Effect of Combination of Expansive Agent and Fiber on Freeze-Thaw Resistance of High-Strength Concrete at Dry Environment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Topic is addressed for many years ago, testing differents elements like fiber to improve durability properties of concrete. Document contains valious data relative to use fiber and an expansive agent to increase concrete resistance freeze-thaw cycles. Approach research is adequaty, including a good experimental sequency to confirm the effectivity of mixes of substances to improve freeze-thaw performance of concrete samples. I consider that paper may be improved including recent references.

Comments for author File: Comments.pdf

Author Response

Thank you very much for taking the time to review this manuscript.

Thank you for pointing this out. I agree with this comment. Therefore, I have supplemented the literature in the introduction section of the article by adding recent references to research in the field and briefly describing the results of existing research.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

- I suggest you to put the mechanical characteristics of materials in table to be followed more easy (page 2);

- specify the number of samples that were tested;

- on the page 4 you said that "This suggests that dry environments have a negative impact on the development of HSC strength" but if you look at the graphs in figure 1 for samples HSC-5 and HSC-6 the statement is not true.

-   in the conclusion it is good to specify what are the practical aplications of this study, i.e. for which types of structural elements the "combination of expanding agent and fibre" is recomended and what are the costs per cubic meter of concrete.

Comments on the Quality of English Language

- Try to avoid formulas like "we measure" "we determine" see page 3;

Author Response

Thank you very much for taking the time to review this manuscript. my response to reviewer's comments are as follows:

Comments 1: I suggest you to put the mechanical characteristics of materials in table to be followed more easy (page 2); 

Response 1: Agree. I have put the mechanical characteristics of cement and AEA

Expansive Agent in Table 1.

Comments 2:specify the number of samples that were tested;

Response 2: Thank you for pointing this out. I agree with this comment. Therefore, I have specified the number of samples that were tested.This change can be found- page number 3, paragraph 1.

Comments 3:on the page 4 you said that "This suggests that dry environments have a negative impact on the development of HSC strength" but if you look at the graphs in figure 1 for samples HSC-5 and HSC-6 the statement is not true.

Response 3:The strength of both HSC-5 and HSC-6 samples in Fig. 1 increased with the increase in relative humidity. The highest strength of the samples was observed at standard humidity (RH>95%), which indicates that dry environment is detrimental to the strength development of concrete. Therefore, the conclusion is correct.

Comments 4:in the conclusion it is good to specify what are the practical aplications of this study, i.e. for which types of structural elements the "combination of expanding agent and fibre" is recomended and what are the costs per cubic meter of concrete.

Response 4: Agree. I have added the practical aplications of this study in conclusion. Based on the experimental results of this study, the concrete with both AEA expanders and steel fibres had the best frost resistance under dry conditions. This provides a reliable concrete mix ratios scheme for concrete construction projects in the cold and arid climate of Northwest China.

Comments 5:Try to avoid formulas like "we measure" "we determine" see page 3;

Response 5:Agree. I have change this style of expression. This change can be found- page number 3, paragraph 3.

 

Reviewer 3 Report

Comments and Suggestions for Authors

This article is interesting and provides useful information on “Effect of combination of expansive agent and fiber on freeze-thaw resistance of high strength concrete at dry environment” Therefore, the paper and its results are interesting, and the paper is considerably well written, so that I consider that a good paper for a high level Journal (as Applied Sciences) can be obtained based on this first version, provided that some issues are corrected and improved according to the following indications.

The abstract is well structured and summarizes the paper, but some conclusion lack to support the qualitative results (even an additional highlight with numerical results would be interesting).

Write the heading 1 Introduction in the manuscript.

The introduction section is very short and with few references.

I do not consider correct to cite so much references together, as "[3-8]" and more especially "[9-15]". If the references present different aspects of the idea which is being referenced, then they should be differentiated in the document, and if on the contrary they are similar regarding the idea to be referenced, then 1 or 2 are enough. The state of the art can be improved with elements related to concrete and fibers such as the following related manuscript: “Mechanical and Environmental Assessment of Lathe Waste as an Addiction to Concrete Compared to the Use of Commercial Fibres” Materials, 16(17),5740. DOI: 10.3390/ma16175740

Test method is very short, it is important to explain it in more detail

Results section presents good graphical information, but in figures 2 and 4 the results are not clearly visible, remake them in another way for a better visualization.

In the conclusions do not number them.

Conclusions section needs a restructuration so that the information is transmitted to the reader in a clearer way with a clear result of the analysis of such previous information.

I suggest that conclusions to include some recommendations for specialists on the field, based on results of research.

Author Response

Thank you very much for taking the time to review this manuscript. My response to the reviewer’s comments are as follows：

Comments 1:Write the heading 1 Introduction in the manuscript.

Response 1: Agree. I have added the title of Introduction.

Comments 2:The introduction section is very short and with few references.

Response 2: Thank you for pointing this out. I have added the latest references in the field of study and enriched the introduction section.

Comments 3:Test method is very short, it is important to explain it in more detail.

Response 3: Agree. I have enrich the details of freeze-thaw test and the Equation of mass variation.  In the revised manuscript this change can be found – page number3, paragraph4.

Comments 4:Results section presents good graphical information, but in figures 2 and 4 the results are not clearly visible, remake them in another way for a better visualization.

Response 4:

Thank you for pointing this out. I've changed the colours of the data cables for different types of concrete to make them easier to identify.

Comments 5:In the conclusions do not number them. Conclusions section needs a restructuration so that the information is transmitted to the reader in a clearer way with a clear result of the analysis of such previous information. I suggest that conclusions to include some recommendations for specialists on the field, based on results of research.

Response 5: Agree.I have removed the numbering and restructured the conclusion section. The areas of application and research implications of this study have been added at the end.

 

Reviewer 4 Report

Comments and Suggestions for Authors

Dear author,

Your article is written at a sufficient scientific level; however, the formatting needs correction. Units of measurement need to be added in the table after the comma. Additionally, values need to be formatted correctly, please check MDPI guide.

Author Response

Thank you very much for taking the time to review this manuscript.

I have made changes in the revised manuscript in response to the experts' comments, as shown in the table 2 and table 3.

Reviewer 5 Report

Comments and Suggestions for Authors

 

The article presents an study on the effect of the expansive agent and fibers on the freeze-twaw resistance of HPC.  My comments on the article are quite general as I have no specific points of improvement for the article, but rather ones that would affect the concept of the research.

The general assessment is that the research is well conducted, the methodology is correctly stated and the results and conclusions justified with the procedure. However, the scope of the article is very limited and the breadth of the research is narrow.

 

The incorporation of the materials studied is limited to a selection of six types of concrete with fixed contents, without considering the potential impact of varying proportions of these elements. It would be advantageous for the study to consider a broader range of combinations, which would allow for a more comprehensive understanding of their influence on the outcome.

Moreover, regarding the study of the compressive strength, only 28-days values are presented. In my opinion, the comparison with the 180-day values is crucial for elucidating the variation in the behaviour of these mixtures. Furthermore, in light of this observation, the conclusions drawn regarding the effect on flexural strength appear to be somewhat constrained.

It is recommended that the format of the publication be revised, in terms of fonts, texts and paragraphs, due to some discrepancies.

The state of the art, which is quite small, could be expanded.

The article needs a major language revision. There are numerous errors in expression throughout the paper that are evident even to non-native speakers. English proofreading is essential for publication of the paper.

 

 

 

 

Comments on the Quality of English Language

·       The article needs a major language revision. There are numerous errors in expression throughout the paper that are evident even to non-native speakers. English proofreading is essential for publication of the paper.

Author Response

Thank you very much for taking the time to review this manuscript. My response to the reviewer’s comments are as follows：

Comments 1: The incorporation of the materials studied is limited to a selection of six types of concrete with fixed contents, without considering the potential impact of varying proportions of these elements. It would be advantageous for the study to consider a broader range of combinations, which would allow for a more comprehensive understanding of their influence on the outcome.

Response 1: I agree with this comment. This could be a direction for further research in the future.

Comments 2:Moreover, regarding the study of the compressive strength, only 28-days values are presented. In my opinion, the comparison with the 180-day values is crucial for elucidating the variation in the behaviour of these mixtures. Furthermore, in light of this observation, the conclusions drawn regarding the effect on flexural strength appear to be somewhat constrained.

Response 2: The variation patterns of compressive strength and flexural strength under different humidity conditions for 28d and 180d respectively are shown in Fig. 1 and it is found that both compressive strength and flexural strength increase with the increase in humidity. Therefore, this conclusion is reasonable.

Comments 3:The article needs a major language revision. There are numerous errors in expression throughout the paper that are evident even to non-native speakers. English proofreading is essential for publication of the paper.

Response 3: Agree. I have revised the language throughout the article. Please review it.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have taken into account all my suggestions, and the paper has improved considerably due to this changes as well as the ones suggested by the other reviewers. The explanation of the changes is also clear and rigurous.

Therefore, in my opinion the paper is now worthy of publication.