Physical-Mechanical and Electrical Resistivity Properties of Cementitious Mortars Containing Fe3O4-MWCNTs Nanocomposite
, Ahmet Sarı 4,5, Ali Yaras 6, Osman Gencel 7,*, Aliakbar Gholampour 8 and Togay Ozbakkaloglu 9,*
Round 1
Reviewer 1 Report
The authors conducted a study on cementitous mortars with Fe3O4-MWCNTs nanocomposite. The paper is good but it needs improvement
Abstract should present most important outcomes of the study
Novelty statement should be improved
The following very recent studies on carbon nanotubes (CNTs) can be added line 52-55 to show their excellent properties: Buckling Analysis of CNT-Reinforced Polymer Composite Beam Using Experimental and Analytical Methods; Experimental and Analytical Investigation of Flexural Behavior of Carbon Nanotube Reinforced Textile Based Composites; Experimental tensile test and micro micro-mechanic investigation on carbon nanotube reinforced carbon fiber composite beams
The reason of selecting mix design should be explained
There is significant decrease in unit weight of MAC3. Why?
Why compressive strength of MAC2 higher than MAC1 for 7 days not 28 days
For all results in each figure, standart deviations for all samples seems to be same. There is some mistake here I guess
Please add damaged photos of samples
Add recent studies on this subject to introduction. There are many studies on the introduction for this topic.
Conclusion should be improved. The recommendation consdiering all test should be given for engineers.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
1- In the present study, to investigate mechanical, durability, microstructural and electrical conductivity properties of mixes, Fe3O4-MWCNTs nanocomposites were synthesized utilising the technique of chemical vapour deposition (CVD) unit of iron oxide (Fe3O4) and multi-walled carbon nanotubes (MWCNTs), and Fe3O4-MWCNTs nanocomposite (MAC) were added to mortar mixes at different replacement levels of 1, 2 and %3.
2- The abstract section gives the summary of the work including study’s aim, methodology and some results in a brief way which is appropriate.
3- The “literature review” has been explained well. According to authors (Lines 118-121): “The reason why Fe3O4-MWCNTs nanocomposites are used in concrete is to improve the electrical conductivity of cement composites and thus to easily dissolve the icing that occurs on the concrete surface in cold regions with low voltage electric current”. Is this the only gap of the research?
4- The research theory, research methodology and techniques of the present work have been explained well. Tables and figures clearly and easily show data visually.
5- Add standard limits to the Figure 1 (particle size distribution).
6- Lines 279-281, “As can also be seen in the figure 9, the inclusion of 1, 2, and 3% Fe3O4-MWCNTs nanocomposite reduced the 7-day compressive strength values by ~47, 42 and 60%, respectively”. The reduction in 7-day compressive strength compared to reference is up (MAC1) then down (MAC2) and up again (MAC3). Add more discussion and how do you justify?
7- Additionally, according to the previous work using Fe3O4 and MWCNTs individually (lines 288-295), opposite results (higher compressive strength) have been obtained. How do you justify? and compare with the present study’s results.
8- Lines 313-316, “By comparing Figures 9 (a) and 10, an increased porosity of the mixture caused a decrease in the compressive strength, which indicates that the results of porosity were aligned with those of compressive strength values reported in section 3.2.2”. This correlation can be shown in a figure.
9- In Section 3.2.5 (Sorptivity or water absorption by capillary action): The rate of initial water absorption, which is referred to as the water absorption coefficient (WAC) and expressed as the slope of the initial part of the curves (e.g. after ~24 sec 0.5) shown in Figure 12. Further explanation and discussion is recommended.
10- Section 3.2.7: The reasons behind reduction in UPV values have been explained however, the UPV guidelines/classification/standard is recommended. For example, how do you classify the concrete with UPV value of 4.612km/s?
11- Correlation between compressive strength and UPV values is recommended.
12- The conclusions perform the findings of the present study in a concrete manner and the successful use of Fe3O4-MWCNTs nanocomposite to improve the electrical conductivity properties however, in contrast decreasing some other properties including compressive strength. Add more discussion in this regard.
13- The references are appropriate.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
Review report. Minor corrections.
The manuscript “Physico-mechanical and electrical resistivity properties of cementitious mortars containing Fe3O4-MWCNTs nanocomposite” analyzes possibilities of manufacturing of smart and electrically conductive products. To address this, iron oxide (Fe3O4)-multi-walled carbon nanotubes (MWCNTs) nanocomposites were synthesized by chemical vapor deposition (CVD) and incorporated to the cementitious mortars as a substitute for sand at 1, 2 and 3% ratios to conduct electricity. Results reveal that the electrical resistivity of cementitious composites decreases (due to the increase in electrical conductivity) from 208.3 to 61.6 23 Ω.m with both the Fe3O4-MWCNTs nanocomposites ratio and the increasing voltage.
The manuscript deals with highly novel and interesting theme. The results are useful for actual industrial and manufacturing practice. Research is scientifically sound and original.
The manuscript is relevant for the field. The text is clear and the experiment is presented in a well-structured manner.
- Abstract is informative. It covers all of the main points of the work.
- Keywords are adequate.
- Introduction: the provided review of literature is clear, comprehensive and of relevance to the field. Authors identified the gap in knowledge and highlighted it in the last paragraph. Introduction could be slightly shorter. Some paragraphs could be abridged.
- Materials and methods chapter:
Line 131: the unit for specific gravity is missing.
Table 1: Chemical composition, setting time, specific gravity and fineness are not ‘physico-chemical’ properties.
Please provide information on Loss on Ignition (Table 1)
There is no unit provided for setting time. (Table 1)
Figure 1: percent fiber on y axis?
Table 3 is not necessary. Methods can be mentioned in the text. Instrumental methods (XRD, SEM….) should be described – applied instrument(s), conditions, type of the sample, etc.
- Result & Discussion chapter gives a clear presentation of results. Everything seems scientifically sound. The experimental design is appropriate to test the hypothesis. There are no errors of fact and logic.
- The conclusions are adequate. They follow the findings highlighted in the Results & discussion chapter.
- The cited references are appropriate and up-to-date (within the last 5 years or so). Used literature is relevant. There is no excessive number of self-citations.
- The text should be read and corrected by English language native speaker or professional proof-reader.
The text should be read and corrected by English language native speaker or professional proof-reader.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The paper can be accepted
