Enhancing Moisture Damage Resistance in Asphalt Concrete: The Role of Mix Variables, Hydrated Lime and Nanomaterials

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors This paper deals with methods to enhance the moisture damage resistance of asphalt mixtures, which involves a number of factors and appears to be a bit cluttered. It is more desirable to make an in-depth analysis for one of the points, such as the effect of nanomaterials on moisture damage resistance. There are still some big problems with the article, and the following are specific examples: 1. The title is inappropriate and the word “modifiers” encompasses too much. 2. Please note the consistency of specialized terms such as “asphalt concrete” and “asphalt mixture”. In addition, the language of this paper needs further improvement. 3. Abstract, the authors are conveniently less descriptive in their results and conclusions, which do not reflect the reasons for the effects of HL, NS and NT modifications, and need to be recondensed. 4. As the authors summarize the fact in Table 1 that asphalt mixes reach their best performance under OAC, I don't understand why the authors still want to study the effect of AC? The results are also as we expected and the authors got the conclusion that the best performance is also achieved in the OAC case. 5. Fig. 1. Why is a range of 6% used? What is the rationale? 6. 3. Experimental Tests, a table should be added to this section to describe all the mixing ratios and corresponding test items covered in this paper. 7. The law of the effect of HL on the physical properties of asphalt should be added. 8. There is absolutely no need for “4.2. Marshall Test” to appear in “4. Results and Discussion”, which is a routine step in the design of asphalt mixtures. 9. If the aggregate gradation of an asphalt mixture changes, then its OAC must also change, and in “4.2. Marshall Test” the authors fixed the OAC of the other groups to be 4.9% as well, and I am skeptical of the results. Comments on the Quality of English Language

Need major revised.

Author Response

The authors wish to thank the reviewer for the time and effort in reviewing our manuscript. The provided comments and constructive suggestions are very helpful in improving the quality of our manuscript and have helped us identify several shortcomings in our manuscript. All the provided comments were addressed.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, the enhancing moisture damage resistance in asphalt concrete: the role of some mix variables and modifiers was partially studied, and certain research results were obtained. The work of this manuscript is innovative to a certain extent, and the workload is OK, but the overall writing and drawing level is poor, and the layout of the manuscript needs improvement.

(1)    There are too many keywords, and the first letter of the keyword should be capitalized.

(2)    There is a lack of references in the first paragraph of the introduction. We should refer to every judgment sentence in the manuscript and not just cite one or two references for a long paragraph. Please supplement the corresponding references for the first paragraph of the introduction. At the same time, please check the full text and supplement references elsewhere, such as the first sentence of the second paragraph of the introduction, and the third paragraph of the introduction.

(3)    The last paragraph of the introduction does not highlight the value of the research well, the research methodology is stated in too general a manner, and the objectives of the research are missing, please rewrite the last paragraph.

(4)    The drawing of Figure 1 is too poor, the units in the figure need to use brackets, please redraw.

(5)    In Table 6, "25-60" should be changed to "25~60", please check the full text and modify similar problems.

(6)    All the figures in the manuscript need to be redrawn.

(7)    Section 3.3, the equation layout format needs to be optimized.

(8)    Can the author explain that the green error bars in Figure 9 are the same length, and the blue ones are also the same length? As well as the error bars in Figure 10 to Figure 16, the error bars in the manuscript are used incorrectly, and this kind of data lacks reliability.

(9)    Lack of micro test, if there is a micro test to prove water damage resistance will be better.

(10) At the end of the conclusion, it is necessary to supplement the limitations of this study and the next research plan.

Comments on the Quality of English Language

The English language needs a lot of revision, and it is best to ask native language editors to polish it.

Author Response

The authors wish to thank the reviewer for the time and effort in reviewing our manuscript. The provided comments and constructive suggestions are very helpful in improving the quality of our manuscript and have helped us identify several shortcomings in our manuscript. All the provided comments were addressed.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for submitting an interesting paper dealing with an important topic. The paper is very well written and easy to follow. Although the overall point of mixture volumetrics and additives  being important factors in mositrue damage of asphalt mixtures is made well there are many times in the paper where the interpretation is not always clear or in line with other research, in particular in mechanism of how hydrated lime is considered to function. Also the role of the surface in stiffening binder is discussed but not the bulk properties of the fillers, which is the major factor in stiffening (if you consider this as  a classic suspension). I think that some reinterpretation of the work is necessary.

Line by line comments

40. Does the asphalt "soften" as a result of losing cohesion?

61. How is the "surface energy" altered?

114. Please explain what SCRB is

117. It would be good for the sieve sizes to be also presented in metric values for the reader

157. I am not sure about the effect of HL being drivne by mechanical interlock? There is nothing in the explanation about either the chemical behaviours at play here (especially as you are using a siliceous aggregate) or any potential extension of the binder by the finer particles of the HL

176. Stiffening is a function of bulk properties and so i am not sure that these high effective volume particles will be "easier to mix" as they are spherical?

179. Again stiffening is primarily a function of solid volume not surface area.

268. Penetration is a logarithmic property so I am not sure if presenting % change is useful

407. I do not agree with this interpretation at all. Increase "adhesion" through the filling of voids? Adhesion is a fundamental property an a function of the 2 materials.

418. Again I do not agree (and neither do many researchers) that roughness is the driving force for how HL works in bitumen

421. Why does better packing influence "adhesion" I am not sure it does...

Author Response

The authors wish to thank the reviewer for the time and effort in reviewing our manuscript. The provided comments and constructive suggestions are very helpful in improving the quality of our manuscript and have helped us identify several shortcomings in our manuscript. All the provided comments were addressed.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The revised manuscript has already met the requirements of the journal, so I have no other comments.