Preparation and Performance Test of UV Resistant Composite-Modified Asphalt

Round 1

Reviewer 1 Report

Interesting paper on performance test of UV-resistant of modified bitumens, but some details must be clarified or corrected/completed:

1.       Introduction: you should include more references and discussion of PMB’s ageing and UV degradation of bitumen and polymers. Only 20 references were cited, and the literature review should also be extended for the newest and older publication in the topic.

2.       Table 1 – please provide a result of Recovery Elastic (RE) from a ductile test as a PMB indicator. Please provide the deformation energy value from the tensile force ductility method. Ductility, in the case of PMB, says nothing.

3.       Please provide the details about a self-developed ultraviolet ageing oven, e.g. UV lamp (producer, thermal resistance, max. working temperature etc.).

4.       Fig. 2. And Fig. 3. – please change the linear graphs into bar graphs. How many repetitions did you make? Please provide the error bar in the charts.

5.       All text in the manuscripts: “technical indexes”, “routine indexes” etc. – wrong statements. It should be modified into the “………… properties” instead of indexes, etc.

6.       Rows 153-155: “Scheme E, F, G, J, K and O based on conventional indexes and cost” – please provide cost analysis and methodology.

7.       Section 3.2.3. Fatigue resistance: please significantly extend this section. Please provide the fatigue curves as a function of time/cycles. Please explain how many repetitions you did for every single bitumen. What strain level did you use? In Fig. 8, please add error bars.

8.       All manuscripts and especially fig. 9.: please vary colours on figures related to the groups of modifiers used. Giving sample notation like “A G K F J O E” is correct but significantly impedes perception.

9.       Conclusion 2: it does not follow the presented studies and data. No economic analysis is provided in the manuscript.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The studies on the preparation  and performance test of UV resistant composite modified asphalt are interesting both from scientific and practical point of view.

1.       Regarding Figures 2 and 3, there is no information for which samples the test results are presented.

2.       Verse 130 (page 5) in the text is "Brinell viscosity." It should be "Brookfield viscosity".

3.       The authors of the paper, in section 3.1, refer to storage stability. Were stability measurements performed for the samples tested?

Author Response

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Reviewer 3 Report

The topic of the paper is interesting and needs minor improvements. Some comments were listed for paper corrections.

1. Please change Brookfield viscosity by "apparent viscosity"; one Brookfield refers to a brand of a viscometer.

2. Please introduce a photo of the laboratory experiments. Change Figure 1 or add a figure from the actual experiment.

3. Highlight the novelty of your paper.

4. Discuss the paper's limitations.

5. Provide a careful English grammar revision.

Author Response

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Reviewer 4 Report

Manuscript reports the results of an experimental investigation on UV Resistant Composite Modified Asphalt adding nano-montmorillonite and carbon black. The topic is interesting, and the research well conducted in terms of experimental plan and discussion of the results. 

I suggest some minor modifications aimed at improving the manuscript.

1) In Literature review I suggest to insert the following manuscript: doi: 10.1163/157361106776240761

2) Please provide deeper information about the price of nano-montmorillonite, carbon black. It could be useful to highlight the environmental benefit of the use of carbon black derived from waste tire.

3) It could be interesting in a future development of the research, based on a case study, assessing the benefit of the improvement of the UV-aging resistance using the nano-montmorillonite, and carbon black in terms of lifetime span of the pavement. This evaluation could consider simultaneously the effect of the improvement in UV-aging resistance and the decrease of low temperature and fatigue resistance.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors made all corrections related to the reviewer's comments.