Evaluation of Using Natural Fillers to Improve Moisture Damage Resistance and the Use of Pull-Off Tensile Test in Determining Moisture Damage Resistance in Asphalt Mixture

Round 1

Reviewer 1 Report

Nice compact study combining waste materials replacement in asphalt with the evaluation of a cross-over field test. 

Would be a good idea to add some more statistics on Bagasse and Coconut Peat in introduction, how much of it is available relative to the asphalt production in Thailand? World? You are introducing a new material and it is important to put their potential in context.

Need to add error bars to Tables 2,3, 4; Figures 6,7

A full grammatical review is highly recommended

Grammar Mistakes in Abstract:

L4: contribute-> allow

L21: add period after 'test'

Author Response

1. Would be a good idea to add some more statistics on Bagasse and Coconut Peat in introduction, how much of it is available relative to the asphalt production in Thailand? World? You are introducing a new material and it is important to put their potential in context.

- We added some more statistics on Bagasse and Coconut Peat in introduction, how much of it is available relative to the asphalt production in Thailand.

2. Need to add error bars to Tables 2,3, 4; Figures 6,7
- Please see attached file version. We have edited according to your comments

3. A full grammatical review is highly recommended

- We have looked into the whole manuscript and amended the mistakes.

Grammar Mistakes in Abstract:

L4: contribute-> allow

-we have changed, please see in abstract

L21: add period after 'test'
-we have changed, please see in abstract

Thank you so much for your comments. Please see the revised version as attached.  

 

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper is well-written and describe test and test results well, but it lacks some discussions behind the two tests. The reviewer has several comments as follows:

1. What does AC60-70 mean? Please show PG grade is possible.
2. It should be mentioned the reason why there is difference between TSR in IDT and that in POTS (e.g. some equations to show the difference). 
3. It seems the two tests in wet condition were not at same temperature (one is 60C, one is 64C).
4. If the TSR results passes the specfication, how about other test results (cracking and rutting) for the same material combination (e.g. bagasse or coconut peat)? Can they still pass the tests?
5. It may be worthy to discuss some factors and more materials to check the the usefulness of POTS.

Author Response

1. What does AC60-70 mean? Please show PG grade is possible.
   1. 1. AC60-70 is measured by penetration grade system specified in ASTM D5, which means that the asphalt binder is in the range of 60-70 penetration values. In Thailand, we encounter mostly warm and rainy season, the temperature shows high almost all year. So the PG is shown only high temperature at page 6 line 155.
2. It should be mentioned the reason why there is difference between TSR in IDT and that in POTS (e.g. some equations to show the difference). 
   1. 1. Please see in summary of findings #7.
3. It seems the two tests in wet condition were not at same temperature (one is 60C, one is 64C).
   1. 1. The POTS test in this study is the preliminary test. The author tried 60C, but the strength cannot be determined as the stiffness of POTS is too high which the POTS cannot be read.
4. If the TSR results passes the specfication, how about other test results (cracking and rutting) for the same material combination (e.g. bagasse or coconut peat)? Can they still pass the tests?
   1. 1. In this study, we show only the study of moisture damage resistance. The further study on other failure testing needs to be confirmed that the bagasse and coconut peat can be effective material to replace the aggregate fillers.
5. It may be worthy to discuss some factors and more materials to check the the usefulness of POTS.
   1. 1. We put in the summary of findings #7 and 8 and recommendation sections.

• • • The TSR values for POTS test are lower than those of ITS test approximately 0.65 times. The reason can be attributed by the different curing temperature, curing time, and concept of testing. Therefore, to establish the TSR specification of POTS test, different scenarios of curing temperature, curing time and asphalt mixtures.
    • Results show that the TSR presented in the POTS test for asphalt mixture which show the mixtures with granite filler give lower TSR than those with limestone filler. This result can be comparable to the stripping point presented in Hamburg Wheel Tracking Test (HWT) which showed the same trend as TSR in the POTS test
  • Recommendation
    • ....Also, the POTS is a promising tool of measuring direct tensile strength of asphalt mixture to determine moisture damage resistance with better simulating to field behavior, lower cost of equipment, and light weight. These reasons the industry can benefit from adopting this test rather than the heavy and costly equipment. However, it is necessary to establish the specification by determining more POTS tests.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors,
your paper is interesting. The field of alternative, while simultaneously economically and environmentally friendly, materials for asphalt mixtures is currently highly relevant. My major suggestion is to add a comparison of your results to other results introducing other alternative materials for asphalt mixtures. Along with this comparison, it is necessary to provide how practically will the industry benefit by using alternative material that you suggest. Other from that, I have some minor suggestions for your paper:
1) the title is too long and needs to be more representative of the paper.
2) equations 1 and 2 are a bit blur, it seems as a pasted figures.
3) figures, in general, are of low quality (e.g. in figure 1 captions, figures presenting common laboratory equipment is not something that is necessarily needed to present, figure 4 b is trivial, figures 6, 7 and 8 seem like snapshots from an old textbook,  etc.).
4) did you analyzed other curve fittings other from the linear correlation? I must admit that the ideal linear relation is surprising to me.
Kind regards

Author Response

Thank you very much for your reviewing. Here are the response for your comments:

To add a comparison of your results to other results introducing other alternative materials for asphalt mixtures.

• Please see in the last bullet of summary of findings and conclusion parts.

1) the title is too long and needs to be more representative of the paper.

• we reduce it to be "Evaluation of Using Natural Fillers to Improve Moisture Damage Resistance and the Use of Pull-off Tensile Test in Determining Moisture Damage Resistance in Asphalt Mixture"

2) equations 1 and 2 are a bit blur, it seems as a pasted figures.

• Edited, Please see the Eq. 1 and 2

3) figures, in general, are of low quality (e.g. in figure 1 captions, figures presenting common laboratory equipment is not something that is necessarily needed to present, figure 4 b is trivial, figures 6, 7 and 8 seem like snapshots from an old textbook,  etc.).

• Edited, Please see the attachment

4) did you analyzed other curve fittings other from the linear correlation? I must admit that the ideal linear relation is surprising to me. 

• In this study, we have not analyzed any curve fittings other than linear as we would like to show the preliminary test which the number of test in this study is quite small. The further study needs to be determined more tests to confirm if the relationship of these two methods is linear or other curve fittings. We put the recommendation in the summary of findings #6. Thanks for your suggestion

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Dear authors,
thank you for acknowledging my suggestions. The importance of publishing the preliminary findings sometimes puts a shade and expectations for the final results, please keep this in mind. Otherwise, I'm looking forward to seeing the results on a more significant number of tests.
Kind regards