Studying the Incorporation of Multi-Walled Carbon Nanotubes in High-Performance Concrete

Round 1

Reviewer 1 Report

This study investigates the influence of MWCNT on UHPC properties. While it covers an important topic, significant improvements are required. The author should focus more on explanation of the observed properties, especially from the structural point of view. The following should be corrected:

1. Lines 164-166 are unnecessary. 

2. Figures 4 and 5 are unnecessary, should be moved to supplementary or deleted.

3. FTIR must be included to show interactions between cement-plasticizer-MWCNT

4. Connect all of the properties with morphological and structural changes

5. Have you found a better way to disperse MWCNT? This would we a valuable information. How do you propose to expand this research?

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript.

The authors fully incorporate the comments of the Reviewers. The authors have addressed reviewer queries/comments as outlined in Tables 1, 2, 3, 4, and 5, as presented below.

I would very much appreciate it if this work could be considered for publication in your respected Journal.

Author Response File: Author Response.docx

Reviewer 2 Report

The article is well designed with a good piece of work. But the authors need to address the following point to improve the quality of the article.

·         Authors have used both forms of spelling “fiber” and “fibre”. It is advised to use any one form. Check the entire manuscript.

·         Page 1 Line -18 “at ration of 0, 0.2, 0.4 and 0.6% w/w” correct the spelling of ratio.

·         Abstract needs to be improved significantly. Add some quantitative data (results).

·         Page 4 Line -164 “Here includes all the experience performed in the laboratory” Is it experience or experiments?

·         Cross-check the unit of “Specific surface area”.

·         “The mechanical strength of each UHPCs serie produced was assessed in three prismatic specimens (40×40×160 mm3) and according the procedure of EN 196-1.” Rewrite this sentence. Very hard to understand.

·         In Figures 8 and 9. Change 0,2% to 0.2%. Else reader may get confused.

·         In Figure 10, what do you mean by MWCNVT?

·         Mark the point of observation in the SEM images. Also, correlate the SEM images with the obtained results.

·         Kindly reconcile the conclusion with the study objectives.

·         What are the practical implications of this study and the future directions? kindly state?

·         The article must undergo language proofreading, as I found grammatical and typo errors.

   The article must undergo language proofreading, as I found grammatical and typo errors.

 

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript.

The authors fully incorporate the comments of the Reviewers. The authors have addressed reviewer queries/comments as outlined in Tables 1, 2, 3, 4, and 5, as presented below.

I would very much appreciate it if this work could be considered for publication in your respected Journal.

Author Response File: Author Response.docx

Reviewer 3 Report

The purpose of the research is not clearly presented. 

Experimental plan is unclear as give strange results which not support ideas in the introduction.

Some errors in the units and presentation are described in the attached file.

A mayor revision of the article is mandatory.

Comments for author File: Comments.pdf

Many errors and not expert to an expert presentation? Article is something for experts of interest and probbably from the same expertise field. 

A major revision is mandatory. 

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript.

The authors fully incorporate the comments of the Reviewers. The authors have addressed reviewer queries/comments as outlined in Tables 1, 2, 3, 4, and 5, as presented below.

I would very much appreciate it if this work could be considered for publication in your respected Journal.

Author Response File: Author Response.docx

Reviewer 4 Report

Paper ID: sustainability-2543384

Type:Article
Title: Physical properties of the incorporation of multi-walled carbon nanotubes in sustainable ultra high performance composite cement.

This paper investigates physical properties of the incorporation of multi-walled carbon nanotubes in sustainable ultra high performance composite cement. Although the testing methods and compared results attained in the present study show the importance of the paper, the authors should address the following comments:

1.     Novelty in comparison to recent literature?

2.     MWCNT is very costly. How will it be sustainable?

3.     How did you choose the mixing method? please give a standard or a reference.

4.     How will the authors prove that the dispersion is good?

5.     There should be space between number and unit.

6.     The relevant literature must discuss the results in the paper.

7.     Throughout the text, some typos must be eliminated.

8.     “Although individual MWCNTs can be identified within cementitious matrix, relatively large agglomerations of the long MWCNTs were observed in UHPC-0.6%” . How can authors be sure of this? Because the scale is too small and matrix is heterogeneous.

9.     “Hydration products of Portland cement, namely small fibres of calcium silicate hydrate (C–S–H) and calcium hydroxide (CH) – can be seen in Figure 11” Please show in the Figure.

 

 

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript.

The authors fully incorporate the comments of the Reviewers. The authors have addressed reviewer queries/comments as outlined in Tables 1, 2, 3, 4, and 5, as presented below.

 

I would very much appreciate it if this work could be considered for publication in your respected Journal.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Corrections have been made and the questions answered.

Author Response

Review 1: Corrections have been made and the questions answered.

Authors: The authors thank for the positive response of the Reviewer to the publication of the paper in the present form.

Reviewer 2 Report

The authors have addressed all the queries. The article may be accepted in its present form. 

Author Response

Review 2: The authors have addressed all the queries. The article may be accepted in its present form. 

Authors: The authors thank you for the positive response of the Reviewer to the publication of the paper in the present form.

Reviewer 3 Report

Improvements are made but quickly and not with the necessary research care.

Mayor revision should be done with care and precision.

Comments for author File: Comments.pdf

Minor revision is needed. Mostly good.

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript. The comments of Reviewer 3 are addressed in the following table.

 

Table 1 - Reviewer #3 (Round 2)

 

1) 72 references are too much it should be from 15 to 25	The authors thanks reviewer comment. After discussion with all authors, the references were kept.
2) List of abbreviations is not necessary if they are declared in the text Language should be corrected, 87 % from 100% reached now.	The authors thanks reviewer comment.  List of abbreviations  was removed.
Experimental plan is strange as results are unusual and why elements of w/b factor are not corrected as consistency change dramatically, and so on…? STILL REMAIN!	The authors thanks reviewer comment.   The w/b was kept constant in all mixtures, as explained in the section 2.2 of the manuscript. As also discussed in section 1 and 3, the consistency change is common when CNT are incorporated in cement-based materials.
In the abstract a electrical resistivity is given (Ω*m) and not conductivity in S/m why do we have two presentation of same property? Some discrepancies fond in the text: Line 103 electrical conductivity can range from 0.01 to 1 S/m[26]. In the literature [26] different data are given 104 S/m to 0.01 S/m what is probably wrong data. Acc. To literature CNT have electrical conductivity in range 104 to 107 S/m. Again one mistake can cause another one! Study deeply electrical conductivity and resistivity of material to understand units!
Figure 3 cancel part (a) AGAIN WHO WANT TO SEE BLACK POWDER IN THE CAN?	The authors thanks reviewer comment. Figure 3-a  was removed.
Table 2 Specific surface area can not be in range but is value of used material? Units are corrected but how one material can have SS in range 7.5 times apart?
Line 293 Electrical measurements. Unify this measurement present el. Conductivity or el. Resistivity consistently in all manuscript! Why presenting one property to ways this complicate and cover results understanding. What is usual practice in among construction engineers? Line 317 units of conductivity (Ω-1m-1) change to Siemens per metre (S/m) or 0.032 is 32 mS/m

 

 

 

Author Response File: Author Response.docx

Reviewer 4 Report

The authors have made the necessary changes. Therefore the manuscript can be accepted. 

Author Response

Review 4: The authors have addressed all the queries. The article may be accepted in its present form. 

Authors: The authors thank you for the positive response of the Reviewer to the publication of the paper in the present form.

Round 3

Reviewer 3 Report

As given in the attached file, some questions still appear.

Comments for author File: Comments.pdf

Minor adjustments.

Author Response

The authors would like to thank the time and constructive criticisms of the referees in reviewing this Manuscript. The comments of Reviewer 3 are addressed in the following table.

 

Table 1 - Reviewer #3 (Round 3)

 

1) Authors want to keep all references, free choice?	The authors thank the reviewer's comment. After discussion with all authors, all the references were considered relevant and kept in the paper.
2) It seems electrical resistivity is common word in authors profession. Language should be improved 80% score reached now.	The authors thanks reviewer comment.  Indeed, electrical resistivity is common word in authors profession. The language was improved.
3) Some discrepancies fond in the text: Line 82 electrical conductivity of CNT can range from 0.01 to 100 S/m[26]. In the literature [26]  different data are given 104 S/m to 0.01 S/m what is probably wrong data. Acc. To literature CNT have electrical conductivity in range 104 to 107 S/m. Again, one mistake can cause another one! Check again to declare correct properties. Some articles like: K. Kaneto, M. Tsuruta, G. Sakai, W.Y. Cho, Y. Ando, Electrical conductivities of multi-wall Carbon nano tubes, Synthetic Metals, Volume 103, Issues 1–3, 1999, Pages 2543-2546, ISSN 0379- 6779, https://doi.org/10.1016/S0379-6779(98)00221-5. tell us different story, conductivity range from 1-2 105 S/m what is perfect conductor. A range from literature [26] tell us that CNT can be perfect conductor 100 S/m or an insulator 0.01 S/m and this seems to me mistaken if we are talking about CNT.	The authors thank reviewer's comment.  The discrepancies were corrected. However, it is possible that CNT varies its electrical conductivity properties, due to multi-walled carbons, synthesis, treatments,  diameter, structural defects, purity and functionalization, synthesis method, aggregations, and measurement method. However, the paper is related with MWCNT that is addressed in paper [26] as presenting electrical conductivity ranging from 102 to 10-4 S/cm[26]
5) Table 2 Specific surface area cannot be in range but is value of used material? Units are corrected but how one material can have SS in range 7.5 times apart? Data in the table are from some technical list of material not from material used in experiments. If this is true than you do not know what you use in the experiments. Hawe specific surface 40 m2/g or 300 m2/g means totally different properties of material?	The specific surface area of carbon nanotubes (CNTs) can vary widely depending on several factors related to their structure and synthesis methods. The specific surface area refers to the amount of surface area per unit mass of material and is often measured in square meters per gram (m²/g). The variation in specific surface area of carbon nanotubes, such as from 40 m²/g to 300 m²/g, can be attributed to the following factors: diameter, structural defects, purity and functionalization, synthesis method, aggregations, and measurement method.
Figure 6 Electrical measurements. Unify this measurement present el. Conductivity or el. Resistivity consistently in all manuscript! Why switch to conductivity here but in other part of text present a resistivity? Maybe you want here to tell that conductivity fall within 28 days and falling what is a promising result.  I am OK with this.	The authors thanks reviewer comment.

 

 

 

Author Response File: Author Response.pdf