Experimental Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines
Round 1
Reviewer 1 Report
Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines
The manuscript examines the perceptual stress characteristics of functional cemented backfilling materials (CBM) in coal mines. The authors used functional specimens based on traditional CMBs with the perceptual stress ability, and clarified their conductive and perceptual mechanisms, and possible engineering applications. By using mechanical tests and network parallel dynamic method, the authors analysed the mechanical and electrical properties of the prepared materials and the perceptual characteristics under mechanical-electric coupling conditions. Taking under consideration the presentation of the manuscript as a whole it is clear that an interesting research work has been done.
However, a concern with the manuscript is that the experimental procedures are not explained in relation to theoretical analysis. In addition, the research questions as well as the original contribution of the work, comparing to other previous works could be better presented.
The authors should place more emphasis on (a) the research questions, (b) the explanation of the experimental procedures in relation to the theoretical analysis and (c) the original approach to the analysis of the problem.
Additional comments and recommendations for the improvement of the manuscript:
General note
Ø Please leave a space between numerical values and unit symbols
Title
The title of the manuscript could be improved.
Abstract
[Line 16] “…Cemented Backfilling Materials (CBM)…” instead of “…cemented backfilling materials (CBM)…”.
[Lines 20-22] “Test results demonstrate … simultaneously enhance the electrical ones”. This sentence is not clear and it should be improved.
1. Introduction
[Lines 38-40] “Thus, Fall et al. [1] examined the effect of curing temperature on the compressive strength of CBM and observed the related micro-structural changes” instead of “Thus, Fall et al. examined the effect of curing temperature on the compressive strength of CBM and observed the related micro-structural changes [1]”.
[Line 40] “Ouattara et al. [2] focused” instead of “Ouattara et al. focused” etc.
[Lines 50-52] “Scholars have achieved numerous promising results in the CBM stress measurements and monitoring but mostly neglected the issues of their functionality”. References are required here.
[Lines 74-82] This paragraph could be moved in the conclusions.
[Lines 75-76] “…into Functional ones (FCBM)” instead of “…into functional ones (FCBM)”.
2. Experimental
General note: The experimental procedures which are described in this paragraph could be presented in a flow chart.
[Fig. 2] Legend: Units are missing.
[Line 105] “…in Figure 3 [18]” instead of “…in Figure 3[18]”.
[Line 127] “Figure 4 illustrates the percolation theory in detail”. A further analysis is required here.
[Fig. 4] A reference is needed here.
[Eq. 4] E’ should be explained within the manuscript.
[Fig. 5] This figure should be improved. The axes labels are not clear.
[Fig. 6] Illustration of specific application design of “FCBM” or “CBM”?
3. Results and Discussion
[Lines 173-174] “…with different contents of the conductive phase…”. This sentence should be further explained.
[Fig. 7] Legend: Label is missing.
“Strength/MPa”. Is this correct?
[Lines 202-203] “…the classical percolation formula…”. A further explanation is needed here.
[Fig. 10] Legends: Labels are missing.
[Figs 11-13] Same comment as in Fig. 10.
[Lines 289-269] “The guidelines for practical engineering” can be numbered.
4. Conclusions
General note:
In this section, the original contribution of the research has to be presented by focusing on the research results based on the research questions.
References
[5] “…Acta Mater Compos Sin. 2019, 36…”. Is this correct?
Author Response
Dear editor and reviewers,
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript. We are grateful to the editor and reviewers for their positive and constructive comments and suggestions on our manuscript entitled “Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines” (Minerals-405877). These comments have all been of great help to us in the revision and improvement of our paper, as well as providing significant guidance for our research.
We have revised our manuscript according to the comments from the reviewers. We hope that the manuscript now meets with your approval. The main corrections to the paper and our responses to the reviewers are as follows:
General Comments: Taking under consideration the presentation of the manuscript as a whole it is clear that an interesting research work has been done. However, a concern with the manuscript is that the experimental procedures are not explained in relation to theoretical analysis. In addition, the research questions as well as the original contribution of the work, comparing to other previous works could be better presented. The authors should place more emphasis on (a) the research questions, (b) the explanation of the experimental procedures in relation to the theoretical analysis and (c) the original approach to the analysis of the problem.
Response: Thank you for your positive comments. These comments have all been of great help to us in the revision and improvement of our paper. We have studied your comments carefully and have tried our best to revise our manuscript according to the comments. I added theoretical analysis to explain the experimental process and changed the presentation way according to your suggestions.
Comments No. 1: The title of the manuscript could be improved.
Response: Thank you for pointing this out. The title of the paper had been revised: Experimental Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines
Comments No. 2:
(1) Please leave a space between numerical values and unit symbols.
(2) [Line 16] “…Cemented Backfilling Materials (CBM)…” instead of “…cemented backfilling materials (CBM)…”
(3) [Lines 38-40] “Thus, Fall et al. [1] examined the effect of curing temperature on the compressive strength of CBM and observed the related micro-structural changes” instead of “Thus, Fall et al. examined the effect of curing temperature on the compressive strength of CBM and observed the related micro-structural changes [1]”.
(4) [Line 40] “Ouattara et al. [2] focused” instead of “Ouattara et al. focused” etc.
(5) [Lines 50-52] “Scholars have achieved numerous promising results in the CBM stress measurements and monitoring but mostly neglected the issues of their functionality”. References are required here.
(6) [Lines 74-82] This paragraph could be moved in the conclusions.
(7) [Lines 75-76] “…into Functional ones (FCBM)” instead of “…into functional ones (FCBM)”.
(8) [Fig. 2] Legend: Units are missing.
(9) [Line 105] “…in Figure 3 [18]” instead of “…in Figure 3[18]”.
(10) [Fig. 4] A reference is needed here.
(11) [Eq. 4] E’ should be explained within the manuscript.
(12) [Fig. 5] This figure should be improved. The axes labels are not clear.
(13) [Fig. 6] Illustration of specific application design of “FCBM” or “CBM”?
(14) [Fig. 7] Legend: Label is missing.“Strength/MPa”. Is this correct?
(15) [Fig. 10] Legends: Labels are missing.
(16) [Figs 11-13] Same comment as in Fig. 10.
(17) [Lines 289-269] “The guidelines for practical engineering” can be numbered.
(18) [5] “…Acta Mater Compos Sin. 2019, 36…”. Is this correct?
Response: Thank you for pointing this out. I had modified the above problems according to your comments.
Comments No. 3:
(3) [Lines 20-22] “Test results demonstrate … simultaneously enhance the electrical ones”. This sentence is not clear and it should be improved.
Response: Thank you for pointing this out. I had modified the problems according to your comments. Test results demonstrate that the deformation of CBMs obey standard stress-strain rules, while the conductive phase addition can deteriorate their mechanical properties and simultaneously enhance the electrical conductivity of materials.
Comments No. 4:
(1) General note: The experimental procedures which are described in this paragraph could be presented in a flow chart.
Response: Thank you for pointing this out. I had added flow charts.
Comments No. 5:
(1) [Line 127] “Figure 4 illustrates the percolation theory in detail”. A further analysis is required here.
Response: Thank you for pointing this out. I had modified the problems according to your Suggestions. Illustrates the percolation theory in detail, The electrical conductivity of the material is discontinuous in the range of certain concentration of conductive filler, and the resistivity of the material will mutate at a certain temperature, which indicates that the dispersion of conductive particles in the polymer matrix has a sudden change at this time. When the concentration of the conductive phase reaches the percolation threshold, conductive paths are formed; then, electrodes move along the conductive paths, and the material turns from a high insulator into a conductor.
Comments No. 6:
(1) [Lines 173-174] “…with different contents of the conductive phase…”. This sentence should be further explained.
Response: Thank you for pointing this out. I had modified the problems according to your Suggestions. Firstly, uniaxial compressive tests were performed on the specimens with different amounts of the conductive phases to obtain the influence curve of conductive phase (graphite) content on mechanical properties of materials, as is shown in figure 9.
Comments No. 7:
(1) [Lines 202-203] “…the classical percolation formula…”. A further explanation is needed here.
Response: Thank you for pointing this out. I had modified the problems according to your Suggestions. The classical percolation formula: ρ=ρ0(m-mc)t, Where, ρ represents the conductivity of the conductive composite material, ρ0 is related to the material itself, m represents the mass fraction of the filler, mc represents the percolation threshold, and t represents the critical index related to the structure of the conductive network. and According to the classical percolation formula, fitted percolation threshold of the functional cemented filing material .
Comments No. 8:
(1) In this section, the original contribution of the research has to be presented by focusing on the research results based on the research questions.
Response: Thank you for pointing this out. We had added: Based on previous findings, this study selected graphite as the conductive phase for exploring the possibility of modifying traditional CBM into Functional ones (FCBM). Besides, the electrical sensing method was adopted for the first time in the geophysical field so as to assess the spatial distribution patterns of material resistivity, in order to overcome the deficiency of traditional two- or four-electrode schemes that fail to derive the spatial resistivity distribution characteristics in the specimen. Furthermore, the spatial distribution rules of the apparent resistivity of FCBM with different graphite contents under no stress and the related variation rules under mechanical-electrical coupled action were revealed, which can provide a theoretical basis for further investigations of FCBM.
Author Response File: 
Author Response.docx
Reviewer 2 Report
I think it is important to provide the granulometric analysis and the mineralogical composition of the gangue and the flying ash.
Figure 9 shows linear interpolation for only three points that has little statistical significance
clearly indicate the positive effects of the method (the good monitoring of the CBM) and the negative ones (the loss of resistance due to the graphite effect)
Author Response
Dear editor and reviewers,
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript. We are grateful to the editor and reviewers for their positive and constructive comments and suggestions on our manuscript entitled “Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines” (Minerals-405877). These comments have all been of great help to us in the revision and improvement of our paper, as well as providing significant guidance for our research.
We have revised our manuscript according to the comments from the reviewers. We hope that the manuscript now meets with your approval. The main corrections to the paper and our responses to the reviewers are as follows:
Comments No. 1:
(1)I think it is important to provide the granulometric analysis and the mineralogical composition of the gangue and the flying ash.
Response: Thank you for pointing this out. We have added data and pictures.
Table lists the main chemical ingredients of fly ash and gangue, It can be seen that the main ingredients of fly ash are SiO2 and Al2O3, which together determine the activity of fly ash. The main ingredients of gangue are SiO2 and Al2O3, and SiO2 is the main aggregate ingredient of CFM, which determines the strength of CFM under certain conditions.
According to the particle size test, the gangue particle size was within the range of 0-20 mm, which meets the requirements of cementing backfilling for aggregate particle size. The median particle size (50%) of gangue was 7.16 mm, and the cumulative through particle size of 80% was 9.98 mm. Fly ash particle size was within the range of 0-440 um, and the fly ash particle size was mainly concentrated in the range of 0-44 um (61.03%).
Comments No. 2:
(2)Figure 9 shows linear interpolation for only three points that has little statistical significance, clearly indicate the positive effects of the method (the good monitoring of the CBM) and the negative ones (the loss of resistance due to the graphite effect).
Response: Thank you for pointing this out. We had increased the corresponding data by 10%, and the percolation threshold is 9.85%, which is not much different from the previous data. We believe that there is still a lot of scientific research to be done on the positive and negative effects of materials in order to conclude that.
Please refer to the attachment for data and pictures.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
In the revised edition, the manuscript has been significantly improved and covered the comments of the reviewers.
Author Response
Dear editor and reviewers,
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript. We are grateful to the editor and reviewers for their comments on our manuscript entitled “Experimental Investigation of Perceptual Characteristics of Functional Cemented Backfilling Materials in Coal Mines” (Minerals-405877). These comments have all been of great help to us in the revision and improvement of our paper, as well as providing significant guidance for our research.
We have revised our manuscript according to the comments from the reviewers. We hope that the manuscript now meets with your approval. The main corrections to the paper and our responses to the reviewers are as follows:
Response to Reviewer 1 Comments
Point 1: It is recommended to include a few of the papers about CPB that is published in the special issue in the literature review. The following papers are given as examples:
Application of Slag–Cement and Fly Ash for Strength Development in Cemented Paste Backfills. Minerals 2019, 9(1), 22; https://doi.org/10.3390/min9010022
Effects of Superplasticizer on the Hydration, Consistency, and Strength Development of Cemented Paste Backfill. Minerals 2018, 8(9), 381; https://doi.org/10.3390/min8090381.
Response 1: Thank you for your positive comments. We had added: Zhao et al. [13] studied investigates the combined capacity of a newly developed slag-blended cement and fly ash as a sustainable solution towards improving the mechanical performance of the cemented paste backfill (CPB) system of a copper-gold underground mine. Zhang et al. [14] presented the fluidity and strength evolution of CPB containing the different dosages of polynaphtalene sulfonate and the physicochemical mechanism of the polynaphtalene sulfonate on the fluidity and strength evolution of CPB was investigated.
Author Response File: Author Response.docx
