Life Cycle Assessment of Innovative Asphalt Mixtures Made with Crumb Rubber for Impact-Absorbing Pavements

Round 1

Reviewer 1 Report

The paper is interesting, well-written, and suits the journal aim. I have the following comments for the authors:

1_ Introduction: The term of impact-absorbing pavements (IAPs) is marginally illustrated. Please revise and improve cohesion in the introduction.

2_ Lines 76-77: A brief comparison of dry and wet process should be added either here or in the introduction.

3_ Lines 209-210: Please explain this statement about the contribution of crumb rubber.

4_ Conclusions: Did the authors have any insight about relevant literature to comment on? Please include discussion points, limitations, agreements and contribution to the state-of-the art.

5_ Many acronyms are used. Please consider including a reference list at the end of the paper.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Manuscript Life-cycle assessment of innovative asphalt mixtures made with crumb rubber for impact-absorbing pavements represented the study of a very interesting and hot topic. The authors have applied the life cycle assessment methodology to evaluate the environmental impact of shock-absorbing pavements fabricated with recycled materials.

Generally, the paper has a quality but should be additionally improved.

1.      I advised authors to put “by previous studies [13-15]” instead of put as reported by…. [13-15] in the second paragraph of the introduction.

2.      In the paragraph 6 of the introduction, please give a reference for the sentence: Moreover, previous studies from the authors introduced…. Which authors or previous studies? Please give reference.

3.      The variables used in the aforementioned formula are available in Tables 1 and 4. Is it not only Table 4? Please check and confirm.

4.      I suggested to authors to put the discussion of Figure 3 after instead of before. This means that move the sentence: “As shown in Figures 3 & 4, the bitumen/emulsion plays …...after Figure 3.

5.      What are the limitations of your study?

6.       What are the recommendations for future studies?

7.       Please check carefully the references. Some seems to be incomplete. For instance, [10], [39-41].

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Life-cycle assessment of innovative asphalt mixtures made with crumb rubber for impact-absorbing pavements

Lima et al.

 

Overview and general recommendation for the journal:

 

The article investigates the environmental impacts of different alternatives for the use of rubber asphalt. For this purpose, the authors used a cradle-to-grave life-cycle analysis. I found the work interesting, with useful data for the scientific community, and it is within the scope of the journal.

I have two major questions about the article in its current format and therefore recommend reviewing the article according to the comments below.

 

Major comments:

1. Apparently, the authors made a very superficial analysis of the literature on LCA of asphalt mixtures in paving. This is reflected in the analysis and discussion of the results, which was not compared with previous work.

 

2. The authors investigated five different cases (Table 3). Although they presented most of the input data in the LCA software, I strongly recommend that the authors provide more detail on the input files used. This would help to give more transparency and reproducibility to the simulations performed. Perhaps this information can be provided as supplemental material.

 

Minnor comments:

3. Line 40: user-friendly

4. Line 42: as reported by...?

5. Line 65: ferrotone pigments could be better explained.

6. Line 209: what is the functional unit used? 1 m2 pavement?

7. Line 222: incorporate

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

My comments were satisfactorily addressed. In lines 313-314, please add some explanations in a parenthesis about what is implied by the term "which increased the environmental impacts due to transportation distances", e.g., aging, storage conditions or something else... Please, also amend some language issues throughout the paper. Overall, I believe that the manuscript was improved enough. 

Author Response

Thanks for your comment.

The requested changes have been made.

Reviewer 2 Report

No comment

Author Response

Thanks for your comments.

Reviewer 3 Report

Life-cycle assessment of innovative asphalt mixtures made with crumb rubber for impact-absorbing pavements

Lima et al.

 

Overview and general recommendation for the journal:

 

The authors responded satisfactorily to my comments, with the exception of Comment #1. 

 

I believe that a comparative analysis of the environmental impacts provided by the LCA with previous work should be carried out. Even if the functional unit is different, the authors can comment on the most significant environmental impacts of asphalt mixtures. Here are some possibilities for authors to compare their results and improve the scientific quality of the article.

 

https://doi.org/10.1016/j.conbuildmat.2022.126608

https://doi.org/10.3390/ma14216589

 

Despite this, I now consider a minor revision to be sufficient.

Author Response

Thanks for your comments.

We added a paragraph in the introduction, citing the second paper recommended.