Statistical Approach Model to Evaluate Permanent Deformation of Steel Fiber Modified Asphalt Mixtures
, Ahmad Kamil Arshad 1,2, Nuryantizpura Mohamad Rais 2,4 and Zaid Hazim Al-Saffar 5,6
Round 1
Reviewer 1 Report
C1) They are a simple study, not very original nor very significant, because the influence of steel fibers (SF) on SMA were studied and published quite substantially so far. In these studies from literature, the object of study was also the asphalt mixtures.
C2) The novelty of the topic is questionable in some way. Many of these results are expected from previous studies made by other authors. The originality of the experimental part is also questionable because the authors published in 2020 and 2021 papers where the experimental investigations were conducted quite similar and some drawn conclusions are quite similar. I mean about the paper referenced here with [7] "Mechanical Performance of Stone Mastic Asphalt Incorporating Steel Fiber " published in IOP Conferences Series: Materials Science and Engineering and the reference [16] "Performance Characterization of Stone Mastic Asphalt using Steel Fiber" published in Journal of Advanced Industrial Technology and Application 2 (2), 22-33. Studying the experimental part in these two papers regarding stability and flow tests, and moisture susceptibility it can be noted that the results are pretty similar comparing to what it is presented here. Moreover, regarding the conclusions of these two published articles, it can be noted that in some conclusions are the same in respect with the varying of the studied properties and also optimum content of steel fibers. Therefore, the authors should work on these similarities.
C3) The abstract is too long and also contains information about the various effects of addition of steel fibers already mentioned in the foregoing articles. For example, about the percentage of 0,3% as being the most optimum steel fiber content.
C4) The research motivation, about the use of fibers in asphalt mixture as being an alternative materials that has been demonstrated to increase the stability and resistance against moisture damage of asphalt mixtures in dealing with pavement distresses, is comprised in the Introduction text, but equally the same motivation was used in the mentioned papers already published.
C5) The title of the article is “Statistical Approach Model to Evaluate Permanent Deformation of Steel Fiber Modified Asphalt Mixtures”, but a very significant part of the article seems to be devoted to mechanical performance of stone mastic asphalt incorporating steel fibers. Many results presented in the reviewed article and also the test setup were presented in the mentioned published articles.
C6) In Introduction the authors make many statements about properties and performances of SMA, and its applications. All this statements must be backed (referenced) with publications in well ranked journals or indexed Proceedings.
C7) Some of the figures posted here are also encountered in the mentioned papers. Perhaps, the figures are necessary here too, but the authors should do something in this respect.
C8) The results about Stability and Flow test are quite similar comparing to the mentioned papers. The difference is that here the stability and flow results are presented in different ways. Here the results are included in a table compared to charts in the published papers.
C9) The results about Moisture Susceptability test are quite similar comparing to the mentioned papers. The columns of the presented charts here provide the same results comparing to the charts from published papers.
C10) The conclusions are too general. Within conclusions, the quantitative description of the achieved improvement through using steel fibers is poor. It can be noted that the conclusions are in qualitatively terms not quantitatively.
The manuscript in this shape is to be rejected because has some serious similarities in the way of conducting and presenting the research with the references [7] and [25] . Therefore, the authors have to make a major revision of the manuscript removing similarities.
Author Response
Dear Reviewer,
Attachment is a point-by-point response to reviewer comments and concerns in order to clarify how we revised the manuscript based on the comments and recommendations.
Thank you.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors in the manuscript describe a method of optimizing the amount of steel fibers in modified asphalt mixture and characterize the performance of steel fiber in SMA mixture using the statistical approach of Response Surface Methodology. There are inaccuracies in the manuscript that the authors should clarify. Some wording needs rewording.
In its current form, the article is not suitable for publication in Sustainability.
General remarks
1. It is necessary to write in the thesis why such and not other proportions of steel fibers were chosen. Why wasn't the effect of a higher share of steel fibers investigated? It would be appropriate to check whether the trends of the examined properties do not change with a higher share of steel fibers in SMA.
2. Whether other additives were used in the SMA. It should be described.
3. The steel composition of the steel fibers should be specified. What was the shape and character of the surface of the steel fibers?
4. Calculate the standard deviation and COV in Table 6 for moisture susceptibility..
The article is not well written and needs improvement.
Specific remarks
5. 52 line: In what context is the word "improvising" used?
6. 73 line: Steel fibers belong to polymer fibers?
7. 76 line” increases or decreases sensitivity to moisture?
8. 142 line, Table 1: Should be "kg/m3", "MPa".; aspect ratio: l/d.
9. 177, 204, 207 lines: "where" is written twice.
10. 240 line: Correct the units to "kN".
11 Table 4: Correct the units to "kN".
12. 282 line Fig.6 : On the ordinate axis, correct the units to "kN".
13. 377 line: Should read: "...for moisture susceptibility."
14. Conclusions should be bulleted.
I recommend reviewing the manuscript with comments to make it suitable for publication in Sustainability.
Author Response
Dear Reviewer,
Attachment is a point-by-point response to reviewer comments and concerns in order to clarify how we revised the manuscript based on the comments and recommendations.
Thank you.
Author Response File: Author Response.pdf
Reviewer 3 Report
In this manuscript, the authors showed statistical approach model to evaluate permanent deformation of steel fiber modified asphalt mixtures. The use of English is satisfactory and the article can be followed easily. The title accurately reflects the study. The objective is well defined and I have no criticisms regarding the interpretation of results. However, I think that the article is not ready for publication as it stands. The questions are as follows:
1. In the introduction, you need to connect the state of the art to the model to evaluate permanent deformation of steel fiber modified asphalt mixtures. Currently, this is not performed in a convincing way. Please follow the literature review by a clear and concise state of the art analysis. This should clearly show the knowledge gaps identified and link them to the model to evaluate permanent deformation of steel fiber modified asphalt mixtures. Please reason both the novelty and the relevance of your paper goals.
2. Page 3 line 102-108: The sentence is too long for reading. It is difficult to understand the meaning of this sentence. Please modify it.
3. Before proceeding to describe your experiment, materials and actions, please describe your scientific hypothesis, concepts and the relevant reasoning for choosing the particular modelling approach. This should be accompanied by an overall description of the followed procedure.
4. Page 11 figure 6: This picture looks strange and difficult to read, please refer to other relevant papers in this journal.
5. Please improve the clarity of Figure 7.
6. Page 21-22: There are too many tables, and many of the data are meaningless. Table 10 to Table 15 should be merged or used as additional materials.
7. The structure of the full text is unreasonable, and the article lacks a conclusion. To make the conclusion section more clear, authors are highly encouraged to include the point-by-point findings of this article.
8. The novelty of this work is fair. However, a quick search reveals that this study does not differ significantly from other publications that were published by the authors. The authors are asked to show their original contribution in this field in a more convincing way.
9. If this is an experimental study, I think experimental data should be shown in the corresponding Figure as well as fitting model. How many runs does the experimental procedure consist of ?
10. Please review references format.
Author Response
Dear Reviewer,
Attachment is a point-by-point response to reviewer comments and concerns in order to clarify how we revised the manuscript based on the comments and recommendations.
Thank you.
Author Response File: Author Response.pdf
Reviewer 4 Report
SUMMARY
The article submitted for review is devoted to a topical issue. A model of a statistical approach to evaluate permanent deformation of steel fiber modified asphalt mixtures is considered and presented. This topic is very relevant, because many accidents occur due to damage to the pavement, which in turn occurs due to irreversible deformations caused by external loads and heavy traffic. An important material to prevent this is stone mastic asphalt (SMA). It has low moisture resistance and other characteristics that demonstrate its effectiveness. Of interest are the studies carried out by the authors on the reinforcement of SMA with various types of fibers. At the same time, there is a scientific deficit, which consists in the fact that in the current literature there are few studies on steel fibers in materials such as SMA, while the authors conducted such studies by analyzing them statistically. The authors applied optimization methods, applied interesting laboratory methods, methods of mathematical modeling, design of experiments, and came to an important conclusion that the addition of steel fibers, taking into account the optimal dosage, improves the properties of SMA. Such a method is an efficient statistical method for obtaining suitable empirical models for predicting and correlating inputs and outputs. Therefore, the article has practical significance and scientific novelty. However, there are some shortcomings in the article that should be corrected. They will be discussed below.
COMMENTS
1. The abstract provided by the authors is unnecessarily extensive. The authors are invited to somewhat reduce the methodology and its description in the abstract, limiting themselves to the definition of a scientific problem, research methodology and scientific result.
2. In the Introduction section, the remark is that very few references were considered, only 11. There are a large number of studies on fiber-reinforced asphalt. Authors should strengthen this section. At least 20 references should be analyzed.
3. In the Materials and Methodology section, I would like to see a more detailed justification for the choice of materials and methods.
4. Figures 2 and 3 would like to see in high quality.
5. Table 1 looks uninformative.
6. In general, section 2 looks like a kind of scientific protocol. A more detailed descriptive part should be made so that the article is easily perceived by readers.
7. Figure 6 looks interesting but needs more explanation. The region of interest is in the range from approximately 0 to 300 load cycles and generally between the 0% curves (blue dots) and 0.5% curves (grey line). I would like to see a more detailed interpretation of these dependencies.
8. Probably the format of the bar chart in Fig. 8 and 9 is not well chosen.
9. Figures 10-12 and Figure 14 look uninformative. Authors should use some other kind of presentation of the results.
10. Section 3 is unnecessarily overloaded with results, but the discussion of the results obtained is poorly presented.
11. The authors interpreted their own studies well, but would like to see a comparison of these results with those of other authors. A more detailed discussion should be held and the results obtained should be explained in terms of fundamental dependencies. Probably, the article lacks a SEM analysis or other in-depth research approach to study in more detail the fundamental relationship between the composition, structure and properties of the resulting steel fiber asphalts.
12. The Conclusions section needs to specify the scientific result, it should be slightly corrected.
13. As mentioned above, the list of references is rather small, it should be increased to at least 30 points. At the same time, it is important to give preference to references for the last 5 years, so that the novelty can be seen more clearly.
14. In general, the reviewer's conclusion on the article is positive, after correcting the comments received, the article can be published in the Journal.
Author Response
Dear Reviewer,
Attachment is a point-by-point response to reviewer comments and concerns in order to clarify how we revised the manuscript based on the comments and recommendations.
Thank you.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
C1) The authors improved in some way the manuscript.
C2) The abstract was improved
C3) The remarked similarities with some past published articles were diminished. The References were increased in number in quality.
C4) The conclusions were reformulated in some extent.
Reviewer 3 Report
The author made careful revisions according to the suggestions. The quality of the articles has been improved
