publish. In addition sea sand is not allowed in concrete production.

Thanks for reviewer’s worthy comments. The figures and tables presented in this paper are plotted based on the original data. We think it should be more appropriate to plot the original data as the figures or tables for easier reading.

Besides, if the chloride content could be controlled within a reasonable range, the sea sand can still be used for concrete manufacture, such as the case of using desalinated sea sand. It is possible that chloride contained in sea sand may induce the steel corrosion after a period of casting. However, the corrosion propagation happens after corrosion initiation is significantly affected by the temperature and chloride concentration, which should be studied and is meaningful to properly predict the degradation process and service life of chloride contaminated constructions. Unfortunately, the related studies concerning the effects of temperature and chloride concentration on the corrosion behaviors of reinforcements were not thoroughly studied in the literatures. We believe that the results obtained in this study could provide some inspiring suggestions on investigating the effective service life of sea sand concrete constructed in some coastal areas, such as some coastal cities in China.

Author Response File: Author Response.pdf

Reviewer 2 Report

The well-written paper presents an experiment on finding the effects of temperature on the chloride-induced corrosion behavior of reinforcing steel. The methods and the conclusions are reasonable. Therefore, before recommendation for the final acceptance of this paper by this Reviewer, some minor revisions are suggested with details as follow:

1.- There's a possible drawback in the state of the art, because there's non references after 2015, it is suggested to include more updated references.

2.- Fig. 1. The figure it's not clear, define fig. (a) and fig. (b).

3.- Section 3.2. In the text separate clearly the description of fig. 5(a) and fig. 5(b).

4.- General point of view, it's a little hard to follow the reading in the description of figures (a or b), it is recommend to clearly specific each figure you’re describing in the text. A minor spell check is required.

Author Response

Respected Reviewers,

       We, the authors, have revised the manuscript in the light of your comments. We would like to thank you for your valuable suggestions and comments, which contributed to further elaboration of our manuscript. Please note that our responses (additions/modifications) are in bold words.

Regards,

The Authors

 

Reviewer 2:

The well-written paper presents an experiment on finding the effects of temperature on the chloride-induced corrosion behavior of reinforcing steel. The methods and the conclusions are reasonable. Therefore, before recommendation for the final acceptance of this paper by this Reviewer, some minor revisions are suggested with details as follow:

1.- There's a possible drawback in the state of the art, because there's non references after 2015, it is suggested to include more updated references.

Thanks for reviewer’s kind remind. The referenced published after 2015 have been updated in revised manuscript, including Refs. [4, 6, 7, 11, 17-22, 24, 28]. Please kindly see the details in newly submitted manuscript.

2.- Fig. 1. The figure it's not clear, define fig. (a) and fig. (b).

The definition of all figures throughout the paper, including Fig. 1, has been corrected in the revised manuscript.

3.- Section 3.2. In the text separate clearly the description of fig. 5(a) and fig. 5(b).

Thanks for reviewer’s remind. The descriptions of Fig. 5(a) and Fig. 5(b), referred as Fig. 6(a) and Fig. 6(b) in revised paper, have been corrected. Please kindly see Section 3.2 in the revised manuscript.

4.- General point of view, it's a little hard to follow the reading in the description of figures (a or b), it is recommend to clearly specific each figure you’re describing in the text. A minor spell check is required.

Thanks for reviewer’s valuable comments. The descriptions of all figures have been carefully checked before this submission. Efforts of improving English expression have also been made throughout the paper. The revised manuscript should be much better than the previous version.

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper deals with the effect of temperature on the corrosion in solution controlled at alkali environment. In the introduction, the effect of temperature on the corrosion of steel in concrete is introduced, however the paper only deals with the testing in solution. The corrosion processes in concrete is largely affected by oxygen-diffusion controlled phenomena and resistivity of cove concrete associated with moisture content as pointed out by the author. Those parameters should be studied when the effect of temperature on the corrosion in concrete is examined. Corrosion current density estimated by the linear polarization technique also has a limitation taking into consideration of the effect of capacitance.  

Author Response

Respected Reviewers,

       We, the authors, have revised the manuscript in the light of your comments. We would like to thank you for your valuable suggestions and comments, which contributed to further elaboration of our manuscript. Please note that our responses (additions/modifications) are in bold words.

Regards,

The Authors

 

This paper deals with the effect of temperature on the corrosion in solution controlled at alkali environment. In the introduction, the effect of temperature on the corrosion of steel in concrete is introduced, however the paper only deals with the testing in solution. The corrosion processes in concrete is largely affected by oxygen-diffusion controlled phenomena and resistivity of cove concrete associated with moisture content as pointed out by the author. Those parameters should be studied when the effect of temperature on the corrosion in concrete is examined. Corrosion current density estimated by the linear polarization technique also has a limitation taking into consideration of the effect of capacitance.

Thanks for reviewer’s significant comments. Due to the difficulty in squeezing out pore solution from concrete pore, the method of using simulated pore solution to study the corrosion mechanism of steel reinforcements inside the concrete is commonly adopted by many researchers, such as studies from Refs. [17, 23-28] in revised manuscript. It is true that this method has some expected shortages, such as without the consideration of oxygen-diffusion and moisture content as reviewer suggested, but the results obtained by this method could still be used as an indication for understanding the corrosion mechanism of steel rebars. Besides, the results presented in this paper are part of our research about the degradation mechanism of sea sand concrete structures. A series studies of the corrosion characteristics of steel reinforcements in real sea sand concrete is being carried out by our authors. We do hope our following study could be published in soon future.

Author Response File: Author Response.pdf

Reviewer 4 Report

Justification of findings and in depth explanations and novelty of this research has to be presented. The followings are my comments:

 

1) what is the literature gap and new in this study? There are number of studies conducted in the similar topic in the last 15 years or so. Please mention it in the abstract.

2) I am not quite sure how there is no initiation and direct propagation as you need to initiate something to propagate. Please elaborate the model and its concept behind? Cracking need to be initiated first and then it propagates?

3) How solution is the representative to the concrete or sand? Both are different media with different pore sizes, particle sizes and permeability.

4) With increasing temperature, the corrosion potential are decreasing right from the beginning? Why? Please explain in depth.

5) Do the time duration, justify the findings of this research? Explain how very small duration of few minutes can establish results?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 5 Report

1. The “with sea-sand” in the title is redundant. The sea sand is the motivation for the investigation, but not the investigated topic.
2. The introduction has many English mistakes. English editing is necessary for the introduction. The other sections are written with good English.
3. Reference number to Tuuti model is missing.
4. Pore solution is not a saturated limestone. It is acceptable as simulated pore solution. But should be discussed in the introduction.
5. The first sentence in the experimental program, shouldn’t it be “ribbed steel bar” instead of “twisted reinforcing steel”?
6. An example LP graph with its analysis will be helpful in the experimental section.
7. From the experimental section, I can infer that there was only one measurement per temperature and chloride concentration combination.
8. Figures 5, 6, and 8 and their corresponding tables 2, 3, and 4 – the value of R² is meaningless for this work. You could use p-value. What is more important but missing is the confidence interval for the slopes (and intercept). This confidence interval with the corresponding slopes should be used in statistical test to decide whether it is one slope for all the chloride concentrations or temperatures. If it is the same slope, the slope should be calculated from all the data to receive better accuracy. This is extremely important, because fixed slope is a fixed E_a, that means the chloride is not a catalyst (in contrast to what is written in the discussion), because catalyst reduces E_a. Hence, the chloride only changes the resistance of the passive layer.
9. In the conclusion, as long as you do not report the confidence interval, you cannot conclude reduction of E_a with concentration.
10. Since the simulated pore solution is far from real pore solution, a disclaimer should be entered in the conclusion.

Summery

The introduction needs English editing. A wider literature review is expected.

Statistics should be applied to the results

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

this article treat the effect of temperature in corrosion process, I don't find any changes in the article according to my recommandations,

however, I resend you the manuscrit in the PDF form with comments,.

Comments for author File: Comments.pdf

Author Response

Respected Reviewers,

       We, the authors, have revised the manuscript in the light of your comments. We would like to thank you for your valuable suggestions and comments, which contributed to further elaboration of our manuscript.

Regards,

The Authors

Reviewer 1:

This article treat the effect of temperature in corrosion process, I don't find any changes in the article according to my recommandations,

however, I resend you the manuscript in the PDF form with comments.

Q1: Authors can replace with “by using”.

A: The title has been modified as “Effects of temperature on corrosion behavior of reinforcements in simulated concrete pore solution by using sea-sand” in revised manuscript.

Q2: Authors may add as key word: sea sand.

A: Thanks for reviewer’s suggestion. The new key word “sea-sand” has been added in the revised paper.

Q3: Authors may complete references.

A: The cited reference of Tuutti’s model has been added in Line 29 of revised manuscript.

Q4: Authors may specify a) and b) in fig.1.

A: The (a) and (b) have been specified in Fig. 1 in Line 34-36 of revised paper.

Q5: Authors may change this figure (Fig. 2) by drawing a bar with high adhesion (the hatching of the bar).

A: The Fig. 2 has been modified according reviewer’s comment in Lines 78-79 of revised manuscript.

Reviewer 4 Report

I am still not convinced about the novelty of the research with 48 hours of testing. Similar research people have done for the duration of 7 days. I suggest authors to justify in the text about the novelty of the current research.  Go through more literature and present the novelty in the revised manuscript. 

Author Response

Q1: I am still not convinced about the novelty of the research with 48 hours of testing. Similar research people have done for the duration of 7 days.

A1: The following explanation has been added to the revised manuscript in Lines 111-118 of revised manuscript.

The purpose of conducting the electrochemical measurements after period of immersion is to obtain a reliable result without other interferences [30-32]. Basically, the measurements should be applied until the OCP values were stabilized enough, e.g., less than 2 [33] or 5 mV [34] within 5 min. In our study, the records of corrosion potential and corrosion current density were performed after 48 hours’ immersion. It was found the variations of OCP values were within 3 mV from 24 to 48 h, which is quite stable in our view and the same as the procedure adopted by Lu et al. [35]. Therefore, the results after 48 hours’ immersion presented in this study should be reliable and convincing.

[30] Y. Zhao, T. Pan, X. Yu, et al., Corrosion inhibition efficiency of triethanolammonium dodecylbenzene sulfonate on Q235 carbon steel in simulated concrete pore solution, Corros. Sci., 158 (2019) 108097.

[31] F. Zhi, L. Jiang, M. Jin, et al., Inhibition effect and mechanism of polyacrylamide for steel corrosion in simulated concrete pore solution, Constr. Build. Mater., 259 (2020) 120425.

[32] J. Qiu, Y. Li, Y. Xu, et al., Effect of temperature on corrosion of carbon steel in simulated concrete pore solution under anoxic conditions, Corros. Sci., 175 (2020) 108886.

[33] H. Yang, W. Li, X. Liu, et al., Preparation of corrosion inhibitor loaded zeolites and corrosion resistance of carbon steel in simulated concrete pore solution, Constr. Build. Mater., 225 (2019) 90-98.

[34] H. Zhang, Z.C. Yan, K.C. Shen, et al., Potentiodynamic and potentiostatic investigation on the passivation of Fe based glassy alloys in alkaline solution, J. Alloy. Compd., 857 (2021) 157573.

[35] P. Lu, B. Kursten, D.D. Macdonald, Deconvolution of the Partial Anodic and Cathodic Processes during the Corrosion of Carbon Steel in Concrete Pore Solution under Simulated Anoxic Conditions, Electrochimica Acta, 143 (2014) 312-323.

Q2: I suggest authors to justify in the text about the novelty of the current research.  Go through more literature and present the novelty in the revised manuscript. 

A：The following explanation has been added to the revised manuscript in Lines 47-55 of revised manuscript.

In addition, the individual effect of chloride concentration on the corrosion behavior were thoroughly studied by other researchers [17-22]. However, for the concrete structures made with sea-sand, there is no initiation stage of corrosion if the chloride content was exceeded the threshold value. Both chloride contents and temperatures should be the key parameters to predict the degradation process of sea-sand concrete during its service life. Nevertheless, the chloride concentration is rarely studied together with temperature as a combined influencing factor, which is more important for the sea-sand concrete structure considering its widespread utilization for building construction in some coastal areas, such as constructions in south of China.

[17] J. Shi, W. Sun, J. Jiang, et al., Influence of chloride concentration and pre-passivation on the pitting corrosion resistance of low-alloy reinforcing steel in simulated concrete pore solution, Constr. Build. Mater., 111 (2016) 805-813.

[18] S. Zhang, L. Hou, H. Du, et al., A study on the interaction between chloride ions and CO2 towards carbon steel corrosion, Corros. Sci., 167 (2020) 108531.

[19] S.H. Jin, H.J. Yang, J.P. Hwang, et al., Corrosion behaviour of steel in CAC-mixed concrete containing different concentrations of chloride, Constr. Build. Mater., 110 (2016) 227-234.

[20] W. Feng, A. Tarakbay, S. Ali Memon, et al., Methods of accelerating chloride-induced corrosion in steel-reinforced concrete: A comparative review, Constr. Build. Mater., 289 (2021) 123165.

[21] W. Tahri, X. Hu, C. Shi, et al., Review on corrosion of steel reinforcement in alkali-activated concretes in chloride-containing environments, Constr. Build. Mater., 293 (2021) 123484.

[22] L. Yan, G.L. Song, Z. Wang, et al., Crevice corrosion of steel rebar in chloride-contaminated concrete, Constr. Build. Mater., 296 (2021) 123587.