Resistance to Fatigue in Asphalts Used in Military Airports of the Brazilian Amazon through the Use of Nickel-Holding Ash

Round 1

Reviewer 1 Report

 

1. Generally speaking, the structure of the article is unreasonable, and the background introduction of chapters 2 and 3 is too long. For example, sections 3.1 and 3.2 of Chapter 3 almost summarize the existing research content or basic knowledge. Is such a introduction necessary?

Since this paper does not focus on the experimental evaluation of fatigue damage, it is only one of several mechanical behavior tests, but a very detailed or even too much description is given in 3.3, so please consider that whether the length should be reduced. Also the main research contents of the chapters 5 and 6 are too simple.

The introduction of the military airport in Chapter 2 is slightly abrupt, which is not properly connected with the context. Except for Chapter 2, the full text rarely mentions "Military", which is inconsistent with the "remote" in the title. It overemphasizes strategic and political factors, and should strengthen the relevance between the preceding and the following on the basis of reducing the length.

2. The purpose of this paper is to evaluate the mechanical behavior of this mixture. A relatively complete experiment has been carried out, but there is no good information provided to improve the topic. For example, although the creep experiment has been carried out in this paper, the fatigue parameters are only mentioned in the conclusion to evaluate the performance of hot asphalt mixture with the addition of boiler ash. The integrity of the supplementary conclusion can be considered, and the effect of "improvement" can be simply summarized.

3. The title of section 3 of Chapter 5 is wrong.

Author Response

Response Letter to the expert reviewer # 1

 

Dear expert reviewer,

 

As authors of the manuscript now entitled “Resistance to fatigue in asphalts used in military airports of the Brazilian Amazon through the use of nickel-holding ash”, we appreciated a lot your suggestions and comments on the document, as we are certain and convinced, that they have been useful to enrich the fluency and clarity of the entire article. We also confirm that the writing in English has been thoroughly reviewed and accordingly improved.

 

Below, we will detail the changes made and you will be able to find them all exposed and answered since the responses to each suggestion and comments are given in italics.

 

 

Review#1

1. Generally speaking, the structure of the article is unreasonable, and the background introduction of chapters 2 and 3 is too long. For example, sections 3.1 and 3.2 of Chapter 3 almost summarize the existing research content or basic knowledge. Is such a introduction necessary?

R.: The introduction is necessary since the research focuses on the runways for military purposes, which marks a great difference to the existing commercial runways in Brazil. Hereby, the military runways located in the Amazon, having a purpose related to security and defense in each sector of responsibility. However they differ technically from the other developed runways, because their air traffic is not significant, and their maintenance is temporary while the budget assigned is for their conservation being undoubtedly very limited.

Furthermore, the regulations for the construction of military tracks are complied below international technical parameters. However, the lack of preventive and corrective actions for their optimal operation, the strategic and military importance, allow their continuous conservation.

 

Since this paper does not focus on the experimental evaluation of fatigue damage, it is only one of several mechanical behavior tests, but a very detailed or even too much description is given in 3.3, so please consider that whether the length should be reduced. Also the main research contents of the chapters 5 and 6 are too simple.

R.: The research highlights the asphalt damage due to fatigue, because it has been demonstrated that it is the main reason that causes deformations in the pavement structure in the particular case of airports for security and defense purposes in the Brazilian Amazon. However, an additional cause is the determining factor of the temperature, even more so characterized in high temperatures as occurring in the Brazilian Amazon region. These relatively high temperatures oscillate above 40 ºC, and reach up to 80 ªC due to the heat accumulated in the asphalt, which, when subjected to a point load, suffers deformations that are the main reason for the present investigation and the main consideration of fatigue damage.

We reduced accordingly parts of 3.3

 

The introduction of the military airport in Chapter 2 is slightly abrupt, which is not properly connected with the context. Except for Chapter 2, the full text rarely mentions "Military", which is inconsistent with the "remote" in the title. It overemphasizes strategic and political factors, and should strengthen the relevance between the preceding and the following on the basis of reducing the length.

R.: The investigation undoubtedly covers in chapter 2, everything related to the field of security and defense as an important background to justify the need to analyze the risk that would mean not having an infrastructure that provides the best conditions of use of runways for aircraft in the Amazonian sector, considering that the security risk due to border factors is high.

This analysis of the military infrastructure is the preamble to address the importance of the structure of the pavement to be used and to consider the study developed in the article, which ultimately determines how the best conditions for runways that have not had timely maintenance increase and corrective.

Based on your observation, we added military in the title of our manuscript.

 

2. The purpose of this paper is to evaluate the mechanical behavior of this mixture. A relatively complete experiment has been carried out, but there is no good information provided to improve the topic. For example, although the creep experiment has been carried out in this paper, the fatigue parameters are only mentioned in the conclusion to evaluate the performance of hot asphalt mixture with the addition of boiler ash. The integrity of the supplementary conclusion can be considered, and the effect of "improvement" can be simply summarized.

R.: We may disagree here, as especially the graphics of the experimental results highlight the core of our research together with the corresponding explanations. You may or hopefully reconsider this statement.

 

3. The title of section 3 of Chapter 5 is wrong.

R.: Changed as observed and noted.

 

Once again and with all due respect, we are very thankful for your comments and corrections, which helped to see a few unclear parts and or even faults of our side within our manuscript. With your comments we were able to smooth the text, clarify missing parts or wrong spellings, which resulted to a much better than the initial version of this current study. Thanks a lot on behalf of all authors

Reviewer 2 Report

1. Title lengthy and not reflected to content of study.

2. Abstract lack of information. Background, gap/problem statement, aims/objectives,  summary of method and novelty are not clearly presented.

3. Introduction. What main gap between current & previous study? not clearly stated.

4. Why authors choice Brazilian military airports as review study? what about others? should be explain in details.

5. Classification of pavements are too general explanations. What the correlation with main title & objective study?

6. "classification of ash on pavements". What the correlation ash with current study? not clear. 

7. "The use of waste in pavement construction.....". Any correlation with waste and main title? not explain briefly. 

8. There are many sub section not reflected to main title & main content. 

9. What is Tested Mixtures?

10. Fig. 6. Creep test or creep results?

11. Table 8. More discussions are needed.

Author Response

Response Letter to the expert reviewer # 2

 

Dear expert reviewer,

 

As authors of the manuscript now entitled “Resistance to fatigue in asphalts used in military airports of the Brazilian Amazon through the use of nickel-holding ash”, we appreciated a lot your suggestions and comments on the document, as we are certain and convinced, that they have been useful to enrich the fluency and clarity of the entire article. We also confirm that the writing in English has been thoroughly reviewed and accordingly improved.

 

Below, we will detail the changes made and you will be able to find them all exposed and answered since the responses to each suggestion and comments are given in italics.

 

Review#2

1. Title lengthy and not reflected to content of study.

R.: We changed accordingly to your comment and hope to have now a more adequate and corresponding title, reflecting the content of our manuscript. (Resistance to fatigue in asphalts used in military airports of the Brazilian Amazon through the use of nickel-holding ash).

 

2. Abstract lack of information. Background, gap/problem statement, aims/objectives,  summary of method and novelty are not clearly presented.

R.: Great observation, which has led to an almost complete change and better focus to the content and aim of our study. The abstract has been changed accordingly.

 

3. Introduction. What main gap between current & previous study? not clearly stated.

R.: We added in the last paragraph the decisive definition of being an innovative mixture to be applied in the asphalts of remote military airports, with the use of an asphalt binder (nickel-holding ash) which is usually harmful to the environment but here used efficiently and in a clean form.

 

4. Why authors choice Brazilian military airports as review study? what about others? should be explain in details.

R.: In chapter 2 it is stated that the Brazilian military airports, mainly those located in the western Amazon, unlike the airports used for commercial use, do not have a preventive maintenance process and much less corrective. The importance of these runways has a connotation framed in the security and defense used by the Brazilian Armed Forces. Such lack of maintenance to the military tracks, according to the performed research in the present manuscript, demonstrates that the inclusion of a residual fine material is extremely useful, being obtained as a product of the extraction of nickel through blast furnaces, an element that happens to be part of the waste statistics that usually harm the environment (nickel ash).

 

5. Classification of pavements are too general explanations. What the correlation with main title & objective study?

R.: The general classification of the pavements exposed in chapter 4, allows to evaluate the design of the pavements in the military tracks of the western Amazon of Brazil, being a basic design of the infrastructure. However the vulnerability that it presents due to the climatic conditions and the lack of maintenance, cause the structure to weaken. The current research allows to demonstrate that the incorporation of the material (nickel-holding ash), provides better technical conditions avoiding the deformation caused by the fatigue of its elements that comprise it.

 

6. "classification of ash on pavements". What the correlation ashwith current study? not clear. 

R.: In chapter 4 and as part of the classification of materials, the fine material of the structural element is found, which serves as the cementing material of the arid and rocky (stone) elements. The fine material (nickel-holding ash) in the present research study forms part of the pavement structure, and the study demonstrates how this material, in different dosages and tests, improves the rigidity of the structure, allowing better Structural technical conditions, towards the adverse climatic conditions of the sector that has been the study area, the western Brazilian Amazon.

 

7. "The use of waste in pavement construction.....". Any correlation with waste and main title? not explain briefly. 

R.: The title of this study highlights the use of a residue as a result of nickel mineralization, in whose process, this metal expels fine residues that accumulate inside or in the surroundings of high temperature furnaces. This fine-grained material (ash) indicates that it has cementing characteristics as well as rigidity that have been applicable in the solution to the problem that military tracks have in the western sector of the Brazilian Amazon. The pavement structure with the new material included (nickel-holding ash) demonstrates through the described tests and trials, that in all of them the technical and resistance characteristics improve considerably.

 

8. There are many sub section not reflected to main title & main content. 

R.: There is a new proposed change in the title, which may reflect better the content of the manuscript (Resistance to fatigue in asphalts used in military airports of the Brazilian Amazon through the use of nickel-holding ash)

 

9. What is Tested Mixtures?

R.: The applied mixtures throughout our research are named tested mixtures.

 

10. Fig. 6. Creep test or creep results?

R.: Creep test result, corrected as observed

 

11. Table 8. More discussions are needed.

R.: We added accordingly:

The table lists the results of the fatigue test performed on two samples (M1 and M2), related to figure 2, where a traditional structure of the asphalt pavement stands out, and M2, which adds a percentage of the residue of the nickel mineralization (nickel-holding ash).

Round 2

Reviewer 1 Report

I still think there are too many irrelevant contents and descriptions in this manuscript. It is more like a project report, not a journal paper. Please focus on the research objectives.

Author Response

I still think there are too many irrelevant contents and descriptions in this manuscript. It is more like a project report, not a journal paper. Please focus on the research objectives.

 

Thanks you. We did so, and shortened parts of this kind of text and explanation for another additional 923 words. You will see these changes in the resubmitted manuscript.

Reviewer 2 Report

1. There are no UNITS for all figures presented. Example, fig. 1. What the unit for Gmm of the mixture? ASPHALT PETROLEUM CEMENT CONTENT, it is %?. Not clear. Resilience Module, what the unit? Amount of CAP, percentage? Check for all figures.

2. What is RT & MR in table 4? full name following by abbreviation.

 

Author Response

 

There are no UNITS for all figures presented. Example, fig. 1. What the unit for Gmm of the mixture? ASPHALT PETROLEUM CEMENT CONTENT, it is %?. Not clear. Resilience Module, what the unit? Amount of CAP, percentage? Check for all figures.

 

R. Thanks for these meticulous observations. We guess, you meant a different figure, as figure 1 is an illustration of different types of rigid pavements and the only unit is the length expressed in centimeters and meters. Figure 2 is a schematic illustration. Figure 3, ASPHALT PETROLEUM CEMENT CONTENT the % was missing (we missed that, great catch!), also in the following figures. We corrected all of them. Thanks for that. Gmm appears first in table 7 where it is explained to represent the measured specific mass (gram per measured mass)

 

What is RT & MR in table 4? full name following by abbreviation.

R. That’s correct too, and also useful for us not to mention it as late as shortly before table 7 rather than when they first appear in the text.

 

You will see these changes in the resubmitted manuscript.

Round 3

Reviewer 1 Report

No more comments.