Study on the Basic Mechanical Properties and Discrete Element Method Simulation of Permeable Concrete

Round 1

Reviewer 1 Report

1.        The abstract is more a descriptive abstract instead of an informative abstract. Please make it more informative by replacing quantitative phrases with qualitative ones. 2.        The purpose of this investigation and innovation of this paper should be clearly pointed out and emphasized at the end of Introduction. 3.        Full names of a few abbreviations should be given when they appear for the first time.

4.        The format of the paper needs to be improved and there are some typos in some positions.

5.        The format of the table should be adjusted accurately according to the journal to avoid misunderstanding.

6.        The clarity of the figures needs to be improved, such as Figs. 4-1, 4-8, 4-12, 4-13, 4-16, 4-18, 5-1, 5-5, and 5-6.

 English needs polishing. Tense should be consistent. Missing punctuation should be added. Grammar errors should be eliminated.

Author Response

The authors would like to thank all editors and reviewers for the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated all of the suggestions made by the reviewers. Those changes are highlighted in the manuscript in red. The main corrections in the paper and the response to the reviewer’s comments are as flowing:

Response to Reviewer #1:

1. The abstract is more a descriptive abstract instead of an informative abstract. Please make it more informative by replacing quantitative phrases with qualitative ones.

More detailed content has been added to the summary section, and some of the contents have been modified, which have been marked in red in the article.

2. The purpose of this investigation and innovation of this paper should be clearly pointed out and emphasized at the end of Introduction.

The purpose and innovation of this study have been added at the end of the introduction.

3. Full names of a few abbreviations should be given when they appear for the first time.

The full acronym was given when it first appeared in the article and was marked in red in the article.

4. The format of the paper needs to be improved and there are some typos in some positions.

The format of the paper has been corrected in accordance with the requirements of the journal, and the grammatical errors in the article have been corrected.

5. The format of the table should be adjusted accurately according to the journal to avoid misunderstanding.

The format of the table has been corrected in accordance with the requirements of the journal.

6. The clarity of the figures needs to be improved, such as Figs. 4-1, 4-8, 4-12, 4-13, 4-16, 4-18, 5-1, 5-5, and 5-6.

Pictures 4-1, 4-8, 4-12, 4-13, 4-16, 4-18, 5-1, 5-5, and 5-6 have been replaced with clearer pictures.

Reviewer 2 Report

1. What is the main question addressed by the research?

Permeable concrete as a sustainable material is proposed. The new modeling methodology is proposed to predict the behavior of permeable concrete  and shown to be successful in predicting and validating some of the parameters.
2. Do you consider the topic original or relevant in the field? Does it
address a specific gap in the field? Yes, need for a new and improved modeling methodology is always there
3. What does it add to the subject area compared with other published
material? An effective modeling methodology is proposed compared to the ones already published
4. What specific improvements should the authors consider regarding the
methodology? What further controls should be considered? Author need to put their uniqueness of this research or novelty in the crisp and precise manner in the introduction part.
5. Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed? Yes, conclusions are fine and answer the questions
6. Are the references appropriate? Yes, references are appropriate  

line 19 explain 50% 5-15mm+50% 10-15mm????

Table 2.1   what is 3d and 28d

Fig 3.1...how many specimens were tested? standard deviation? scatter band?

line 504 spelling mistake

line 516 spelling mistake

Figure 4.18 and 4.19 plots ..image not clear...can't read numbers

Two plots not matching in shape, why?

 

Figure 5.6 title...a and c are same??? 

 

Article is useful but how it is unique?

Please justify the uniqueness of the research

 

Check english for spellings and grammer

 

Check grammer and spellings

Author Response

The authors would like to thank all editors and reviewers for the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated all of the suggestions made by the reviewers. Those changes are highlighted in the manuscript in red. The main corrections in the paper and the response to the reviewer’s comments are as flowing:

Response to Reviewer #2:

1. line 19 explain 50% 5-15mm+50% 10-15mm?

50% 5-15mm+50%10-15mm refers to the mixed aggregate size obtained by mixing 50% 5-15mm aggregate size with 50% 10-15mm aggregate particle size.

2. Table 2.1 what is 3d and 28d?

3d and 28d in Table 2-1 refer to three days and 28 days, respectively.

3. Fig 3.1...how many specimens were tested? standard deviation? scatter band?

Three samples were taken from each of the three kinds of aggregates for compression and permeability tests, and the test results were taken as the average value.Not tested standard deviation and scatter band.

4. line 504 spelling mistake.

The spelling error has been corrected.

5. line 516 spelling mistake.

The spelling error has been corrected.

6. Figure 4.18 and 4.19 plots ..image not clear...can't read numbers

Figure 4.18pr 4.19 has been replaced with clearer pictures.

7. Two plots not matching in shape, why?

An error occurred while drawing, which has now been corrected. The corrected picture is shown in figure 19.

8. Figure 5.6 title...a and c are same?

The title name was misspelled when describing the title, which has been corrected, as shown in figure 5.6.

9. Article is useful but how it is unique?

In this study, the binocular Blu-ray three-dimensional scanner is used to scan the aggregates one by one in order to establish a more realistic aggregate model, and explore the influence of the number of contacts on the mechanical properties of the numerical model, which has not been done by the predecessors. For details, see the red section of the introduction.

1. 10. Check english for spellings and grammer.
   11. Spelling and grammar errors have been corrected.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript delves into the Study of basic Mechanical Properties and Discrete Element Method Simulation of permeable concrete. Various tests, including mechanical properties, Particle flow; Discrete element method(DEM), and Numerical simulation, have been conducted. The document provides a comprehensive exploration of the mechanical properties of concrete and the influence of Discrete Element Method Simulation. The inclusion of mathematical models, graphs, and tables adds depth to the research. However, the manuscript would benefit from further clarity, organization, and detailed explanations in certain sections.

 

Comments for Improvement:

1. Introduction: A well-structured introduction setting the context and significance of the study is essential. If not present, consider adding it.

The investigation's description is vague and should be clarified with additional details. Add a concluding statement that emphasizes the significance and potential of this research.

The abstract should explicitly describe the novelty of the proposed method and the article's added value. Highlight the novelty of the research at the end of the introduction section, and also make the table of contributions of this work

2. Figures & Tables: Ensure all figures and tables (e.g., Fig 4-2, Fig 4-8, Fig 4-12, Fig 4-13, Fig 4-18, Fig 5-1, Fig 5-5, Fig 5-6,) are clearly labeled, have descriptive captions, and are referenced appropriately in the text. Please add high-quality figures.
3. Discrete element method (DEM), Numerical simulation: The DEM and Numerical simulation sections could benefit from more detailed explanations. For instance, how do the results from these analyses correlate with the observed mechanical properties?

I strongly recommend comparatively analyzing your work with previous researchers, to justify the accuracy of your results. The current study is lack this point.

4. Results Interpretation: In the section discussing the relationship between compressive strength and 3.            Discrete element method (DEM), Numerical simulation, consider elaborating on the significance of the correlation coefficient and how it impacts the study's conclusions.
5. Literature Citations: Ensure all referenced literature, such as the "Code for Design of Concrete Structures," is appropriately cited, and a comprehensive bibliography is included.

The literature section is lacking in discussing the design and performance of concrete composite mix design. https://doi.org/10.3390/ma15207346, https://doi.org/10.3390/ma16010261, Please add more literature to this.

6. Conclusion: A well-summarized conclusion highlighting the key findings, their implications, and potential future research directions would be beneficial. The conclusion should be more carefully rewritten, summarizing what has been learned and why it is exciting and valuable.
7. Language & Grammar: The authors should check typing errors throughout the manuscript. English style should also be improved.

The acronyms have been defined in multiple locations. Please avoid repetitions.

8. Comparative Analysis: If possible, compare the properties of concrete with previous researcher work to provide readers with a frame of reference.
9. Practical Applications: Elaborate on the real-world applications of permeable concrete and its advantages and disadvantages compared to other methods.
10. Limitations: Every study has limitations. Clearly outline the limitations of your research and methodologies.

11.  Recommendations: Based on the findings, provide recommendations for construction professionals or policymakers regarding the use of coral concrete. Add the policy recommendation of the study for future aspects.

 

Final Comments

Major Revision

 Moderate editing of English language required

Author Response

The authors would like to thank all editors and reviewers for the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated all of the suggestions made by the reviewers. Those changes are highlighted in the manuscript in red. The main corrections in the paper and the response to the reviewer’s comments are as flowing:

Response to Reviewer #3:

1. Introduction: A well-structured introduction setting the context and significance of the study is essential. If not present, consider adding it.The investigation's description is vague and should be clarified with additional details. Add a concluding statement that emphasizes the significance and potential of this research.The abstract should explicitly describe the novelty of the proposed method and the article's added value. Highlight the novelty of the research at the end of the introduction section, and also make the table of contributions of this work。

The background and significance of the research have been added to the introduction. The significance of this study is that the numerical simulation is carried out by using PFC3D software, and the simulation results are compared with the experimental results, the error is only 3%, which proves the reliability of the simulation results. The use of numerical simulation method in this study can greatly reduce the workload of the laboratory. The novelty of this study is to use a binocular Blu-ray three-dimensional scanner to scan aggregates one by one in order to establish a more realistic aggregate model and ensure the reliability of the simulation results. In this paper, this part is added in the abstract and introduction, and this part has been marked red in the article.

2. Ensure all figures and tables (e.g., Fig 4-2, Fig 4-8, Fig 4-12, Fig 4-13, Fig 4-18, Fig 5-1, Fig 5-5, Fig 5-6,) are clearly labeled, have descriptive captions, and are referenced appropriately in the text. Please add high-quality figures.

Figures 4-2, 4-14, 4-13 add more detailed descriptive titles, and figures 4-8, 4-18, 5-1,-5-5, 5-6 have been replaced with clearer pictures.

3. Discrete element method (DEM), Numerical simulation: The DEM and Numerical simulation sections could benefit from more detailed explanations. For instance, how do the results from these analyses correlate with the observed mechanical properties?I strongly recommend comparatively analyzing your work with previous researchers, to justify the accuracy of your results. The current study is lack this point.

The results of numerical simulation analysis are compared with the experimental results, and the error is only 3%. This content is mentioned in 4.2.3 and 5.1.1. The reliability of the simulation is proved by the experimental results. Compared with the previous research work, this study uses PFC3D to simulate the compressive performance of permeable concrete, which is more clear and beautiful visually, and the accuracy of numerical simulation results is higher, and it is proved that the mechanical properties are closely related to the number of contacts between the simulation model particles.This paper adds a comparison with previous studies in 5.2.1, as shown in Table 5-2.

4. Results Interpretation: In the section discussing the relationship between compressive strength and 3. Discrete element method (DEM), Numerical simulation, consider elaborating on the significance of the correlation coefficient and how it impacts the study's conclusions.

In this paper, the relationship between compressive strength test and numerical simulation is explained in 4.2.3. In 5.2.1, the meanings represented by the number of aggregate particles, the number of original particles, the relative density, the number of linear parallel bond contact and the contact number of horizontal joints are explained in the numerical simulation. The supplementary content has been marked red in the article.

5. Literature Citations: Ensure all referenced literature, such as the "Code for Design of Concrete Structures," is appropriately cited, and a comprehensive bibliography is included.The literature section is lacking in discussing the design and performance of concrete composite mix design.https://doi.org/10.3390/ma15207346,https://doi.org/10.3390/ma16010261, Please add more literature to this.

In this paper, the reference to the specification of experimental method is supplemented in 2.4 and 3.1.1. In the literature part, the discussion on the design and performance of concrete composite mixture is added. The additions have been marked red in the article.

6. Conclusion: A well-summarized conclusion highlighting the key findings, their implications, and potential future research directions would be beneficial. The conclusion should be more carefully rewritten, summarizing what has been learned and why it is exciting and valuable.

This paper revises the conclusion to highlight the impact of this study and the potential research direction in the future. The maximum error between the numerical simulation results and the experimental results of the discrete element model of permeable concrete established by the modeling method in this paper is about 3%. This proves that the numerical simulation method used in this study can effectively guide the mix design and preparation process of permeable concrete, and provides convenience for the follow-up research of permeable concrete. In the follow-up study, the discrete element method and hydrodynamics method can be combined to simulate the permeability of permeable concrete in order to comprehensively consider the mechanical properties and permeability of permeable concrete by numerical simulation method.

7. Language & Grammar: The authors should check typing errors throughout the manuscript. English style should also be improved.The acronyms have been defined in multiple locations. Please avoid repetitions.

Grammar and spelling problems have been corrected, and acronyms have been avoided to be defined repeatedly in multiple locations.

8. Comparative Analysis: If possible, compare the properties of concrete with previous researcher work to provide readers with a frame of reference.

This paper gives a supplementary description of the comparison with previous research work in 5.2.1, as shown in Table 5-2.

9. Practical Applications: Elaborate on the real-world applications of permeable concrete and its advantages and disadvantages compared to other methods.

The research method of this paper is limited by the computational efficiency, and the cement paste is not represented by the discrete element modeling, and its function is realized by setting a reasonable contact model. However, this method has high accuracy and small error, which provides convenience for the follow-up research of permeable concrete.This problem is explained in detail in 5.2.1 and 6.

10. Limitations: Every study has limitations. Clearly outline the limitations of your research and methodologies.

In this study, the fluidity of the paste is not considered in the mix design, which leads to the blockage of pores and the decrease of water permeability of cement paste. And the water permeability is not simulated. This problem is discussed in detail in the conclusion.

11. Recommendations: Based on the findings, provide recommendations for construction professionals or policymakers regarding the use of coral concrete. Add the policy recommendation of the study for future aspects.

This problem has been explained in detail in the conclusion of this paper.In the follow-up study on the influence of paste-to-bone ratio on the performance of permeable concrete, we can take the maximum thickness of aggregate as a reference factor, reasonably control the paste-to-bone ratio, and comprehensively consider the calculation efficiency and model accuracy, and bring the cement paste into the category of modeling. The discrete element method and hydrodynamics method can also be combined to simulate the permeability of permeable concrete in order to comprehensively consider the mechanical properties and permeability of permeable concrete by numerical simulation method.

Reviewer 4 Report

The paper "Study on basic Mechanical Properties and Discrete Element Method Simulation of permeable concrete"  used the single factor test method to analyze how aggregate size, slurry-to-bone ratio, and loose paving coefficient affect permeable concrete's mechanical properties and permeability. Some suggestions are presented below:

 

The article is dense, with a high content of figures and sections. The article could become more fluid if some figures were combined within the text.

There are many typing errors, with various punctuation marks in the middle of sentences, for example, on lines 99, 441, 445, 455, 491, 516, among others. Please review.

Why is there the same sentence in the lines 389 and 499?

What is presented in Figure 19?  The graph is not in English.

The conclusion 2 was not clear. 

I would like to see more discussions about the application of the model to permeable concrete. What is the conclusion drawn from applying the model in the study?

Author Response

The authors would like to thank all editors and reviewers for the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated all of the suggestions made by the reviewers. Those changes are highlighted in the manuscript in red. The main corrections in the paper and the response to the reviewer’s comments are as flowing:

Response to Reviewer #4:

1. The article is dense, with a high content of figures and sections. The article could become more fluid if some figures were combined within the text.

Table 5-1 is modified in the text to explain the data in more detail.

2. There are many typing errors, with various punctuation marks in the middle of sentences, for example, on lines 99, 441, 445, 455, 491, 516, among others. Please review.

Spelling errors and punctuation errors have been corrected.

3. Why is there the same sentence in the lines 389 and 499?

The same sentence has been revised in the text.

4. What is presented in Figure 19?  The graph is not in English.

The reliability of the parameter calibration of the discrete element model is proved by comparing the compressive strength test results of fig. 19 with the compressive strength results of numerical simulation. The content of the picture has been revised to English.

5. The conclusion 2 was not clear. 

The conclusion has been revised. See the red section of the conclusion

6. I would like to see more discussions about the application of the model to permeable concrete. What is the conclusion drawn from applying the model in the study?

The meso-model of permeable concrete is established by using the discrete element numerical simulation method, and compared with the macroscopic test results in the laboratory, the dependence on the actual test work can be minimized.In addition, the simulation test using the three-dimensional numerical model of permeable concrete particle flow can more truly reflect the structural characteristics, deformation characteristics and failure mechanism of permeable concrete, and broaden the application range of permeable concrete.This paper gives a supplementary explanation to this problem in the introduction and conclusion.

Finally, thank you again for your guidance, and thank you for reviewing and revising my revised paper again.

 

Round 2

Reviewer 2 Report

looks ok now

Reviewer 3 Report

no comments