Modeling Flexural and Compressive Strengths Behaviour of Cement-Grouted Sands Modified with Water Reducer Polymer

Round 1

Reviewer 1 Report

Dear Authors,

Thank you very much for your manuscript. I have several comments as follows and I hope that these can help improve your manuscript:

1. Repeated abbreviation for "compressive strength - CS" (line 20, line 21);
2. What does "CM" stand for? (line 42);
3. It's necessary to have a definition of σ_c (line 56) and d₁₀ (line 57);
4. Reference No. [4] lacks of information (line 354);
5. "...behavior cement ..." (line 65) should be replaced by "...behavior of cement ...";
6. "PSD and Gs" (line 77, 78) needs to be expressed or explained;
7. What does "SEM" stand for? (line 83);
8. It would be better if Figures 5a and 5b have the same size. The same situation for Figures 6a and 6b;
9. "Flowchart methodology" (line 128): I suggest that "Flowchart of methodology";
10. Figure 1 (page 3): lack of the connection between "ASTM standard" and "Cylindrical compressive strength"; abbreviation in advance or legends for "NLR" and "LR" are necessary;
11. Table 2 (page 6): what is the unit of CS?; "Flow and CS ..." (line 169) should be replaced by "Flow time and CS...";
12. "The flow cone method" (line 171): it would be better if a brief description of the method is showed here;
13. "P" in equations 1 to 6, it is "Polymer" as I understood. However, there was no definition, note or legend of "P";
14. "When fine-grained sand ... the w/c was increased." (line 197-198): this statement needs to be justified by data or at least more explanation;
15. "The CG prepared ... was between 0.57 - 0.6," (line 199-201): I see that this statement is only true with w/c = 0.57 as described in Table 2. Please double check this;
16. "..., but the coarse-grained sand ... was between 0.5 - 0.53.": it 's better to mention in detail here with data and/or to indicate which "sand no." here;
17. "...; finer-grained sand produces a more homogeneous CG mixture than coarser-grained sand." (line 203-204): I think this is obviously true. I am not sure if this is the result of your research or it is just a statement in general;
18. "..., adding polymers reduced the water content of CG by 20% to 54% to achieve the necessary flowability, as shown in Figure 7. Depending on the types of sand and the flow period, adding the 0.12 % polymer reduced the w/c of CG by 23 to 50 per-cent." (line 215 - 218): please justified by data or more explaination;
19. What does "PC" stand for? (line 229);
20. To have a better visual comparison, Figure 9a and 9b (page 10) should be displayed as the same scale.

Best regards.

Author Response

Reviewer 1

Thank you very much for your manuscript. I have several comments as follows and I hope that these can help improve your manuscript:

1. Repeated abbreviation for "compressive strength - CS" (line 20, line 21); Response: Fixed and Thanks.  
2. What does "CM" stand for? (line 42); Response: it means cementitious materials (CM). Provided and thanks.
3. It's necessary to have a definition of σ_c (line 56) and d₁₀ (line 57); Response:  Provided and thanks.
4. Reference No. [4] lacks of information (line 354); Response:  The ref. 4 has been changed.
5. "...behavior cement ..." (line 65) should be replaced by "...behavior of cement ..."; Response:  Corrected and thanks.
6. "PSD and Gs" (line 77, 78) needs to be expressed or explained; Response:  provided as you suggested.
7. What does "SEM" stand for? (line 83); Response:  Scanning Electron Microscopy (SEM). Provided based on your suggestion.
8. It would be better if Figures 5a and 5b have the same size. The same situation for Figures 6a and 6b; Response:  The figures are almost the same size thanks for your comments.
9. "Flowchart methodology" (line 128): I suggest that "Flowchart of methodology"; Response:  Done and thanks.
10. Figure 1 (page 3): lack of the connection between "ASTM standard" and "Cylindrical compressive strength"; abbreviation in advance or legends for "NLR" and "LR" are necessary; Response:  The connections are fixed, and the abbreviation is also provided. Thanks.
11. Table 2 (page 6): what is the unit of CS?; "Flow and CS ..." (line 169) should be replaced by "Flow time and CS..."; Response:  the units are provided, and “flow time and CS” is modified. Thanks.
12. "The flow cone method" (line 171): it would be better if a brief description of the method is shown here; Response:  more information about the flow cone test has been added to the paper.
13. "P" in equations 1 to 6, it is "Polymer" as I understood. However, there was no definition, note or legend of "P"; Response:  the  “P = polymer conten (%)” is added to the text.
14. "When fine-grained sand ... the w/c was increased." (line 197-198): this statement needs to be justified by data or at least more explanation; Response:  The whole paragraph has been modified and clarified based on your suggestion.
15. "The CG prepared ... was between 0.57 - 0.6," (line 199-201): I see that this statement is only true with w/c = 0.57 as described in Table 2. Please double check this; Response:  . In the case of a high water/cement ratio ranged between 0.57-0.6, the cement grout prepared with fine-grained sand (Sand # 2) found the highest compressive strength at 28 days compared to other mixes but in the lowest water/cement ratio ranged between 0.5-0.53 the coarse-grained sand obtained the highest compressive strength at 28-days of curing compared to the other mixes. The paragraph has been check it and modified.
16. "..., but the coarse-grained sand ... was between 0.5 - 0.53.": it 's better to mention in detail here with data and/or to indicate which "sand no." here; Response:   “ Sand #5” is added to the text.
17. "...; finer-grained sand produces a more homogeneous CG mixture than coarser-grained sand." (line 203-204): I think this is obviously true. I am not sure if this is the result of your research or it is just a statement in general; Response:    Yes it this study results. At a high water/cement ratio, the finer-grained sand leads to a more uniform cement grout mixture than coarser-grained sand due to the smaller surface area of the finer-grained sand relative to that of the coarser-grained sand.
18. "..., adding polymers reduced the water content of CG by 20% to 54% to achieve the necessary flowability, as shown in Figure 7. Depending on the types of sand and the flow period, adding the 0.12 % polymer reduced the w/c of CG by 23 to 50 per-cent." (line 215 - 218): please justified by data or more explaination; ; Response:    more explanation is added to the text.
19. What does "PC" stand for? (line 229); Response:    PC= Portland cement.
20. To have a better visual comparison, Figure 9a and 9b (page 10) should be displayed as the same scale. Response:    Agree with the comment. And it is fixed.

Reviewer 2 Report

The reviewed manuscript presents the various methods comparison of testing the strength of grouts with polymer admixture and aggregate with different particle size using. This comparison also included the fit of individual test methods to different mathematical models. Unfortunately, the quality of this paper should be assessed as very low. First of all, despite the fact that the Ators compared research methods, they did not describe them (comment 18). It is not known how and on what samples the tests were carried out. The results of these studies have been discussed very briefly without accurate analysis. In the case of the XRD analysis, it was misinterpreted. The article was also written in incorrect English, which additionally hinders its understanding (some language errors examples will be presented in the later part of review).

 

Below is a detailed list of comments:

 

1.The title is incorrect, it was spelled incorrectly - stylistic errors make it confusing and do not match to the paper content:

- it is difficult to understand what the Authors mean when they write "Experimental and Modeling Evaluations to Predict ...",

- it was the polymer that was added to the grout, not the grout to the polymer.

 

2. Provide full Authors affiliation details - addresses are missing

 

3. Abstract - it was incorrectly prepared, contrary to the "Instructions for Authors"

- the aim of article was presented too briefly,

- the test methods were not presented clearly - only the compressive strength test was mentioned. Information about flexural strength tests included in the article title are mentioned only in the last sentence. There was no mention about the flow test or SEM,

- specify which polymers were the research subject,

- l.20-25 the information from these two sentences is misleading. The Authors state twice that they achieve the highest strength - probably it is about testing various mortars, but this does not result from these sentences (due to an incorrect structure),

- l.21 do not need to explain the "CS" abbreviation for the  second time.

 

4. Keywords - are too general, e.g. sand, strengths. I suggest adding: cement grout.

 

5. l.38-40 “To cover the sand particles, a high flowable CG is the main goal .” - this sentence is incomprehensible. Why is this the goal? The goal of what? A sentence taken out of context, because the cement substitute was previously described. Shouldn't it be combined with the following sentence: “As a result, the component's CS and bonding strengths will greatly enhance”? Or rather, the results described in this sentence relate to the use of cement substitutes?

 

6. l.40 "creation" - change the word.

 

7. I.42 "CM" - unexplained abbreviation (Cement Mortar?)

 

8. l.41-44 I do not agree with the Authors' claim that water reducers (plasticizers and superplasticizers) used in the concrete technology shortened the setting time (often the opposite effect is true). The incorrectly cited references [6-8]; they do not concern the influence of admixtures on the properties of such materials at all.

 

9. l.45 "When a CM was prepared with coarser sand grading than fine sand" - it is obvious that coarse sand has coarser graining than fine sand, so I see no reason to write "..than fine sand".

 

10. l.50-53 The Authors should explain why the performance of the compressive strength test with two different methods is important - what is it supposed to prove? Why was the compressive strength tested with two methods and the flexural strength with only one method? It would also be necessary to explain why the given methods were chosen and, of course, provide which methods were chosen.

 

11. l.65 Incorrectly selected references [10-12] - these items do not describe the polycarboxylate admixtures steric effects.

 

12. l.65-66 please explain the relation between polymer pH and solids content. What is the significance of this for the performed tests and how was it determined.

 

13. Figure 1 is not described in the text - The Authors do not explain what it presents.

 

14. Figure 3 instead of "mineralogical composition" I recommend using "phase composition". How was the quantified phase composition determined? Based on the oxide composition or on the basis of the diffraction pattern?

 

14. l73-74 Information about used polymer should be included in the appropriate section (2.1.1.), not in the cement description (2.1.2.). Due to the diversity of materials and the specificity of the XRD tests performed, the information about the peak intensities in different materials is not important.

 

16. Figure. 2 Phase identification on the presented diffraction patterns raises doubts:

- Figure 2a Brushit has a very intense peak of around 21 °2θ, not 19, while Cassiterite has a most intense peak of around 26.5 °2θ, not 23,

- Figure 2b Quartz was misidentified. The most intense quartz peaks should be around 26 and 21 °2θ. Due to the lack of the 26 °2θ peak, it can be concluded that quartz is not present in this sample. The peaks attributed to quartz are most likely derived from gypsum and portlandite (possibly caused by moisture in the cement). Also unidentified are the intense peaks in the diffraction pattern, e.g. the peak of brownmillerite around 33.8 °2θ.

 

17. l.77-78 explain the "Gs" and "PSD" signs.

 

18. Section 2.2. Methods section was inappropriately prepared. There is no essential information on the performed tests, which prevents correct interpretation of the results. Thus, the section content is inconsistent with its title:

- only the brief information on the performed XRD (2.2.1) and SEM (2.2.2) tests was provided, without information about the equipment used for the tests - XRD and incomplete data on SEM, sample preparation or measurement parameters.

- in section 2.2., the methods of flexural and compressive strength tests, essential for this work, were not described at all. From the whole work it follows that they were carried out on the basis of some ASTM and BS standards, not precisely specified. There are also no specific standards in the references.

 

19. Table 2. Move to section 3. The results discussed in later sections should not be given here.

 

20. l.73 incorrect numbering of sections. After section 2.2. there is section 2.7. I believe that section 2.7 "Data analysis" should be placed as section 3. However, this section lacks the description and justification of the selected models - only equations are given, additional references to the literature are given for the non-linear model, but not for the linear model.

 

21. l.164 [13] it is not the ASTM C 938 standard in the references.

 

22. Section 3.1. the description of the w/c-sand graining-flow relationship is incomprehensible (it was poorly formulated or translated):

- l.198 how was fine sand used to "achieve equal flowability"? What do the Authors mean by "equal flowability"?

- l.199 w/c did not increase (incorrect term), because the Authors assumed that four constant levels of w/c were studied.

 

23. l.202-204 Did the Authors investigate the surface area to justify their statement? It is known that usually the finer material has a larger outer surface area than the coarser material. To explain the differences in fluidity, one can also pay attention to the aggregate particle shape and size.

 

24. l.208-210 premature conclusion. At this stage, it should not be said which grout is the best. The only thing that can be said is which grout have the best flow - which is obvious.

 

25. l.223-228 the content of the paragraph on the phase analysis is inconsistent with the section title. When writing chemical formulas, use a subscript for the digits.

 

26. Figure 5 and 6 should be transferred from section 2.2.2. to 3.3. All figures and tables should be placed in the section in which they are discussed.

 

27. Figure 9b is not described in the text.

 

28. Section 3.4.2. I think the description is too superficial.

 

29. Figure 11 - errors in the parentheses in the Y axis description.

 

30. l.274 "muscularly" - incorrect word.

 

31. l.289 "cube"? In l.25 only the study of prismatic and cylindrical samples was mentioned.

 

32. l.294 How do the Authors understand the concept of "typical flexural strength"? I notice that there are different polymeric admixtures - not just water reducers that can affect the grout properties differently.

 

33. The article lacks a detailed results discussion in the light of contemporary literature. Section 3 presents only the results without accurate analysis.

 

34. l.323 the term "electronic microscopy" is incorrect - it may be "electron microscopy"

 

35. References - were prepared incorrectly, among others, due to:

- the bibliographic data are provided in the way inconsistent with the guidelines in the "Instructions for Authors",

- items [1] and [4] are the same item, only in [4] there are only the names of the Authors not presented in [1],

- from comments 8 and 11, it follows that the literature was not properly selected.

 

36. There are various spelling mistakes in the paper, incorrect vocabulary (e.g., comments 6, 30 and 34), sentence structure, or incorrect spacing (e.g., l.217, 288, 299).

Author Response

Reviewer 2

 

Comments and Suggestions for Authors

The reviewed manuscript presents the various methods comparison of testing the strength of grouts with polymer admixture and aggregate with different particle size using. This comparison also included the fit of individual test methods to different mathematical models. Unfortunately, the quality of this paper should be assessed as very low. First of all, despite the fact that the Ators compared research methods, they did not describe them (comment 18). It is not known how and on what samples the tests were carried out. The results of these studies have been discussed very briefly without accurate analysis. In the case of the XRD analysis, it was misinterpreted. Response: The whole paper, including the text with the explanations of the test, has been modified and explained to be clear for the readers. After responding to the reviewer comments, the paper is satisfied with the high-quality journals.

The article was also written in incorrect English, which additionally hinders its understanding (some language errors examples will be presented in the later part of review).

Responses: Thanks for the comment, The texts, including the abstract, tables, and figures, have been edited and organized in terms of discussions, conversions, spelling, nouns, variety, word order, punctuations, prepositions, and fluency. The paper has been modified to satisfy the scientific journal requirements, more functional models have been added to justify the results.
 Below is a detailed list of comments:

 1.The title is incorrect, it was spelled incorrectly - stylistic errors make it confusing and do not match to the paper content: - it is difficult to understand what the authors mean when they write "Experimental and Modeling Evaluations to Predict ...",- it was the polymer that was added to the grout, not the grout to the polymer.  Responses: The title has been modified based on the reviewer 2’s suggestion

2. Provide full Authors affiliation details - addresses are missing:  Responses: Correct affiliations have been added. Thanks.
3. Abstract - it was incorrectly prepared, contrary to the "Instructions for Authors". Responses: The abstract has been modified based on your suggestion.

- the aim of article was presented too briefly. Responses: The aim of the study has been modified based on your suggestion.

- the test methods were not presented clearly - only the compressive strength test was mentioned. Information about flexural strength tests included in the article title are mentioned only in the last sentence. There was no mention about the flow test or SEM. Responses: The test methods of the study have been modified and highlighted in the text. Thanks for the time and effort.

- specify which polymers were the research subject, Responses: The Polycarboxylate ether-based polymer was used in this study, consisting of one main linear backbone with side carboxylate groups. The groups of carboxylates are the anchoring groups by which these admixtures are added to modify the cement. The solid content of Polycarboxylate ether-based polymer with a pH of 10  is greater than 97%.

- l.20-25 the information from these two sentences is misleading. The Authors state twice that they achieve the highest strength - probably it is about testing various mortars, but this does not result from these sentences (due to an incorrect structure). Responses: Dear reviewer, the sentence has been modified based on the detailed response to the reviewers. Thanks.

- l.21 do not need to explain the "CS" abbreviation for the  second time. Responses: The CS is compressive strength, and the abbreviation has been added to the paper. Thanks.

4. Keywords - are too general, e.g. sand, strengths. I suggest adding: cement grout.

 Responses: Thanks for the suggestion. It is added.

5. l.38-40 “To cover the sand particles, a high flowable CG is the main goal .” - this sentence is incomprehensible. Why is this the goal? The goal of what? A sentence taken out of context, because the cement substitute was previously described. Shouldn't it be combined with the following sentence: “As a result, the component's CS and bonding strengths will greatly enhance”? Or rather, the results described in this sentence relate to the use of cement substitutes?  Responses: the sentence has been modified based on your suggestion.
6. l.40 "creation" - change the word. Responses: Sure, and it is done.
7. I.42 "CM" - unexplained abbreviation (Cement Mortar?) Responses: it means cementitious materials, and it is explained in the text.
8. l.41-44 I do not agree with the Authors' claim that water reducers (plasticizers and superplasticizers) used in the concrete technology shortened the setting time (often the opposite effect is true). The incorrectly cited references [6-8]; they do not concern the influence of admixtures on the properties of such materials at all. Responses: Agree with the comment, and the right references have been used in [6, 7, 8].
9. l.45 "When a CM was prepared with coarser sand grading than fine sand" - it is obvious that coarse sand has coarser graining than fine sand, so I see no reason to write "..than fine sand". Responses: Removed as you suggested.

 

10. l.50-53 The Authors should explain why the performance of the compressive strength test with two different methods is important - what is it supposed to prove? Why was the compressive strength tested with two methods and the flexural strength with only one method? It would also be necessary to explain why the given methods were chosen and, of course, provide which methods were chosen.

Response:

As it is known that the shape of the sample is affecting the compressive strength of the materials. And Since the BS standard uses prismatic mold (40 x 40 x 160 mm) and ASTM standard cylindrical mold (100 x 200 mm), the correlation between these two most common standards is needed. The cube is more stable in shape, and the strength will be higher than the cylinder. The broken pieces of the prism will exhibit higher strength than the cubes. The shape and size will govern the strength of broken pieces, as well as they would have gone through the test so that they may contain many micro cracks. Different shapes are subjected to different levels of influences due to eccentricity, lateral confinement, distribution of aggregates, and internal defects. Different countries/organizations have issued different standard testing methods to regulate the testing to evaluate the material with the same criterion and test method in that country/region. The test results of compressive strength are also dependent on the test specimen's dimension, referred to as the size effect. In nature, the size effect is also associated with the influence of eccentricity, lateral confinement, distribution of aggregates, internal defects, etc.

Compression loads are applied in the casting direction for the cylinder and perpendicular to the casting direction for the cubes. Because both cylinder and cubes are cast and consolidated in multiple layers, the direction of loading is essential in the relationship between cylinder strength and cube strength. When cylinders are loaded, each casting layer occupies an entire cross-section and receives the testing machine's total load. Each layer extends from top to bottom when cubes are loaded and gets a portion of the total load [1].

Compared with the cube test, the advantages of the cylinder are less end restraint and a more uniform distribution of stress over the cross-section; for these reasons, the cylinder strength is probably closer to the true uniaxial compressive strength of cement-based materials than the cube strength. According to all experimental data of the relation between cube and cylinder stated that the cylinder strength of hardened cement-based materials is not a constant value of 0.8 times the cube strength because it depends upon so many factors water-cement ratio, quality of sands (grading, surface texture, size, shape, strength, and stiffness), cement content and the period [2, 3, 4] below: 

1. Malaikah, A. S. (2005). Effect of specimen size and shape on the compressive strength of high strength concrete. Pertanika J. Sci. Technol, 13(1), 87-96.
2. Hamad, A. J. (2017). Size and shape effect of specimen on the compressive strength of HPLWFC reinforced with glass fibres. Journal of King Saud University-Engineering Sciences, 29(4), 373-380.
3. Kumari, R. (2015). Review paper based on the relation between the strength of concrete cubes and cylinders. International Journal of Engineering Research and Applications, 5(8), 52-54.
4. Elwell, D. J., & Fu, G. (1995). Compression testing of concrete: cylinders vs. cubes (No. FHWA/NY/SR-95/119).
5. l.65 Incorrectly selected references [10-12] - these items do not describe the polycarboxylate admixtures steric effects. Responses: Agree with the comment, and the right references have been used in [10, 11, 12].
6. l.65-66 please explain the relation between polymer pH and solids content. What is the significance of this for the performed tests and how was it determined. Responses: data were provided from the supplier, and the authors did not do the tests.
7. Figure 1 is not described in the text - The Authors do not explain what it presents. Responses: The detailed explanation for Fig. 1 has been added to the paper based on your suggestion.
8. Figure 3 instead of "mineralogical composition," I recommend using "phase composition". How was the quantified phase composition determined? Based on the oxide composition or on the basis of the diffraction pattern? Responses: The phase composition of cement was determined by X-ray powder diffraction, petrographic examination, and electron microprobe analysis.
9. l73-74 Information about used polymer should be included in the appropriate section (2.1.1.), not in the cement description (2.1.2.). Due to the diversity of materials and the specificity of the XRD tests performed, the information about the peak intensities in different materials is not important. Responses: The sections and the polymer information have been explained and modified based on the reviewer's comments.
10. Figure. 2 Phase identification on the presented diffraction patterns raises doubts: Responses: All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results.

 

 

 

 

- Figure 2a Brushit has a very intense peak of around 21 °2θ, not 19, while Cassiterite has a most intense peak of around 26.5 °2θ, not 23,  - Figure 2b Quartz was misidentified. The most intense quartz peaks should be around 26 and 21 °2θ. Due to the lack of the 26 °2θ peak, it can be concluded that quartz is not present in this sample. The peaks attributed to quartz are most likely derived from gypsum and portlandite (possibly caused by moisture in the cement). Also unidentified are the intense peaks in the diffraction pattern, e.g. the peak of brownmillerite around 33.8 °2θ. Responses: A similar results were found from previously published studies [ 8, 11]. Really appreciate your effort to improve the quality of this paper. All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results.

17. l.77-78 explain the "Gs" and "PSD" signs. Responses: The symbols have been explained.
18. Section 2.2. Methods section was inappropriately prepared. There is no essential information on the performed tests, which prevents correct interpretation of the results. Thus, the section content is inconsistent with its title: Responses: The Methodology section has been justified and modified based on your suggestion.

- only the brief information on the performed XRD (2.2.1) and SEM (2.2.2) tests was provided, without information about the equipment used for the tests - XRD and incomplete data on SEM, sample preparation or measurement parameters. Responses: The Methodology section, including XRD and SEM tests, has been justified and modified based on your suggestion.

- in section 2.2., the methods of flexural and compressive strength tests, essential for this work, were not described at all. From the whole work it follows that they were carried out on the basis of some ASTM and BS standards, not precisely specified. There are also no specific standards in the references. Responses: The standards and the tests information have been added to the paper.

19. Table 2. Move to section 3. The results discussed in later sections should not be given here. Responses: Done as you suggested. Thanks
20. l.73 incorrect numbering of sections. After section 2.2. there is section 2.7. I believe that section 2.7 "Data analysis" should be placed as section 3. However, this section lacks the description and justification of the selected models - only equations are given, additional references to the literature are given for the non-linear model, but not for the linear model. Responses: All the section numbers have been corrected. Thanks

 

 

 

21. l.164 [13] it is not the ASTM C 938 standard in the references.

 Responses: Agree with comments since the ASTM C 938 was used in the [13], that’s why the authors preferred to support the test with [13], which was the same test procedure was conducted.

22. Section 3.1. the description of the w/c-sand graining-flow relationship is incomprehensible (it was poorly formulated or translated): Responses: The information in the section has been modified. Thanks

- l.198 how was fine sand used to "achieve equal flowability"? What do the Authors mean by "equal flowability"? Responses: After modifying the sentence, the whole section was also modified

- l.199 w/c did not increase (incorrect term), because the Authors assumed that four constant levels of w/c were studied. Responses:  Based on your comments, most of the sentences have been modified, and thanks for your valid comments.

23. l.202-204 Did the Authors investigate the surface area to justify their statement? It is known that usually the finer material has a larger outer surface area than the coarser material. To explain the differences in fluidity, one can also pay attention to the aggregate particle shape and size. Responses: Surafe area of the materials was not considered in this study.
24. l.208-210 premature conclusion. At this stage, it should not be said which grout is the best. The only thing that can be said is which grout have the best flow - which is obvious. Responses: I agree with the comment that the best grout is high flowable with high strength early.
25. l.223-228 the content of the paragraph on the phase analysis is inconsistent with the section title. When writing chemical formulas, use a subscript for the digits. Responses: All chemical formuls have been checked in terms of writing. Thanks for the comments.
26. Figure 5 and 6 should be transferred from section 2.2.2. to 3.3. All figures and tables should be placed in the section in which they are discussed. . Responses: Done based on your suggestion.
27. Figure 9b is not described in the text. Responses: Fig. 9b added to the text.
28. Section 3.4.2. I think the description is too superficial. Responses: The section has been modified based on your suggestion.
29. Figure 11 - errors in the parentheses in the Y axis description. Responses: Fixed and Thanks.
30. l.274 "muscularly" - incorrect word. Responses: Fixed and Thanks.
31. l.289 "cube"? In l.25 only the study of prismatic and cylindrical samples was mentioned. Responses: Fixed and Thanks.
32. l.294 How do the Authors understand the concept of "typical flexural strength"? I notice that there are different polymeric admixtures - not just water reducers that can affect the grout properties differently. Responses: Agree with comment. The word “typical” means that only two curing age results have been presented in Fig. 13.
33. The article lacks a detailed results discussion in the light of contemporary literature. Section 3 presents only the results without accurate analysis. Responses: After responding to the reviewer comments, especially reviewer #2, the paper is stratified the high-level journal. Thanks for your time and efforts.
34. l.323 the term "electronic microscopy" is incorrect - it may be "electron microscopy" Responses: Fixed and Thanks.
35. References - were prepared incorrectly, among others, due to: - the bibliographic data are provided in the way inconsistent with the guidelines in the "Instructions for Authors",- items [1] and [4] are the same item, only in [4] there are only the names of the Authors not presented in [1], Responses: Fixed and Thanks.

from comments 8 and 11, it follows that the literature was not properly selected. Responses: Fixed and Thanks.

36. There are various spelling mistakes in the paper, incorrect vocabulary (e.g., comments 6, 30 and 34), sentence structure, or incorrect spacing (e.g., l.217, 288, 299). Responses: Thanks for the comment, The texts, including the abstract, tables, and figures, have been edited and organized in terms of discussions, conversions, spelling, nouns, variety, word order, punctuations, prepositions, and fluency.

Reviewer 3 Report

Comments on the manuscript “Experimental and Modeling Evaluations to Predict the Flexural and Compressive Strengths of Cement-Based Grout Incorporated Polymers” by W. Mahmood, A. S. Mohammed, P. G. Asteris, R. Kurda, D. J. Armaghani submitted to Applied Sciences.

 

The paper presents and discusses interesting data about mechanical properties of cement grout with the addition of polymer. The research results presented in the article may be of interest to people involved in civil engineering. Unfortunately the paper is not well presented. I tried on several occasions to read it and gave up as I simply became lost in the text. I am convinced that the work should not be published in its current form. In my opinion, it would be the best to rewrite the article again. The corrected work should be reviewed again. Hereafter are my main comments:

1. When a symbol or abbreviation first appears in the text, it must be explained (examples of unexplained symbols: CM (line 42), sf (line 45), sc (line 56), d10 (line 57) and many other! It would also be helpful to add a list of symbols.

2. Page 2, lines 63-64: “In this study, a water reducer polymer with one linear backbone consists of side groups of carboxylate.” Please provide the polymer name that was used in the tests.

3. Page 2, lines 68-69: “Figure 2 (a) shows the Xray Diffraction (XRD) test results on the cement and polymer which are utilized in this research.”; page 2, lines 71-75: “Figure 2(b) shows XRD test of OPC. Figure 3 shows the mineralogical and chemical compositions of the cement. The peak intensity of the water reducer polymer is between 1500 and 2000, according to Figure 2 (a), but the peak intensity of the cement is about 300, as shown in Figure 2(b).”; page 2, lines 77-78: “In this research, five sand with different grading were used. Figure 4 shows the PSD and Gs of the sands utilized, which are also shown in Table 1.” Page 2, lines 81-82: “At a temperature of 25°C, the chemical composition of water reducer polymer and cement was investigated as shown in Figure 2”; pages 2, lines: 86-87: “…and cement-grouted sand with microstructures characterization is presented in Figures 5 and Figure 6.”. The study results should be reported in the section “3. Result and analysis”. In section “2. Materials and Methods" used materials, equipment and methodology should be described.

4. „Figure 1. Flowchart methodology”: The flowchart should be described in the text.

5. The caption of figures 8; 9; 10; 11; 13 and 14 should be corrected. The description must explain what is shown in the figure a; b and c.

6. In the paper, there is no information on measurement errors and statistical analysis of results. This information should be included in the text.

7. The English needs careful editing. The editing services of a native English speaker could easily address this point.

 

Comments for author File: Comments.pdf

Author Response

Reviewer 2

The paper presents and discusses interesting data about mechanical properties of cement grout with the addition of polymer. The research results presented in the article may be of interest to people involved in civil engineering. Unfortunately the paper is not well presented. I tried on several occasions to read it and gave up as I simply became lost in the text. I am convinced that the work should not be published in its current form. In my opinion, it would be the best to rewrite the article again. The corrected work should be reviewed again. Hereafter are my main comments: Response: Thanks for the time and efforts spent in the reviewing process. The paper, including text, figures, and tables, has been modified based on the reviewer's comments. After the modification, the paper is satisfied the journal readers.

1. When a symbol or abbreviation first appears in the text, it must be explained (examples of unexplained symbols: CM (line 42), sf (line 45), sc (line 56), d10 (line 57) and many other! It would also be helpful to add a list of symbols. Response: CM means cementitious materials. Most of the simples in the text have been identified and highlighted in the paper.

1. Page 2, lines 63-64: “In this study, a water reducer polymer with one linear backbone consists of side groups of carboxylate.” Please provide the polymer name that was used in the tests.  Response: The name of the polymer is added to the text.

1. Page 2, lines 68-69: “Figure 2 (a) shows the Xray Diffraction (XRD) test results on the cement and polymer which are utilized in this research. Response: Modified, and thanks.

 page 2, lines 71-75: “Figure 2(b) shows XRD test of OPC. Response: Modified, and thanks.

Figure 3 shows the mineralogical and chemical compositions of the cement. The peak intensity of the water reducer polymer is between 1500 and 2000, according to Figure 2 (a), but the peak intensity of the cement is about 300, as shown in Figure 2(b). Response: Modified, and thanks.

page 2, lines 77-78: “In this research, five sand with different grading were used. Figure 4 shows the PSD and Gs of the sands utilized, which are also shown in Table 1. Response: Modified, and thanks.

Page 2, lines 81-82: “At a temperature of 25°C, the chemical composition of water reducer polymer and cement was investigated as shown in Figure 2. pages 2, lines: 86-87: “…and cement-grouted sand with microstructures characterization is presented in Figures 5 and Figure 6.”. The study results should be reported in the section “ 3. Result and analysis”. In section “2. Materials and Methods" used materials, equipment and methodology should be described. Response: The types of equipment and the tests have been added to the paper.

1. „Figure 1. Flowchart methodology”: The flowchart should be described in the text. Response: The flowchart described has been added to the paper based on your suggestion.

1. The caption of figures 8; 9; 10; 11; 13 and 14 should be corrected. The description must explain what is shown in the figure a; b and c. Response: All the figure titles have been modified to explain what is shown in the figure

1. In the paper, there is no information on measurement errors and statistical analysis of results. This information should be included in the text. Response: The error information and the statistical analysis (R² and RMSE) have been described in the text.

7. The English needs careful editing. The editing services of a native English speaker could easily address this point. Response: The texts, including the abstract, tables, and figures, have been edited and organized in conversions, spelling, nouns, variety, word order, punctuations, preposition, and fluency, and the text language has been checked using the Grammarly editing program. The paper has been modified to satisfy the scientific journal requirements.

Reviewer 4 Report

A study of similar literature studies should be completed.

Conclusions can be supplemented with an indication of the advantage of the polymer used.

Author Response

Reviewer 4

Comments and Suggestions for Authors

A study of similar literature studies should be completed. Conclusions can be supplemented with an indication of the advantage of the polymer used. Response: Thanks for the observations made by reviewer #4; the whole paper, including the conclusions, has been modified.

Reviewer 5 Report

I reviewed the manuscript “Experimental and Modeling Evaluations to Predict the Flexural and Compressive Strengths of Cement-Based Grout Incorporated Polymers".

The authors in their publication showed the influence of the different sand grading on the compressive strength of cement grout treated with polymer using BS and ASTM standards. However, the article is missing a few things that are listed below:

The introduction section is well-referenced, and the main goals are well indicated, even if it appears a bit synthetic.
As concerns, the Materials and Methods section, in my opinion, it should be re-organized. In fact, there are lots of subsections, and this could induce the reader in error; moreover, after the 2.2.4 section there is the 2.7 section, what about the others in the middle?
As concerns, the 2.2.1 section, XRD, the authors should better describe the instrument used for the analyses, its settings, and the procedure for the sample preparation.
As regards figure 5 and 6, they should be more specifically described in the captions or in the text (2.2.2 section).
Also, the results section should be better organized, in fact, the authors should revise the editing of the text including a small results discussion in the paragraph.
In my opinion, the conclusions section is too much synthetic, considering that the authors do not include a discussion paragraph in their manuscript.
Lastly, the authors should implement the bibliography adding some more references.

In my opinion, this is a fairly good manuscript,  but it needs to be revised by the authors.

Author Response

Reviewer 5:

Comments and Suggestions for Authors

I reviewed the manuscript “Experimental and Modeling Evaluations to Predict the Flexural and Compressive Strengths of Cement-Based Grout Incorporated Polymers". The authors in their publication showed the influence of the different sand grading on the compressive strength of cement grout treated with polymer using BS and ASTM standards. However, the article is missing a few things that are listed below:

The introduction section is well-referenced, and the main goals are well indicated, even if it appears a bit synthetic. As concerns, the Materials and Methods section, in my opinion, it should be re-organized. Response: Thanks for the observations made by reviewer #5; the whole paper, including the introduction, methodology, tables, figures, and conclusions, have been modified, and the paper is stratified with the high journal requirements.

 

 

 In fact, there are lots of subsections, and this could induce the reader in error; moreover, after the 2.2.4 section there is the 2.7 section; what about the others in the middle? Response: The section numbers have been renumbered.

As concerns, the 2.2.1 section, XRD, the authors should better describe the instrument used for the analyses, its settings, and the procedure for the sample preparation. Response: The XRD section has been modified based on the reviewer's suggestions.

As regards figure 5 and 6, they should be more specifically described in the captions or in the text (2.2.2 section). Response: The SEM section has been modified based on the reviewer's suggestions.

Also, the results section should be better organized; in fact, the authors should revise the editing of the text, including a small results discussion in the paragraph. Response: The whole paper, including the introduction, methodology, tables, figures, results, and conclusions, have been modified.
In my opinion, the conclusions section is too much synthetic, considering that the authors do not include a discussion paragraph in their manuscript. Response: Thanks for the comment; the whole paper, including the conclusions, has been modified.

Lastly, the authors should implement the bibliography adding some more references. In my opinion, this is a fairly good manuscript,  but it needs to be revised by the authors. Response: The references as well have been organized and modified.

 

 

 

 

Round 2

Reviewer 2 Report

In the revised manuscript some improvements have been made in, but these are insufficient. The Authors only partially responded to the reviewer's comments, not always making appropriate corrections (contrary to their responses). Some comments were omitted. Some of the key information is still missing.

 

1. According to 1.The title is incorrect, it was spelled incorrectly - stylistic errors make it confusing and do not match to the paper content: - it is difficult to understand what the authors mean when they write "Experimental and Modeling Evaluations to Predict ...",- it was the polymer that was added to the grout, not the grout to the polymer.  Responses: The title has been modified based on the reviewer 2’s suggestion

Comment: The research subject are sands or grout?  - interpretation may vary depending on the read manuscript fragment. In the introduction, the Authors write about grouting used to close cracks in the rocks, not to sands grouted - be more precise.

 

2. According to 3. Abstract - it was incorrectly prepared, contrary to the "Instructions for Authors". Responses: The abstract has been modified based on your suggestion.

...

-l.20-25 the information from these two sentences is misleading. The Authors state twice that they achieve the highest strength - probably it is about testing various mortars, but this does not result from these sentences (due to an incorrect structure). Responses: Dear reviewer, the sentence has been modified based on the detailed response to the reviewers. Thanks.

...

Comment: Abstract has been significantly improved. Unfortunately, the sentences are confusing and make it difficult to understand the authors' ideas. Style should be improved. Additionally:

- l42. "Sec" is an invalid abbreviation,

 

3. According to 5. l.38-40 “To cover the sand particles, a high flowable CG is the main goal .” - this sentence is incomprehensible. Why is this the goal? The goal of what? A sentence taken out of context, because the cement substitute was previously described. Shouldn't it be combined with the following sentence: “As a result, the component's CS and bonding strengths will greatly enhance”? Or rather, the results described in this sentence relate to the use of cement substitutes?  Responses: the sentence has been modified based on your suggestion.

Comment: insufficient modification – the text is still inconsistent. What does "v" mean in l.76 ?

 

4. According to 7. I.42 "CM" - unexplained abbreviation (Cement Mortar?) Responses: it means cementitious materials, and it is explained in the text.

Comment: This is not explained in the text. The "cementitious materials" wording does not appear anywhere in the paper. The "CM" appears three times and is nowhere explained.

 

5. According to 7. l.41-44 I do not agree with the Authors' claim that water reducers (plasticizers and superplasticizers) used in the concrete technology shortened the setting time (often the opposite effect is true). The incorrectly cited references [6-8]; they do not concern the influence of admixtures on the properties of such materials at all.Responses: Agree with the comment, and the right references have been used in [6, 7, 8].

Comment: As for polymer influence on the setting time, items 7 and 8 are appropriate - but they contradict the authors' statement on shortening the setting time. According to [7] and [12], the polymers addition extended the setting time, rather than shortened it.

 

6. According to 10. l.50-53 The Authors should explain why the performance of the compressive strength test with two different methods is important - what is it supposed to prove? Why was the compressive strength tested with two methods and the flexural strength with only one method? It would also be necessary to explain why the given methods were chosen and, of course, provide which methods were chosen.

Response:

As it is known that the shape of the sample is affecting the compressive strength of the materials. And Since the BS standard uses prismatic mold (40 x 40 x 160 mm) and ASTM standard cylindrical mold (100 x 200 mm), the correlation between these two most common standards is needed. The cube is more stable in shape, and the strength will be higher than the cylinder. The broken pieces of the prism will exhibit higher strength than the cubes. The shape and size will govern the strength of broken pieces, as well as they would have gone through the test so that they may contain many micro cracks. Different shapes are subjected to different levels of influences due to eccentricity, lateral confinement, distribution of aggregates, and internal defects. Different countries/organizations have issued different standard testing methods to regulate the testing to evaluate the material with the same criterion and test method in that country/region. The test results of compressive strength are also dependent on the test specimen's dimension, referred to as the size effect. In nature, the size effect is also associated with the influence of eccentricity, lateral confinement, distribution of aggregates, internal defects, etc.

Compression loads are applied in the casting direction for the cylinder and perpendicular to the casting direction for the cubes. Because both cylinder and cubes are cast and consolidated in multiple layers, the direction of loading is essential in the relationship between cylinder strength and cube strength. When cylinders are loaded, each casting layer occupies an entire cross-section and receives the testing machine's total load. Each layer extends from top to bottom when cubes are loaded and gets a portion of the total load [1].

Compared with the cube test, the advantages of the cylinder are less end restraint and a more uniform distribution of stress over the cross-section; for these reasons, the cylinder strength is probably closer to the true uniaxial compressive strength of cement-based materials than the cube strength. According to all experimental data of the relation between cube and cylinder stated that the cylinder strength of hardened cement-based materials is not a constant value of 0.8 times the cube strength because it depends upon so many factors water-cement ratio, quality of sands (grading, surface texture, size, shape, strength, and stiffness), cement content and the period [2, 3, 4] below: 

1. Malaikah, A. S. (2005). Effect of specimen size and shape on the compressive strength of high strength concrete. Pertanika J. Sci. Technol, 13(1), 87-96.
2. Hamad, A. J. (2017). Size and shape effect of specimen on the compressive strength of HPLWFC reinforced with glass fibres. Journal of King Saud University-Engineering Sciences, 29(4), 373-380.
3. Kumari, R. (2015). Review paper based on the relation between the strength of concrete cubes and cylinders. International Journal of Engineering Research and Applications, 5(8), 52-54.
4. Elwell, D. J., & Fu, G. (1995). Compression testing of concrete: cylinders vs. cubes (No. FHWA/NY/SR-95/119).

Comment: The Authors gave a good explanation for the questions regarding the choice of compressive strength testing methods. I believe that it would be appropriate to include such an explanation in the text. I still think that the numbers of selected BS and ASTM standards should be specified here.

 

7. According to 11. l.65 Incorrectly selected references [10-12] - these items do not describe the polycarboxylate admixtures steric effects.Responses:Agree with the comment, and the right references have been used in [10, 11, 12].

Comment: In [10, 11] a different mechanism of superplasticizers effect is described - an electrostatic mechanism usually combined with sulphonic superplasticizers (e.g.  sulphonated naphthalene formaldehyde SNF) - a steric mechanism is typical for polycarboxylates (I recommend reading the work of Anatol Zingg). In [12] there is no description of the mechanism of superplasticizers effect .

 

8. l.89 "polymeric admixture surfaces"? it's probably a mistake.

 

9. According to 14. Figure 3 instead of "mineralogical composition," I recommend using "phase composition". How was the quantified phase composition determined? Based on the oxide composition or on the basis of the diffraction pattern? Responses: The phase composition of cement was determined by X-ray powder diffraction, petrographic examination, and electron microprobe analysis.

Comment: I consistently suggest using the  "phase composition" term also in the other parts of this paper, e.g. l.234. I would also ask for a more detailed explanation of how the quantitative phase composition was obtained (how it was calculated) - all the presented research methods allow obtaining relevant data independently of each other.

 

10. According to 16. Figure. 2 Phase identification on the presented diffraction patterns raises doubts: Responses: All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results.

- Figure 2a Brushit has a very intense peak of around 21 °2θ, not 19, while Cassiterite has a most intense peak of around 26.5 °2θ, not 23,  - Figure 2b Quartz was misidentified. The most intense quartz peaks should be around 26 and 21 °2θ. Due to the lack of the 26 °2θ peak, it can be concluded that quartz is not present in this sample. The peaks attributed to quartz are most likely derived from gypsum and portlandite (possibly caused by moisture in the cement). Also unidentified are the intense peaks in the diffraction pattern, e.g. the peak of brownmillerite around 33.8 °2θ. Responses: A similar results were found from previously published studies [ 8, 11]. Really appreciate your effort to improve the quality of this paper. All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results

 

Comment: The authors' explanation is insufficient and therefore I still think that the diffraction patterns interpretation is incorrect.

It is true that it cannot be ruled out that the Authors were dealing, for example, with a case of cement where quartz appeared in some unusual crystallographic form - but in such a case, appropriate crystallographic studies confirming such a thesis (theirs or other Authors) should be presented. Currently, referring to the ICDD data sheets:

Quartz - e.g. PDF# 00-005-0490; 00-33-1161or 00-046-1045

Brushite - e.g. PDF# 00-009-0077 or 01-072-0713

Cassiterite - e.g. PDF# 00-041-1445 or 01-071-5323

the Authors' interpretations may be considered  as incorrect. For the same reasons, the interpretations from the previous works of the Authors [8, 11] can also be considered as incorrect. In this paper, they also did not provide any source on the basis of which they "identified" quartz.

The authors' responses do not explain why they did not identify all the visible intense peaks on the diffraction patterns.

 

11. Section 2.1.3. Please describe the used sands in more detail. What is their (geological) origin?

 

12. According to 18. Section 2.2. Methods section was inappropriately prepared. There is no essential information on the performed tests, which prevents correct interpretation of the results. Thus, the section content is inconsistent with its title: Responses: The Methodology section has been justified and modified based on your suggestion.

- only the brief information on the performed XRD (2.2.1) and SEM (2.2.2) tests was provided, without information about the equipment used for the tests - XRD and incomplete data on SEM, sample preparation or measurement parameters. Responses: The Methodology section, including XRD and SEM tests, has been justified and modified based on your suggestion.

- in section 2.2., the methods of flexural and compressive strength tests, essential for this work, were not described at all. From the whole work it follows that they were carried out on the basis of some ASTM and BS standards, not precisely specified. There are also no specific standards in the references. Responses: The standards and the tests information have been added to the paper.

Comment:

- section 2.2.2. How were the test samples obtained (in what form)? Were the samples sputtered? What detector was used? What was the vacuum? - this information should be provided in the description.

Was there any reason for using such a high voltage and wide spot? - it diminished to some extent the quality of obtained images.

- l.259 "properties" - rather "microstructure"

-  WHICH SPECIFIC STANDARDS WERE  FOLLOWED IN COMPRESSION AND FLEXURAL STRENGTH TESTS?

- Were the  ASTM??? and BS??? samples cured under the same conditions? – in compliance with both standards, or according to a modified procedure?

 - l.404. wrong degree marking - instead of "o",  "°" should be used

 

12. According to 20. l.73 incorrect numbering of sections. After section 2.2. there is section 2.7. I believe that section 2.7 "Data analysis" should be placed as section 3. However, this section lacks the description and justification of the selected models - only equations are given, additional references to the literature are given for the non-linear model, but not for the linear model. Responses: All the section numbers have been corrected. Thanks

Comment: Contrary to the Authors claim, corrections have not been made, e.g., section 2.7. follows section 2.2.!

 

13. According to 21. l.164 [13] it is not the ASTM C 938 standard in the references.

 Responses: Agree with comments since the ASTM C 938 was used in the [13], that’s why the authors preferred to support the test with [13], which was the same test procedure was conducted

Comment: I understand the Authors position, but I believe that when referring to standards, it is always more correct and effective to refer directly to the original, not to the article where the method is only briefly mentioned. This prevents possible distortions and is more ethical. Moreover, a reader does not know immediately which version of the standard was used by the Authors.

For the same reason, I believe that the reference to ASTM 39 [13] in l.410 should be changed.

 

14. According to 23. 202-204 Did the Authors investigate the surface area to justify their statement? It is known that usually the finer material has a larger outer surface area than the coarser material. To explain the differences in fluidity, one can also pay attention to the aggregate particle shape and size. Responses: Surface area of the materials was not considered in this study.

Comment: In that case, I don't think the Authors should write about it because they don't have any evidence to support their thesis. As I wrote, it is easy to present the opposite thesis that fine aggregates have a larger specific surface, which can be proved by its geometry.

 

15. According to 24. l.208-210 premature conclusion. At this stage, it should not be said which grout is the best. The only thing that can be said is which grout have the best flow - which is obvious. Responses: I agree with the comment that the best grout is high flowable with high strength early.

Comment: text was left unchanged

 

16. According to 25. l.223-228 the content of the paragraph on the phase analysis is inconsistent with the section title. When writing chemical formulas, use a subscript for the digits. Responses: All chemical formulas have been checked in terms of writing. Thanks for the comments.

Comment: Incomplete answer. Phase analysis is not a microstructure study  - that's why my advice is to change the subsection title or divide it.

 

17. According to 30. l.274 "muscularly" - incorrect word. Responses: Fixed and Thanks.

Comment: this word,  even the correct, should not be used in this context.

 

18. According to 32 l.294 How do the Authors understand the concept of "typical flexural strength"? I notice that there are different polymeric admixtures - not just water reducers that can affect the grout properties differently. Responses: Agree with comment. The word “typical” means that only two curing age results have been presented in Fig. 13.

Comment: the text has not been properly modified to make it clear to readers - it can be misunderstood.

 

19. References - were prepared incorrectly, among others, due to: - the bibliographic data are provided in the way inconsistent with the guidelines in the "Instructions for Authors",- items [1] and [4] are the same item, only in [4] there are only the names of the Authors not presented in [1], Responses: Fixed and Thanks.

Comment: references formatting still does not fully follow to the "Instructions for Authors", e.g.:

- titles of journals should be given in abbreviated form,

- the year of publication should be given after the  journal name in bold,

- items [8] and [10] are the same item.

Author Response

Thank you very much for your time and efforts during reviewing our paper.
The modifications have been made based on the reviewer's comments and the last version of the paper is attached.

Reviewer 3 Report

The Authors responded to most of my questions. As it stands, the paper is much better and can be published.

Author Response

Thank you very much for your time and efforts during reviewing our paper.
The modifications have been made based on the reviewer's comments and the last version of the paper is attached.

Reviewer 5 Report

I would like to thank the authors for the revisioned version of the manuscript.
Anyway, I noticed that on pag.14 the authors pass from paragraph 2.2.6 to paragraph 2.7. I suppose they should correct the numeration of the paragraph in  2.3. (See the attached PDF file with highlighted parts at pag.14).

However, all the other changes previously suggested have been suitably addressed.

Comments for author File: Comments.pdf

Author Response

Thank you very much for your time and efforts during reviewing our paper.
The modifications have been made based on the reviewer's comments and the last version of the paper is attached.

Round 3

Reviewer 2 Report

The manuscript was not properly improved. Contrary to the accepted practice, the Authors sent only a revised version of the article without responding to the reviewer's comments  at all and did not make appropriate changes in the manuscript.

For example, they did not explain on what basis they performed the interpretation of the diffraction patterns - which is incorrect due to the incorrect peaks identification (comment 10 from the previous review).

This manuscript was also poorly prepared for the review - a lot of unnecessary formatting markings were introduced, often without explaining what was changed.

Author Response

Reviewer 1

Thank you very much for your manuscript. I have several comments as follows, and I hope that these can help improve your manuscript:

1. Repeated abbreviation for "compressive strength - CS" (line 20, line 21); Response: Fixed and Thanks.  
2. What does "CM" stand for? (line 42); Response: it means cementitious materials (CM). Provided and thanks.
3. It's necessary to have a definition of σ_c (line 56) and d₁₀ (line 57); Response:  Provided and thanks.
4. Reference No. [4] lacks of information (line 354); Response:  The ref. 4 has been changed.
5. "...behavior cement ..." (line 65) should be replaced by "...behavior of cement ..."; Response:  Corrected and thanks.
6. "PSD and Gs" (line 77, 78) needs to be expressed or explained; Response:  provided as you suggested.
7. What does "SEM" stand for? (line 83); Response:  Scanning Electron Microscopy (SEM). Provided based on your suggestion.
8. It would be better if Figures 5a and 5b have the same size. The same situation for Figures 6a and 6b; Response:  The figures are almost the same size thanks for your comments.
9. "Flowchart methodology" (line 128): I suggest that "Flowchart of methodology"; Response:  Done and thanks.
10. Figure 1 (page 3): lack of the connection between "ASTM standard" and "Cylindrical compressive strength"; abbreviation in advance or legends for "NLR" and "LR" are necessary; Response:  The connections are fixed, and the abbreviation is also provided. Thanks.
11. Table 2 (page 6): what is the unit of CS?; "Flow and CS ..." (line 169) should be replaced by "Flow time and CS..."; Response:  the units are provided, and “flow time and CS” is modified. Thanks.
12. "The flow cone method" (line 171): it would be better if a brief description of the method is shown here; Response:  more information about the flow cone test has been added to the paper.
13. "P" in equations 1 to 6, it is "Polymer" as I understood. However, there was no definition, note or legend of "P"; Response:  the  “P = polymer conten (%)” is added to the text.
14. "When fine-grained sand ... the w/c was increased." (line 197-198): this statement needs to be justified by data or at least more explanation; Response:  The whole paragraph has been modified and clarified based on your suggestion.
15. "The CG prepared ... was between 0.57 - 0.6," (line 199-201): I see that this statement is only true with w/c = 0.57 as described in Table 2. Please double check this; Response:  . In the case of a high water/cement ratio ranging between 0.57-0.6, the cement grout prepared with fine-grained sand (Sand # 2) found the highest compressive strength at 28 days compared to other mixes but in the lowest water/cement ratio ranged between 0.5-0.53 the coarse-grained sand obtained the highest compressive strength at 28-days of curing compared to the other mixes. The paragraph has been check it and modified.
16. "..., but the coarse-grained sand ... was between 0.5 - 0.53.": it 's better to mention in detail here with data and/or to indicate which "sand no." here; Response:   “ Sand #5” is added to the text.
17. "...; finer-grained sand produces a more homogeneous CG mixture than coarser-grained sand." (line 203-204): I think this is obviously true. I am not sure if this is the result of your research or it is just a statement in general; Response:    Yes it this study results. At a high water/cement ratio, the finer-grained sand leads to a more uniform cement grout mixture than coarser-grained sand due to the smaller surface area of the finer-grained sand relative to that of the coarser-grained sand.
18. "..., adding polymers reduced the water content of CG by 20% to 54% to achieve the necessary flowability, as shown in Figure 7. Depending on the types of sand and the flow period, adding the 0.12 % polymer reduced the w/c of CG by 23 to 50 per-cent." (line 215 - 218): please justified by data or more explaination; ; Response:    more explanation is added to the text.
19. What does "PC" stand for? (line 229); Response:    PC= Portland cement.
20. To have a better visual comparison, Figure 9a and 9b (page 10) should be displayed as the same scale. Response: I agree with the comment. And it is fixed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reviewer 2

 

Comments and Suggestions for Authors

The reviewed manuscript presents the various methods comparison of testing the strength of grouts with polymer admixture and aggregate with different particle size using. This comparison also included the fit of individual test methods to different mathematical models. Unfortunately, the quality of this paper should be assessed as very low. First of all, despite the fact that the Ators compared research methods, they did not describe them (comment 18). It is not known how and on what samples the tests were carried out. The results of these studies have been discussed very briefly without accurate analysis. In the case of the XRD analysis, it was misinterpreted. Response: The whole paper, including the text with the explanations of the test, has been modified and explained to be clear for the readers. After responding to the reviewer comments, the paper is satisfied with the high-quality journals.

The article was also written in incorrect English, which additionally hinders its understanding (some language errors examples will be presented in the later part of review).

Responses: Thanks for the comment, The texts, including the abstract, tables, and figures, have been edited and organized in terms of discussions, conversions, spelling, nouns, variety, word order, punctuations, prepositions, and fluency. The paper has been modified to satisfy the scientific journal requirements, more functional models have been added to justify the results.
 Below is a detailed list of comments:

 1.The title is incorrect, it was spelled incorrectly - stylistic errors make it confusing and do not match to the paper content: - it is difficult to understand what the authors mean when they write "Experimental and Modeling Evaluations to Predict ...",- it was the polymer that was added to the grout, not the grout to the polymer.  Responses: The title has been modified based on the reviewer 2’s suggestion

2. Provide full Authors affiliation details - addresses are missing:  Responses: Correct affiliations have been added. Thanks.
3. Abstract - it was incorrectly prepared, contrary to the "Instructions for Authors". Responses: The abstract has been modified based on your suggestion.

- the aim of article was presented too briefly. Responses: The aim of the study has been modified based on your suggestion.

- the test methods were not presented clearly - only the compressive strength test was mentioned. Information about flexural strength tests included in the article title are mentioned only in the last sentence. There was no mention about the flow test or SEM. Responses: The test methods of the study have been modified and highlighted in the text. Thanks for the time and effort.

- specify which polymers were the research subject, Responses: The Polycarboxylate ether-based polymer was used in this study, consisting of one main linear backbone with side carboxylate groups. The groups of carboxylates are the anchoring groups by which these admixtures are added to modify the cement. The solid content of Polycarboxylate ether-based polymer with a pH of 10  is greater than 97%.

- l.20-25 the information from these two sentences is misleading. The Authors state twice that they achieve the highest strength - probably it is about testing various mortars, but this does not result from these sentences (due to an incorrect structure). Responses: Dear reviewer, the sentence has been modified based on the detailed response to the reviewers. Thanks.

- l.21 do not need to explain the "CS" abbreviation for the  second time. Responses: The CS is compressive strength, and the abbreviation has been added to the paper. Thanks.

4. Keywords - are too general, e.g. sand, strengths. I suggest adding: cement grout.

 Responses: Thanks for the suggestion. It is added.

5. l.38-40 “To cover the sand particles, a high flowable CG is the main goal .” - this sentence is incomprehensible. Why is this the goal? The goal of what? A sentence taken out of context, because the cement substitute was previously described. Shouldn't it be combined with the following sentence: “As a result, the component's CS and bonding strengths will greatly enhance”? Or rather, the results described in this sentence relate to the use of cement substitutes?  Responses: the sentence has been modified based on your suggestion.
6. l.40 "creation" - change the word. Responses: Sure, and it is done.
7. I.42 "CM" - unexplained abbreviation (Cement Mortar?) Responses: it means cementitious materials, and it is explained in the text.
8. l.41-44 I do not agree with the Authors' claim that water reducers (plasticizers and superplasticizers) used in the concrete technology shortened the setting time (often the opposite effect is true). The incorrectly cited references [6-8]; they do not concern the influence of admixtures on the properties of such materials at all. Responses: Agree with the comment, and the right references have been used in [6, 7, 8].
9. l.45 "When a CM was prepared with coarser sand grading than fine sand" - it is obvious that coarse sand has coarser graining than fine sand, so I see no reason to write "..than fine sand". Responses: Removed as you suggested.

 

10. l.50-53 The Authors should explain why the performance of the compressive strength test with two different methods is important - what is it supposed to prove? Why was the compressive strength tested with two methods and the flexural strength with only one method? It would also be necessary to explain why the given methods were chosen and, of course, provide which methods were chosen.

Response:

As it is known that the shape of the sample is affecting the compressive strength of the materials. And Since the BS standard uses prismatic mold (40 x 40 x 160 mm) and ASTM standard cylindrical mold (100 x 200 mm), the correlation between these two most common standards is needed. The cube is more stable in shape, and the strength will be higher than the cylinder. The broken pieces of the prism will exhibit higher strength than the cubes. The shape and size will govern the strength of broken pieces, as well as they would have gone through the test so that they may contain many micro cracks. Different shapes are subjected to different levels of influences due to eccentricity, lateral confinement, distribution of aggregates, and internal defects. Different countries/organizations have issued different standard testing methods to regulate the testing to evaluate the material with the same criterion and test method in that country/region. The test results of compressive strength are also dependent on the test specimen's dimension, referred to as the size effect. In nature, the size effect is also associated with the influence of eccentricity, lateral confinement, distribution of aggregates, internal defects, etc.

Compression loads are applied in the casting direction for the cylinder and perpendicular to the casting direction for the cubes. Because both cylinder and cubes are cast and consolidated in multiple layers, the direction of loading is essential in the relationship between cylinder strength and cube strength. When cylinders are loaded, each casting layer occupies an entire cross-section and receives the testing machine's total load. Each layer extends from top to bottom when cubes are loaded and gets a portion of the total load [1].

Compared with the cube test, the advantages of the cylinder are less end restraint and a more uniform distribution of stress over the cross-section; for these reasons, the cylinder strength is probably closer to the true uniaxial compressive strength of cement-based materials than the cube strength. According to all experimental data of the relation between cube and cylinder stated that the cylinder strength of hardened cement-based materials is not a constant value of 0.8 times the cube strength because it depends upon so many factors water-cement ratio, quality of sands (grading, surface texture, size, shape, strength, and stiffness), cement content and the period [2, 3, 4] below: 

1. Malaikah, A. S. (2005). Effect of specimen size and shape on the compressive strength of high strength concrete. Pertanika J. Sci. Technol, 13(1), 87-96.
2. Hamad, A. J. (2017). Size and shape effect of specimen on the compressive strength of HPLWFC reinforced with glass fibres. Journal of King Saud University-Engineering Sciences, 29(4), 373-380.
3. Kumari, R. (2015). Review paper based on the relation between the strength of concrete cubes and cylinders. International Journal of Engineering Research and Applications, 5(8), 52-54.
4. Elwell, D. J., & Fu, G. (1995). Compression testing of concrete: cylinders vs. cubes (No. FHWA/NY/SR-95/119).
5. l.65 Incorrectly selected references [10-12] - these items do not describe the polycarboxylate admixtures steric effects. Responses: Agree with the comment, and the right references have been used in [10, 11, 12].
6. l.65-66 please explain the relation between polymer pH and solids content. What is the significance of this for the performed tests and how was it determined. Responses: data were provided from the supplier, and the authors did not do the tests.
7. Figure 1 is not described in the text - The Authors do not explain what it presents. Responses: The detailed explanation for Fig. 1 has been added to the paper based on your suggestion.
8. Figure 3 instead of "mineralogical composition," I recommend using "phase composition". How was the quantified phase composition determined? Based on the oxide composition or on the basis of the diffraction pattern? Responses: The phase composition of cement was determined by X-ray powder diffraction, petrographic examination, and electron microprobe analysis.
9. l73-74 Information about used polymer should be included in the appropriate section (2.1.1.), not in the cement description (2.1.2.). Due to the diversity of materials and the specificity of the XRD tests performed, the information about the peak intensities in different materials is not important. Responses: The sections and the polymer information have been explained and modified based on the reviewer's comments.
10. Figure. 2 Phase identification on the presented diffraction patterns raises doubts: Responses: All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results.

 

 

 

 

- Figure 2a Brushit has a very intense peak of around 21 °2θ, not 19, while Cassiterite has a most intense peak of around 26.5 °2θ, not 23,  - Figure 2b Quartz was misidentified. The most intense quartz peaks should be around 26 and 21 °2θ. Due to the lack of the 26 °2θ peak, it can be concluded that quartz is not present in this sample. The peaks attributed to quartz are most likely derived from gypsum and portlandite (possibly caused by moisture in the cement). Also unidentified are the intense peaks in the diffraction pattern, e.g. the peak of brownmillerite around 33.8 °2θ. Responses: A similar results were found from previously published studies [ 8, 11]. Really appreciate your effort to improve the quality of this paper. All the tests in this study, including XRD and SEM tests, were conducted more than once to justify the results.

17. l.77-78 explain the "Gs" and "PSD" signs. Responses: The symbols have been explained.
18. Section 2.2. Methods section was inappropriately prepared. There is no essential information on the performed tests, which prevents correct interpretation of the results. Thus, the section content is inconsistent with its title: Responses: The Methodology section has been justified and modified based on your suggestion.

- only the brief information on the performed XRD (2.2.1) and SEM (2.2.2) tests was provided, without information about the equipment used for the tests - XRD and incomplete data on SEM, sample preparation or measurement parameters. Responses: The Methodology section, including XRD and SEM tests, has been justified and modified based on your suggestion.

- in section 2.2., the methods of flexural and compressive strength tests, essential for this work, were not described at all. From the whole work it follows that they were carried out on the basis of some ASTM and BS standards, not precisely specified. There are also no specific standards in the references. Responses: The standards and the tests information have been added to the paper.

19. Table 2. Move to section 3. The results discussed in later sections should not be given here. Responses: Done as you suggested. Thanks
20. l.73 incorrect numbering of sections. After section 2.2. there is section 2.7. I believe that section 2.7 "Data analysis" should be placed as section 3. However, this section lacks the description and justification of the selected models - only equations are given, additional references to the literature are given for the non-linear model, but not for the linear model. Responses: All the section numbers have been corrected. Thanks

 

 

 

21. l.164 [13] it is not the ASTM C 938 standard in the references.

 Responses: Agree with comments since the ASTM C 938 was used in the [13], that’s why the authors preferred to support the test with [13], which was the same test procedure was conducted.

22. Section 3.1. the description of the w/c-sand graining-flow relationship is incomprehensible (it was poorly formulated or translated): Responses: The information in the section has been modified. Thanks

- l.198 how was fine sand used to "achieve equal flowability"? What do the Authors mean by "equal flowability"? Responses: After modifying the sentence, the whole section was also modified

- l.199 w/c did not increase (incorrect term), because the Authors assumed that four constant levels of w/c were studied. Responses:  Based on your comments, most of the sentences have been modified, and thanks for your valid comments.

23. l.202-204 Did the Authors investigate the surface area to justify their statement? It is known that usually the finer material has a larger outer surface area than the coarser material. To explain the differences in fluidity, one can also pay attention to the aggregate particle shape and size. Responses: Surafe area of the materials was not considered in this study.
24. l.208-210 premature conclusion. At this stage, it should not be said which grout is the best. The only thing that can be said is which grout have the best flow - which is obvious. Responses: I agree with the comment that the best grout is high flowable with high strength early.
25. l.223-228 the content of the paragraph on the phase analysis is inconsistent with the section title. When writing chemical formulas, use a subscript for the digits. Responses: All chemical formuls have been checked in terms of writing. Thanks for the comments.
26. Figure 5 and 6 should be transferred from section 2.2.2. to 3.3. All figures and tables should be placed in the section in which they are discussed. . Responses: Done based on your suggestion.
27. Figure 9b is not described in the text. Responses: Fig. 9b added to the text.
28. Section 3.4.2. I think the description is too superficial. Responses: The section has been modified based on your suggestion.
29. Figure 11 - errors in the parentheses in the Y axis description. Responses: Fixed and Thanks.
30. l.274 "muscularly" - incorrect word. Responses: Fixed and Thanks.
31. l.289 "cube"? In l.25 only the study of prismatic and cylindrical samples was mentioned. Responses: Fixed and Thanks.
32. l.294 How do the Authors understand the concept of "typical flexural strength"? I notice that there are different polymeric admixtures - not just water reducers that can affect the grout properties differently. Responses: Agree with comment. The word “typical” means that only two curing age results have been presented in Fig. 13.
33. The article lacks a detailed results discussion in the light of contemporary literature. Section 3 presents only the results without accurate analysis. Responses: After responding to the reviewer comments, especially reviewer #2, the paper is stratified the high-level journal. Thanks for your time and efforts.
34. l.323 the term "electronic microscopy" is incorrect - it may be "electron microscopy" Responses: Fixed and Thanks.
35. References - were prepared incorrectly, among others, due to: - the bibliographic data are provided in the way inconsistent with the guidelines in the "Instructions for Authors",- items [1] and [4] are the same item, only in [4] there are only the names of the Authors not presented in [1], Responses: Fixed and Thanks.

from comments 8 and 11, it follows that the literature was not properly selected. Responses: Fixed and Thanks.

36. There are various spelling mistakes in the paper, incorrect vocabulary (e.g., comments 6, 30 and 34), sentence structure, or incorrect spacing (e.g., l.217, 288, 299). Responses: Thanks for the comment, The texts, including the abstract, tables, and figures, have been edited and organized in terms of discussions, conversions, spelling, nouns, variety, word order, punctuations, prepositions, and fluency.

 

 

 

 

 

 

 

 

 

Reviewer 3

The paper presents and discusses interesting data about mechanical properties of cement grout with the addition of polymer. The research results presented in the article may be of interest to people involved in civil engineering. Unfortunately the paper is not well presented. I tried on several occasions to read it and gave up as I simply became lost in the text. I am convinced that the work should not be published in its current form. In my opinion, it would be the best to rewrite the article again. The corrected work should be reviewed again. Hereafter are my main comments: Response: Thanks for the time and efforts spent in the reviewing process. The paper, including text, figures, and tables, has been modified based on the reviewer's comments. After the modification, the paper is satisfied the journal readers.

1. When a symbol or abbreviation first appears in the text, it must be explained (examples of unexplained symbols: CM (line 42), sf (line 45), sc (line 56), d10 (line 57) and many other! It would also be helpful to add a list of symbols. Response: CM means cementitious materials. Most of the simples in the text have been identified and highlighted in the paper.

1. Page 2, lines 63-64: “In this study, a water reducer polymer with one linear backbone consists of side groups of carboxylate.” Please provide the polymer name that was used in the tests.  Response: The name of the polymer is added to the text.

1. Page 2, lines 68-69: “Figure 2 (a) shows the Xray Diffraction (XRD) test results on the cement and polymer which are utilized in this research. Response: Modified, and thanks.

 page 2, lines 71-75: “Figure 2(b) shows XRD test of OPC. Response: Modified, and thanks.

Figure 3 shows the mineralogical and chemical compositions of the cement. The peak intensity of the water reducer polymer is between 1500 and 2000, according to Figure 2 (a), but the peak intensity of the cement is about 300, as shown in Figure 2(b). Response: Modified, and thanks.

page 2, lines 77-78: “In this research, five sand with different grading were used. Figure 4 shows the PSD and Gs of the sands utilized, which are also shown in Table 1. Response: Modified, and thanks.

Page 2, lines 81-82: “At a temperature of 25°C, the chemical composition of water reducer polymer and cement was investigated as shown in Figure 2. pages 2, lines: 86-87: “…and cement-grouted sand with microstructures characterization is presented in Figures 5 and Figure 6.”. The study results should be reported in the section “ 3. Result and analysis”. In section “2. Materials and Methods" used materials, equipment and methodology should be described. Response: The types of equipment and the tests have been added to the paper.

1. „Figure 1. Flowchart methodology”: The flowchart should be described in the text. Response: The flowchart described has been added to the paper based on your suggestion.

1. The caption of figures 8; 9; 10; 11; 13 and 14 should be corrected. The description must explain what is shown in the figure a; b and c. Response: All the figure titles have been modified to explain what is shown in the figure

1. In the paper, there is no information on measurement errors and statistical analysis of results. This information should be included in the text. Response: The error information and the statistical analysis (R² and RMSE) have been described in the text.

7. The English needs careful editing. The editing services of a native English speaker could easily address this point. Response: The texts, including the abstract, tables, and figures, have been edited and organized in conversions, spelling, nouns, variety, word order, punctuations, preposition, and fluency, and the text language has been checked using the Grammarly editing program. The paper has been modified to satisfy the scientific journal requirements.

 

Reviewer 4

Comments and Suggestions for Authors

A study of similar literature studies should be completed. Conclusions can be supplemented with an indication of the advantage of the polymer used. Response: Thanks for the observations made by reviewer #4; the whole paper, including the conclusions, has been modified.

Reviewer 5:

Comments and Suggestions for Authors

I reviewed the manuscript “Experimental and Modeling Evaluations to Predict the Flexural and Compressive Strengths of Cement-Based Grout Incorporated Polymers". The authors in their publication showed the influence of the different sand grading on the compressive strength of cement grout treated with polymer using BS and ASTM standards. However, the article is missing a few things that are listed below:

The introduction section is well-referenced, and the main goals are well indicated, even if it appears a bit synthetic. As concerns, the Materials and Methods section, in my opinion, it should be re-organized. Response: Thanks for the observations made by reviewer #5; the whole paper, including the introduction, methodology, tables, figures, and conclusions, have been modified, and the paper is stratified with the high journal requirements.

 

 

 In fact, there are lots of subsections, and this could induce the reader in error; moreover, after the 2.2.4 section there is the 2.7 section; what about the others in the middle? Response: The section numbers have been renumbered.

As concerns, the 2.2.1 section, XRD, the authors should better describe the instrument used for the analyses, its settings, and the procedure for the sample preparation. Response: The XRD section has been modified based on the reviewer's suggestions.

As regards figure 5 and 6, they should be more specifically described in the captions or in the text (2.2.2 section). Response: The SEM section has been modified based on the reviewer's suggestions.

Also, the results section should be better organized; in fact, the authors should revise the editing of the text, including a small results discussion in the paragraph. Response: The whole paper, including the introduction, methodology, tables, figures, results, and conclusions, have been modified.
In my opinion, the conclusions section is too much synthetic, considering that the authors do not include a discussion paragraph in their manuscript. Response: Thanks for the comment; the whole paper, including the conclusions, has been modified.

Lastly, the authors should implement the bibliography adding some more references. In my opinion, this is a fairly good manuscript,  but it needs to be revised by the authors. Response: The references as well have been organized and modified.