Efficiency of Waste as Cement Replacement in Foamed Concrete—A Review

Round 1

Reviewer 1 Report

Dear authors,

I have following suggestion to improve this work further:

1. The introduction is adequate, but could be improved. The gaps in the state of research at the moment are not entirely clear. The authors should make an attempt to address it near the end of the introduction.

2. The authors should refer a bit more in the introduction and the manuscript. The current references can be enhanced, with emphasis on recent research from last 3 to 5 years.

3. The conclusion section should conclude the research properly. Right now, it is too short to be considered as a conclusion. Even it is shorter than the abstract, which is highly unusual. Authors should make an effort to improve the conclusion in a very well manner. There is a need to present the conclusions and implications of the study in a much better way. It should be discussed very clearly how the current research enriches literature and contributes to practice.

Author Response

Dear Editor and Reviewers,

We are very much thankful to the reviewers for their invaluable comments and critical evaluation of the manuscript which helped us to improve its quality substantially. The suggestions and comments were quite helpful for us and we incorporate each of them into the revised paper and responses letter as attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

The article is devoted to the topical topic of using various kinds of waste as a binder for cement production. Unfortunately, the review is a listing of the results obtained by other authors without analyzing the totality of these results. This is largely confirmed by the presence of figures and tables borrowed from other authors. In this form, a review article is not suitable for its evaluation from the point of view of scientific contribution.

Author Response

Comments: the review is a listing of the results obtained by other authors without analyzing the totality of these results.

Responses: Thank you reviewers’ comments. The results obtained has further analyzed and improved in manuscript.

Comments: This is largely confirmed by the presence of figures and tables borrowed from other authors.

Responses: the figures and tables has been improved accordingly. 

Reviewer 3 Report

1) Why do the authors refer only to the ASTM C618-19 standard when classifying ash? There are a lot of European standards that also talk about other classes and the use of ashes in materials with a cement binder.

2)The inserted morphological photos of the materials (SEM) are of very poor quality. Please post better-quality photos. Also, not all of them have a scale (Figure 3).

3)Photos 7-9 should be replaced with better quality, data cannot be read from them.

4)If a trend line is drawn, its equation and the determination of the R2 coefficient should also be included

5)Measurement errors should be taken into account, as the values quoted in the charts overlap in some points.

6) The conclusions should also be extended, the authors, when conducting a scientific review, should make several important conclusions for others, and above all, make the purpose of their publication visible.

7)  The author did not perform a statistical analysis of the measurement error. I don't know why? The graphs do not include the uncertainty of the result and the methodology does not describe how the uncertainty was calculated and what coefficients were selected for this. Please comment on this and make corrections

8)On the basis of so many research results, could it be tempted to determine the correlation coefficients for the decrease or increase in concrete strength, change in the rheology of the mixture or other parameters?

9) Abstract needs to modify: the abstract should contain Objectives, Methods/Analysis, Findings, and Novelty /Improvement.
10) More explanation is needed for where there is a research gap and what the goals of the research are. The research gap and the goals of the research are not explained in detail which leads to the reader missing the significance of the research.
11) However, in its present form, the manuscript contains several weaknesses. Appropriate revisions to the following points should be undertaken in order to justify the recommendation for publication.
12) Please add a sentence or two to clearly recap how your study differs from what has already been done in the literature to ascertain the contributions more strongly.
13) For readers to quickly catch your contribution, it would be better to highlight major difficulties and challenges, and your original achievements to overcome them, in a clearer way in the abstract and introduction.
14) Some key parameters are not mentioned. The rationale for the choice of the particular set of parameters should be explained in more detail. Have the authors experimented with other groups of values? What are the sensitivities of these parameters on the results? 
15) Some assumptions are stated in various sections. Justifications should be provided for these assumptions. Evaluation of how they will affect the results should be made.
16) This raises some concerns regarding the potential overlap with the authors' previous works. The authors should explicitly state the novel contribution of this work, and the similarities and differences between this work with their previous publications.

Author Response

Dear Editor and Reviewers,

We are very much thankful to the reviewers for their invaluable comments and critical evaluation of the manuscript which helped us to improve its quality substantially. The suggestions and comments were quite helpful for us and we incorporate each of them into the revised paper and responses letter as attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have revised the article, improved the text. However, I am of the opinion that even in the review to give verbatim 7 figures from the research of third-party authors, even with a link. After all, this is not didactic material and not a textbook. Still, in my opinion, you should either make your own graphic abstraction of the process or remove figures from the text.

Author Response

Dear Editor and Reviewers,

We are very much thankful to the reviewers for their valuable comments and critical evaluation of the manuscript which helped us to improve its quality substantially. The suggestions and comments were quite helpful for us and we incorporate each of them into the revised paper and responses letter as attached.

Author Response File: Author Response.pdf

Reviewer 3 Report

Thank you very much for the revised text and direct reference to my comments. Currently, the text is very good and meets the requirements of the journal. Therefore, I also do not accept all the comments made and direct the manuscript to print. Once again, thank you very much to the authors for the corrections and congratulations on a great job!!!

Author Response

Reviewer comments: the text is very good and meets the requirements of the journal.

Author responses: Thank you very much.

Round 3

Reviewer 2 Report

My opinion hasn't changed. There is a lot of material used in the form of drawings used in the text. The contribution of the authors is not clear.