Impact of Water Level Variation on Mechanical Properties of Porous Concrete

Round 1

Reviewer 1 Report

In this article, the author selected Type I (Grade 43) ordinary Portland cement (OPC) to explore the effects of porous concrete, groundwater level changes, and porosity on the mechanical, physical, and hydraulic properties of porous concrete. Through experiments, it has been found that the compressive strength of porous concrete varies significantly under different water level conditions, which can prevent unnecessary flash floods and protect natural water circulation in the future. In addition, construction and demolition related waste can be recycled as building materials, which can not only suppress pollution but also reduce dependence on limited resources. There are the following errors that need to be corrected.

1. The logic of the introduction writing is not very smooth. For example, the author's explanation of the advantages and disadvantages of PC is not clear enough.

2. Inconsistent titles, numerical descriptions, and table formatting issues. For example, the table format on pages 6 and 7.

3. Uneven punctuation at point 2 on page 1.

4. The format on page 11 is chaotic, with different font positions.

5. The size of the image on page 14 varies.

6. The compressive strength needs to be further verified by other experiments.

7. Will the drying factors in the oven during the experiment make the results less referenceable?

8. There are some newly published relevant literatures can refer to, just as below:

[1] Construction and application of fuzzy comprehensive evaluation model for rockburst based on microseismic monitoring. Applied Science. 2023, 13(21): 12013. https://doi.org/10.3390/app132112013

[2] Research on the technology of gob-side entry retaining by pouring support beside the roadway in three soft coal seam A case study. Physics of Fluids. 2024, 36(1): 017123. https://doi.org/10.1063/5.0186678

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper investigates the porous concrete and the impact of water variations and porosity on the mechanical, physical, and hydraulic properties. The effect of different void percentages and various water levels on the properties of the porous concrete is studied. The permeability of the specimens is assessed using a falling head permeameter to ensure effective water percolation. Porosity is quantified through a volumetric method, providing insights into void content. Although the topic is very interesting, but the manuscript is very poorly written and presented. Applying the following comments and suggestions will improve the current version of the manuscript.

·       It is recommended to rewrite the abstract. In its current form, the abstract lacks clarity, making it difficult to emphasize crucial information.

·       The introduction section lacks a comprehensive critical review of previous studies. The current presentation of the literature review is notably limited and should be expanded to incorporate more recent studies. Additionally, it is advisable to avoid the compounding of references.

·       Most importantly, the introduction section does not provide any details on the issues with hydroplaning surfaces.

·       As per the existing technical literature related to this paper, the innovation in the article should be elucidated in contrast to other research endeavors.

·       At the end of introduction, add a brief para describing the paper organization.

·       The referencing style utilized in the introduction section deviates from mdpi standard conventions. It is advisable to adopt a recognized referencing style.  

·       It is recommended to add a brief description of the guidelines set forth by ACI/ASTM codes for material preparation.

·       What was reason behind selecting the targeted porosities of 20% and 25%?

·       How accurate was the assumption used in calculating the minimum volume of paste required?

·       Any specific reason for selecting "24" specimen for each cubical and cylindrical shapes?

·       For wet conditions, the authors did not take into the account the dynamics forces they may arise from the water sloshing, which in my opinion would affect the stability of the specimen. I would suggest the authors should look into this aspect also.

·       Figures 2 and 3 have the same caption. Correct it by specifying the type of specimen showing in each Fig.

·       Nearly all tables differ from the text in terms of font type and size. It is advised that font sizes and types in tables be standard and consistent.

·       What was the reliability/accuracy of the falling head permeameter used to measure coefficient of permeability?

·        Results lacks the quantitative discussion.

·       Conclusion should be more inclusive. Please work to improve it with details of results.

Moderate editing of English language required

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This research aims to study the effects of water level variation on the compressive strength of porous concrete using experimental methods. Additionally, porosity and permeability of the porous concrete are also measured to ensure the functionality of porous concrete.

However, from a scientific point of view, the study could be useful for knowledge in the field.

My comments and recommendations are the following:

At line 166, at section “Material”, it may be useful to introduce the standards/norms in the field.

At line 162 - it may be useful to introduce the standard.

Line 173 – “The common physical properties” . The study refers to an original experimentation. It must to specify the properties of the materials under study, not common.

Line 175 – The abbreviations AIV, ACV, etc. are not detailed in manuscript bodytext. They are define below.

Line 182 – Why the target for porosities is of 20% and 25%? Please define the conditions

Line 184 - What represents very high porosities? It could be true if the reference values are specified.

Line 185 – “ … of twenty and twenty-five …” - of twenty and twenty-five PERCENT”

Line 186 – “Table … Design Properties”. The values are not proper specified. 20.000? 12.000? etc.

Line 207- The presented parameters for the analyzed two types, are the same. It can be removed this table and included a paragraph.

Line 348- “ in the porous specimens unveiled disparities …” – “in the porous specimens unveiled differences “

Line 349 – “Significantly,” is not proper used.

Line 350 – “anticipated porosity “ – “estimated porosity”

Figure 12 and Figure 13 they are wrong.  If it is compared with a reference value, then this must be indicated in the figure. The regression fit indicates the correlation of the analyzed data.

Line 409 – “showed significant change in compressive strength value.” What is the percent/value of significant difference? The comparative analyzes presented in the paper indicate something else.

In order to be accepted, I recommend that the article to be improved. Also, the tables are not numbered and formatted according to the template imposed by the journal.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Dear Authors, after reading your manuscript, I have the following comments:

1. Incorrectly formatted literature.

2. There is absolutely no Discussion section in the manuscript, so the Authors do not compare their results with others.

3. The manuscript lacks information about the contribution of each of the Authors.

4. The Authors sent their manuscript to the journal Sustainability, but it is not clear from the Introduction why this particular journal was chosen. In my opinion, this manuscript is better suited to the Buildings. If the Authors insist on this journal, then it is necessary to emphasize what ecological or economic effect can be obtained after conducting experimental studies.

5. The conclusion is very long. Compare the conclusion with the aim.

Also, note that the manuscript lacks scientific novelty. It should be! In this form, your manuscript looks like a report of completed engineering work.

6. In Figures 6 and 7, NUMERICAL VALUES SHOULD BE ROUNDED UP TO TWO VALUES AFTER THE COMMA. Also pay attention to the design of formulas.

7. In my opinion, it is necessary to justify why CEM-1 type cement was chosen for research. Due to the large amount of CO2 emissions into the atmospheric air in the world, there is a tendency to refuse even the production of such cement. It is replaced by CEM-4 or CEM-5

Best regards!

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report

Dear authors

The paper aimed to investigated the porous concrete and the impact of water table variations and porosity on the mechanical,  physical, and hydraulic properties of porous concrete. After reading the paper, some issues, i think, must be addressed and improved.

1) The presentation of the paper is so poor. Some error indicator was existed, such as in line 240. All tables and figures were not well organized and arranged. The references were also not correctely formated. Figrues were not right insertation into the texts.

2) Only 3 samples were tested? It is too less to get a accurate results. Just as the results you obtained, it is not correct that compressive strengths of air-dried samples were less than 40% level. Meanwhile, the results in the Fig. 6 and 7 should linearly decrease. Therefore, the conclusions you get is not correct.

3) From table 4, it seems that there were only two void percentages for cubic and cylinderic samples. It is reliable to evaluate the eefect of void percentage on the compressive strengths of samples.

4) For table 12 and 13, only two target porosity, why did you fit them?

5) Why did not you fit the water condition vs. strength? It is the main aim of this study.

6) The conclusions were too long to read. It is recommend that simplify them to concise ones. Do not repeat the results. Further conclude results into conclusions.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The manuscript has been significantly improved. I would like to recommended the manuscript for publication.

Reviewer 3 Report

The quality of this article has been improved. The paper may be accepted in present form.

Reviewer 5 Report

Dear authors

The paper has been improved. I think it can be accepted for publication.