High-Temperature Rheological Properties of Crumb Rubber Composite Modified Asphalt
Round 1
Reviewer 1 Report
This paper present an experimental study on the High-tempmerature rheological properties of crumb rubber added to three types of composites to prepare the crumb rubber composites modified asphalt binder. This study is well presented, organized and provides sufficient experimental results. However, since this investigation is an experimental study, involving some different inputs (the composite additives), and to study their effects on the output (H-temperature rheological properties of CR, the main concern here why the Design of Experiment (DoE) was not used ?. Using this methodology, will organize the experimental protocol on solid bases and provides also the sensitivity of each input fator and its relevance on the outputs. In addition, an optimization of the best input combinaison can be performed.
Author Response
Reply to Reviewer’s Comments for Sustainability-1804599
Title of Paper: High-temperature Rheological Properties of Crumb Rubber Composite Modified Asphalt
Authors: Fangyuan Gong, Weijie Lin, Zhenkan Chen, Tao Shen, Chichun Hu
The authors sincerely thank the reviewers for their comments and suggestions. These suggestions have improved this paper for more clear and concise expression. In the following, the detailed replies to all comments are provided.
The line number in this response letter is based on the version with track changes.
Reviewer #1:
Comment: This paper present an experimental study on the High-temperature rheological properties of crumb rubber added to three types of composites to prepare the crumb rubber composites modified asphalt binder. This study is well presented, organized and provides sufficient experimental results. However, since this investigation is an experimental study, involving some different inputs (the composite additives), and to study their effects on the output (H-temperature rheological properties of CR, the main concern here why the Design of Experiment (DoE) was not used ? Using this methodology, will organize the experimental protocol on solid bases and provides also the sensitivity of each input factor and its relevance on the outputs. In addition, an optimization of the best input combinaison can be performed.
Response: Thanks for the reviewer’s suggestion. The Design of Experiment has been revised in Section 4 of the manuscript.
Reviewer 2 Report
For different types of rubber composite modified asphalt binder for the asphalt bond of high-temperature rheological performance was evaluated in lab tests, which has some practical value. However, there are still problems at some details in the text, as follows:
1. Please verify the format of the reference in line 637.
2. Possible problems with the normative values in Table 1, such as specification index, softening point, dynamic viscosity at 60℃. Please check and correct them.
3. In Figure 4, it is recommended that the viscosity values for different temperatures be analyzed using a fit rather than simply using a line graph for dotted line connections.
4. The authors need to check the serial numbers before Percent recovery in line 442, Stress sensitivity in line 473 and FTIR test in line 505.
5. High-temperature rheological performance should be based on the low -temperature performance requirements. It is suggested that the effect of modifiers on the low-temperature performance of asphalt should also be taken into account in future studies.
6. There are so many entries in the Conclusion that it does not highlight the conclusions and innovation of the study, and the authors are advised to condense the conclusions.
Author Response
Reply to Reviewer’s Comments for Sustainability-1804599
Title of Paper: High-temperature Rheological Properties of Crumb Rubber Composite Modified Asphalt
Authors: Fangyuan Gong, Weijie Lin, Zhenkan Chen, Tao Shen, Chichun Hu
The authors sincerely thank the reviewers for their comments and suggestions. These suggestions have improved this paper for more clear and concise expression. In the following, the detailed replies to all comments are provided.
The line number in this response letter is based on the version with track changes.
Reviewer #2:
For different types of rubber composite modified asphalt binder for the asphalt bond of high-temperature rheological performance was evaluated in lab tests, which has some practical value. However, there are still problems at some details in the text, as follows:
Comment (1): Please verify the format of the reference in line 637.
Response: Thanks for the reviewer’s suggestion. The authors have revised the format of this reference in line 677.
Comment (2): Possible problems with the normative values in Table 1, such as specification index, softening point, and dynamic viscosity at 60℃. Please check and correct them.
Response: Thanks for the reviewer’s suggestion. Normative values in Table 1 have been revised.
Comment (3): In Figure 4, it is recommended that the viscosity values for different temperatures be analyzed using a fit rather than simply using a line graph for dotted line connections.
Response: Thanks for the reviewer’s suggestion. The authors have revised the viscosity values for different temperatures using a fit in line 230.
Comment (4): The authors need to check the serial numbers before Percent recovery in line 442, Stress sensitivity in line 473 and FTIR test in line 505.
Response: Thanks for the reviewer’s suggestion. The serial numbers before Percent recovery in line 421, Stress sensitivity in line 447 and FTIR test in line 476 have been revised.
Comment (5): High-temperature rheological performance should be based on the low-temperature performance requirements. It is suggested that the effect of modifiers on the low-temperature performance of asphalt should also be taken into account in future studies.
Response: Thanks for the reviewer’s suggestion. The effect of modifiers on the low-temperature performance of asphalt would be taken into account in our future studies and addressed in the last paragraph.
Comment (6): There are so many entries in the Conclusion that it does not highlight the conclusions and innovation of the study, and the authors are advised to condense the conclusions.
Response: Thanks for the reviewer’s suggestion. The conclusions have been revised and condensed in revised-manuscript
Reviewer 3 Report
Please find attached a PDF file with my comments for authors.
Comments for author File: 
Comments.pdf
Author Response
Reply to Reviewer’s Comments for Sustainability-1804599
Title of Paper: High-temperature Rheological Properties of Crumb Rubber Composite Modified Asphalt
Authors: Fangyuan Gong, Weijie Lin, Zhenkan Chen, Tao Shen, Chichun Hu
The authors sincerely thank the reviewers for their comments and suggestions. These suggestions have improved this paper for a more clear and concise expression. In the following, detailed replies to all comments are provided.
The line number in this response letter is based on the version with track changes.
Reviewer #3:
This manuscript includes a research about the high‐temperature rheological properties of crumb rubber composite modified asphalt. As a general comment of the manuscript, I think that the topic is interesting and the results presented in the manuscript are relevant. Nevertheless, I have several suggestions in order to improve the manuscript before being published in Sustainability journal.
Comment (1): In relation to the introduction section, in my opinion, the state‐of‐art review of the topic of the manuscript included in this section is adequate, with 27 references cited. In addition, the aim of the work has been adequately described in section 2. However, in my opinion, the novelty of the work and the impact of results presented in the manuscript should be also clearly defined in this section 2. For example, it could be added a new final paragraph explaining this, after the paragraph in which is defined the aim of the manuscript.
Response: Thanks for the reviewer’s suggestion. Authors have revised this section and the novelty of the work and the impact of results have been presented in the manuscript (in lines 77-87).
Comment (2): Sections 3 and 4 are fine, and I think that the materials and procedures used in this work have been well‐described. I congratulate the authors for figure 3 because it is very clarifying. Section 5 is very complete and detailed. Nevertheless, in relation to the discussion of results, I suggest improving it, because most of section 5 of the manuscript is used for describing the results, being their discussion slightly short. In addition, I think that more references must be cited in this section, in order to support the results obtained and compare them with previous relevant works on the same topic of the manuscript.
In relation to the conclusion section, I like the idea of highlighting the main findings of the manuscript using numbers as bullet points, because this makes the conclusions clearer. In addition, I think that the conclusions obtained in this work are relevant.
Response: Thanks for the reviewer’s suggestion. Section 5 has been revised and some references have been cited in the revised manuscript.
Round 2
Reviewer 3 Report
My comments and suggestions have been fulfilled. Therefore, I recommend to accept the manuscript.
