Study on the Micro Mechanism of Failure Evolution of Desulfurization Gypsum–Fly Ash Fluidized Lightweight Soil Based on Discrete Element Method
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript entitled "Study on the Micro Mechanism of Failure Evolution of Desulfurization Gypsum-Fly Ash fluidized Lightweight Soil Based on Discrete Element Method" presents an analysis utilizing the discrete element method numerical simulation to investigate the mechanical behavior of desulfurization gypsum-fly ash fluidized lightweight soil under uniaxial compression testing. The research aims to elucidate the failure mechanism of the material, assess crack evolution in conjunction with energy variations, and explore particle motion characteristics during testing. A two-dimensional discrete element numerical model was established based on a specified gradation, followed by the determination of micromechanical parameters for the contact model. The study analyzed strain and stress from numerical simulations and indoor experiments, focusing on crack evolution and its impact on the fracture surface.
The literature review in the Introduction section is satisfactory. The discussion of the methodology is enough. The references are up-to-date. The experimental section presents the results satisfactorily. The authors also compared their results with state-of-the-art models, and the proposed method is shown to be useful.
The major concerns about the manuscript are its organization and missing statistical methods. The organization of the manuscript is a little confusing; materials, methods, results, and discussion are presented under the same section. A research paper should be organized as an Abstract, Keywords, Introduction, Materials and Methods, Results, Discussion, and Conclusions.
The second major concern is that no statistical procedure was applied for data analysis and comparison of the results. This is the major missing element in a research paper.
Following the general assessments mentioned earlier, you will find additional improvements listed below:
1. The technical term "Desulfurization gypsum-fly ash fluid lightweight soil" seems a bit strange to me, so I suggest the authors double-check it.
2. "Simple" should be changed to "Sample" in Table 1.
3. Line 133: Explain the abbreviations in the first use. Please check all.
4. The organization of the manuscript is a bit confusing. Material, Method, and Results are presented together under the same section. For example, Figure 3, including the results, should be presented in the section of Results, but it is presented in the section of "Test materials and test plans," and there is no section of Results. I suggest the authors organize the manuscript into the sections of Abstract, Keywords, Introduction, Materials and Methods, Results, Discussion, and Conclusions.
5. Number of some sections are wrong and should be corrected. 1.2, 1.3 and 1.4 should be changed to 2.2, 2.3 and 2.4 respectively.
6. "2. Discrete Element Model and Parameter Inversion" should be changed to "3. Discrete Element Model and Parameter Inversion." All the numbers of the subheadings under this section are wrong and should be corrected.
7. Results should be compared with previous papers for deeper discussions.
Comments on the Quality of English Languageminor revision
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have modelled the micro-mechanisms underlying the failure evolution of desulphurisation gypsum-fly ash fluidised lightweight soil, using the discrete element method for analysis. The paper is well written and of interest to readers of coatings. The results are explained, but perhaps more references should be included to consolidate the findings.
Most importantly, the paper does not follow an academic paper structure by mixing the different parts (experimental-results-discussion). Therefore, authors should separate the article into two parts (experimental-results/discussion) if they wish, to make it easier to read.
If the article is adapted to an academic structure, it seems to me to be a good candidate for publication in Coatings, but in this form it would not be ready for acceptance.
Authors should clearly separate the experimental part from the results and discussion. For example, section 1.4. Stress-strain curve, has a first paragraph clearly stating how it was done, then the authors describe the results obtained in Figure 3 and give an explanation. This last part should be separated and placed in a results section. In this way, the structure would be Introduction, Experimental, Results and Discussion and Conclusions. The same procedure should be followed for section 2.2. Microscopic model parameter calibration.. Another clear example is Section 3.2. Analysis of Energy Evolution Mechanism, where the authors have perfectly described the methodology from lines 333 to 346. However, the authors then go on to discuss the results they have obtained in Figure 10, lines 349-370.
The paper is very good and nothing needs to be changed, the problem is that the structure is difficult to follow for a reader of academic papers.
The conclusions are solid based on the results and the introduction describes the problem and ends with a solid objective in my opinion. Therefore, the authors should just structure the text of the experimental part correctly.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article, "Study on the Micro Mechanism of Failure Evolution of Desulfurization Gypsum-Fly Ash Fluidized Lightweight Soil Based on Discrete Element Method," deals with the study of macroscopic mechanical properties and failure evolution mechanism of desulfurization gypsum-fly ash lightweight soil and the creation of a microscale numerical model using PFC2D. The authors conducted uniaxial compression tests to determine the microscopic parameters of the model, obtaining information on the type, number, age and trend of particles in the discrete crack network. In addition, the morphology of cracks and the evolution of the propagation of light gypsum ash desulfurization soil were studied, and the failure properties of light gypsum ash desulfurization soil were evaluated using energy indices. Before publication, I recommend taking into account several aspects:
1. Please provide the chemical composition of the silt from the trial section of the Beijing-Taiwan Expressway.
2. In the article, you mention the small particle size of all raw materials (line 100) - I suggest you add a particle size analysis of the base materials to the manuscript - particle size also affects the final strength.
3. Is the information on the chemical composition and performance indices of fly ash and cement (Table 1, 2 and 3) provided in the article based on your previous research, current research for the manuscript or is it from the manufacturer? - please comment on this issue in the manuscript.
4. In Figure 2, please mark the entringite and correct the scale on the photographs as it is not very visible.
5. In the manuscript, please provide the names of the manufacturers of the equipment/software you used during the study/simulation.
6. What standards did you use when conducting the stress tests? - please include this information in the manuscript.
7. How many specimens from each series (A1, A2, A3) did you subject to compressive strength tests? What was the error of deviation of the obtained results?
8. Did you examine the Young's modulus of the obtained A1, A2 and A3 samples?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have adequately addressed my concerns in this revision and changed the manuscript according to almost all my revision notes. I think that it is suitable for publication in its present form.
Comments on the Quality of English Languageminor revision
Author Response
Comments: The authors have adequately addressed my concerns in this revision and changed the manuscript according to almost all my revision notes. I think that it is suitable for publication in its present form.
Response : Thank you very much for your suggestion. We have revised some sentences in the text again to ensure correct grammar and ease of reading.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have not taken my comments into account. The authors have written the Introduction and Conclusion sections correctly. However, the Experimental/Results/Discussion sections are mixed up and make the paper impossible to read. Given the excellent work they have done, I cannot reject it, I just ask that it fits into the academic structure, you can search the thousands of articles in Coatings or any other MPDI journal.
I will leave you with a reference where you can find out how to write scientific articles, in the form that it is now a report and not an academic article:
P. LaPlaca, A. Lindgreen, J. Vanhamme, How to write really good articles for premier academic journals, Industrial Marketing Management, 68 (2018) 202-209.
You can also see it in the instructions for authors:
https://www.mdpi.com/journal/coatings/instructions
Author Response
Comments : The authors have not taken my comments into account. The authors have written the Introduction and Conclusion sections correctly. However, the Experimental/Results/Discussion sections are mixed up and make the paper impossible to read. Given the excellent work they have done, I cannot reject it, I just ask that it fits into the academic structure, you can search the thousands of articles in Coatings or any other MPDI journal.
Response : Thank you very much for your suggestion. We have taken your advice, reviewed numerous MDPI journal articles, and borrowed the structure of one of them (article title: The Effects of Nitrogen Content on the Mechanical and Tribolological Properties of CrTaWNx Thin Films). We have changed the structure of the article to abstract, keywords, introduction, materials and methods, results, discussion, conclusion, and references to make it more in line with academic structure.
