Experimental Study of the Dynamic Characteristics and Microscopic Mechanism of Lightweight Soil Modified with Expanded Polystyrene and Sisal Fibre
Round 1
Reviewer 1 Report
REVIEW REPORT
The paper discusses the micro- and macrocharacteristics of soil modified with expanded polystyrene foam granules and sisal fibres. The issues presented in this manuscript are very important in the context of the dynamically loaded subsoil. The scope is well related to the sustainable environmental geotechnics and it is of interest to the geotechnical community.
The work is experimental-analytical in nature, the test procedure is logical. In my opinion the manuscript is interesting but not sufficiently explained and carelessly formatted without taking into account the journal's guidelines. For this reason, this study requires major modifications before it can be accepted for publication.
The basic objections to the manuscript are:
GENERAL COMMENTS (Please check all manuscript):
(1) ALL MANUSCRIPT:
– Inappropriate references to literature in the text. Please format the text and the reference to literature according to publishing guidelines. For example, it should be in the text: “Fu et al. [2] found that the EPS particle admixture (...)” instead of “Fu Renjian [2] found that the EPS particle admixture (...)”, or “Cao et al. [8] studied the early crack (…)” instead of “CAO [8] studied the early crack (…)”;
– All symbols used in Abstract (e.g. EPS), Conclusion (e.g. EPS, Ed, NMR, SEM, …) and for the first time in the main text should be preceded by the full name.
(2) TEST DESCRIPTION:
– The details of the own research are insufficient in terms of the characteristics of the soil material, the equipment of the apparatus, the test parameters, and the appropriate Standards.
(3) ALL FIGURES! – Poor quality of the graphs and inscriptions:
– The poorly visible inscriptions on the drawing (and on the axes). Please enlarge the font.
– You should standardize the axis descriptions in the drawings: parameter symbol with unit ( even such as “-”), with or without parentheses.
– Inappropriate description of the Figures with more than one photograph or graph. You should write the main title at first (a short explanatory title), then the description of the subpoints (a) …; (b) …. etc. In addition, the photographs or graphs must be described in the drawing as a), b) etc.
(4) CONCLUSIONS:
– The conclusions should be more precise. What are the practical guidelines for others? What are the Authors' further plans to develop this issue?
(5) REFERENCES:
– The References should be formatted according to publishing guidelines.
SPECIFIC COMMENTS:
(1) Introduction:
The introduction should discuss the specificity of using natural fibers in soil mixtures. How does the soil matrix interact with the fibers? What is the durability of the mixture due to the addition of organic fibers?
(2) Page 2:
“… the dynamic triaxial test was conducted with an accuracy of 0.0001 mm …”
– An accuracy of what do you mean?
(3) Page 3:
“The soil sample should be compacted in 5 layers, …”
– Why 5 layers and not 3 layers?
– What test was carried out?
– Please refer to the appropriate standard according to which the test was performed.
(4) Table 1:
– Please complete the grain size composition.
– It should be: “Specific gravity ds/-“ or “Specific gravity ds/(-)“.
– The units with or without parentheses.
(5) Page 3:
“ … the compacted density was 0.060 g/cm3.”
– How were the EPS particles compacted?
(6) Section 2.2.3:
– Please include a reference to the photo of the fibers.
– How were sisal fibers prepared for testing?
– What about the durability of the fibers in the mixture?
– How were they mixed with the soil? This is a difficult process, especially on a large scale. Was the soil dry or moist when mixing?
(7) Table 2:
– Please standardize the first line in the table (parameter name, parameter symbol, unit) as in Table 1.
– “tex” – What is this?
– “Breaking strength” – This is not a physical parameter.
– Please briefly explain the parameters presented in the Table 2.
(8) Page 4:
“Part A was to find the optimum amount of polystyrene foam using volume ratios of 0%, 5%, 10%, 15% and 20% under the test conditions of 100 kPa perimeter pressure and 1 Hz[15] to find the maximum improvement effect coefficient. Part B was to find the optimum amount of polystyrene foam with volume ratios of 0%, 5%, 10%, 15% and 20% under the same test conditions.”
– According to this description, parts A and B are identical. So what is the difference?
– This description is inconsistent with the data in Table 3.
(9) Page 4:
“… the soil samples with different sisal dosages after the cyclic loading test were first put into a drying oven at 80℃ for 48 h to completely dry …”
– The soil is normally dried at a temperature of 105℃. Why was 80℃ chosen?
(10) Tables 3 and 4:
– Please standardize the first line in the tables as in Table 1.
(11) Page 4:
It should be: “… EPS doping levels are 0%, 5%, 10%, 15% and 20% …”.
(12) Page 5:
“The magnitude of the dynamic modulus of elasticity …”
– How was the maximum (initial) value of the dynamic modulus of elasticity determined? This is an issue related to the range of small and very small strains, which requires appropriate measurement of strains. The authors do not write anything about this.
(13) Page 5:
“… reduces the strength of the clay cement structure.”
– Incomprehensible explanation. Please explain what the authors mean.
(14) Figs. 3 and 4 (p. 5), Figs. 6 and 7 (p. ?):
Incorrect order of Figures in the text, Fig. 4 is first, and then Fig. 3, and it should be the other way round. Similar situation with Figs. 6 and 7.
(15) Page 6:
“the macroscopic dynamic modulus of elasticity”, “kinematic modulus”
– Please explain these parameters?
(16) Figures 6–10, 13–14, 16, 18:
Lack of the information (in the legend to the graphs and in the title of the Figures) that it is a mixture of soil with a constant content of 5% EPS and a variable content of sisal fibers.
(17) Page 7:
“… the maximum value of Edmax, the inverse of the dynamic modulus of elasticity and Edmax curves were established …”
– How were the maximum modulus values determined experimentally?
(18) Figure 12:
– Where are the axes of the coordinate system?
– The graph shows that the amplitude was variable, is this true?
(19) Figure 14:
??? Two identical graphs!
(20) Section 4.1, 4.2:
Please provide technical parameters of the tests, e.g. frequency or others.
(21) Figure 16:
Please describe in detail the difference between the two drawings and correctly title Figure.
Good luck!
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
The paper aims to show the dynamic behavior of clay modified with EPS and sisal fiber by experimental results. The authors performed dynamic triaxial tests, nuclear magnetic resonance, and SEM analyses. Several issues need to be cleared in the manuscript. I am reporting some comments/questions to be addressed.
The authors mention in the first paragraph of the introduction that clay is the material widely used in building foundations due to its good mechanical properties. This is a very wrong description. Clay is always removed from the foundation soil, which usually causes consolidation problems. Also, this paper aims to improve the dynamic properties of the clay material. If it shows good mechanical properties, what is the aim of enhancing this soil?
In the introduction, the authors only listed the references. There is no information about the findings of these researchers. What did they find? How do sisal fibers affect the sandy and clayey soils? Based on the previous research, which soil type can be improved with sisal fibers?
“The microstructure and pore characteristics of EPS-sisal-modified lightweight soils were analyzed from a microscopic point of view through nuclear magnetic resonance and scanning electron microscopy to provide a reference basis for practical related projects.” Did the authors perform the nuclear magnetic resonance and scanning electron microscopy only to be a reference for practical related projects? If this is the case, no example is given in the paper regarding the practical projects. I also believe that this is not the only reason. The introduction needs to be rewritten based on the comments given above.
What is the type of clay used in the experiments? Is it illite, montmorillonite etc? Any organic content? It can be good to show the SEM view of the original clay material.
Table 1: The unit of natural density is not correct.
The subtitles 2.2.2 and 2.2.3 are not needed to be given under the subtitles. How 5mm sisal fiber was obtained? It can be good to write the range instead of giving the exact dimensions here.
It is not clear how the soil-remolded samples were prepared. What is the stiffness of the clay and mixtures? What is the void ratio of the samples before starting the test?
Why is EPS given in volume and sisal fiber given in mass in the mixture?
How can one be sure that soil is saturated in 8 hours? Did you check the saturation?
Were SEM tests performed before or after the dynamic test? No information is given. If it is after the dynamic test, how the undisturbed sample is obtained? Need more information.
Figure 2 and Figure 5: Please write the EPS and sisal fiber percentages on the figures.
Figures 3, 4, 6, and 7: The numbers on the axes are not possible to read, and the legend as well.
No need to give Figure 11. It is a well-known hysteresis loop.
Figure 12: Need to show the axes.
On page 9, the equation to find the total energy is given two times, and the explanation of the equation is also duplicated.
On page 10: “…time, and all the maximum deformation values…” What does the maximum deformation value refer to here?
Figure 14 seems to show two similar things.
Table 3. Is sisal quality in percentage?
Figure 1 is so blurry that nothing can be understood from the photos.
In the last paragraph of the introduction. What does “complex force” mean?
The abstract is too extended, and detailed information needs to be shortened.
Figure 18: SEM images show only a tiny portion of the sample. What about the other parts of the sample? More view is necessary to have a conclusion here. Are these test results before or after the dynamic loading?
The conclusion is so limited. The abstract is more extended than the conclusion. Please mention the practical usage of this method. In (5) “the best structural model” What does the best structural model mean?
Minor editing of English language required
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Dear Authors,
Here are my general comments.
- References are not adequately referred in text
- All figures needs to be larger. They are hard to read.
- Page 2. What is the obvious effect Fu Renjian found? In references it is stated as FU Renjian, so in text it should be only “FU”. Use reference manager for citations if necessary.
- Page 2: Sisal fibre has a high yield for what?
- Figure 1 is small and hard to read!
- More details about clay is needed. What about the hydrometer analysis? What is the percent of clay particles?
- Are the test stress-controlled or strain controlled?
- Add a multiplication symbol in equations (3) and (4)
- Equation (6) is valid for symmetrical loop. Is your loop in one cycle symmetrical?
- Figure 12. From presented figure I can see some loops. How are them stress-strain? Where are the axis?
- Figure 14. The results are based on what cycle?
- I cannot see the relevance of section 4. Please elaborate why is it necessary?
English language is good written but it lack some specific terms that Author's need to address.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I thank the Authors for taking into account many of my comments and suggestions. However, on the other hand, many comments were omitted. Additionally, some explanations addressed to the reviewer should be included in the text of the paper. Therefore, the manuscript still requires major revisions. I marked my comments in the attached copy of the Author's Response file.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
The revisions are acceptable.
Author Response
Thank you very much for your recognition of our answer, based on your first instance comments, we have also made further improvements and additions, thank you again for your guidance and recognition!
Reviewer 3 Report
Dear Authors,
My comments are bellow your statements by points.
【Point 1】References are not adequately referred in text
-All figures needs to be larger. They are hard to read.
Response 1: Thank you very much for your valuable opinions. I have added a description of the references based on the structure of the article. For all the icons in the article, I have made improvements.
Reviewer: Figures are still unclear, especially Fig 15., 16. And 17. Why have you decided to place Figures 3, 4, 6 and 7 in two columns?
【Point 2】Page 2. What is the obvious effect Fu Renjian found? In references it is stated as FU Renjian, so in text it should be only “FU”. Use reference manager for citations if necessary.
Reviewer: There is still inconsistency in the citation!
-Page 2: Sisal fibre has a high yield for what?
Response 2: Thank you very much for your valuable opinions. I have made changes to the citation of references. The high yield of sisal fibre is due to its low cost and ease of cultivation and reproduction.
【Point 3】Figure 1 is small and hard to read!
-More details about clay is needed. What about the hydrometer analysis? What is the percent of clay particles?
Response 3: Thank you very much for your valuable opinions, I have made changes to Figure 1. We have revised the basic relevant information about clay in the text.
Reviewer: Free expansion is not a common parameter for clays. What about fine content and clay particle content?
【Point 4】Are the test stress-controlled or strain controlled?
-Add a multiplication symbol in equations (3) and (4)
Response 4: Thank you very much for your valuable opinions,.This test is an experimental study by controlling the dynamic stresses.
Reviewer: Equation (3) and (4) need to be clearer. Just add the multiplication symbol.
【Point 5】Equation (6) is valid for symmetrical loop. Is your loop in one cycle symmetrical?
-Figure 12. From presented figure I can see some loops. How are them stress-strain? Where are the axis?
Response 5: Thank you very much for your valuable opinions. Each cycle of the loop is symmetrical. I have modified this diagram and included the axes.
Reviewer: Equation (6) is valid for symmetrical loop. Is your loop in one cycle symmetrical and if so, around what point?
【Point 6】Figure 14. The results are based on what cycle?
Reviewer: You have not answered my question.
-I cannot see the relevance of section 4. Please elaborate why is it necessary?
Response 6: Thank you very much for your valuable opinions. I have made changes to Figure 14. Nuclear Magnetic Resonance (NMR) and Scanning Electron Microscopy (SEM) tests are designed to validate, interpret, analyse and explore the results of studies on the dynamic properties of soils at the microscopic level.
Reviewer: I still do not see the relevance of this chapter.
No comment
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
I have included my final comments in the attached file. After completing them, the paper may be published.
Comments for author File: Comments.pdf
Author Response
Thank you very much for your final feedback. We have made appropriate changes based on your input! Once again, we sincerely appreciate your guidance throughout these three stages, and we have benefited greatly from it!
Reviewer 3 Report
Thank you for your comments.
No comments
Author Response
Thank you very much for your guidance and suggestions during this period; we have greatly benefited from them! We have made further improvements based on your previous comments. Once again, thank you for your guidance!
