Investigating the Potential of High-Density Polyethylene and Nano Clay Asphalt-Modified Binders to Enhance the Rutting Resistance of Asphalt Mixture

Round 1

Reviewer 1 Report

The authors pointed to a change in the high-temperature parameters of the asphalt. The increase in stiffness resulted in a decrease in creep. This effect could also be achieved by using harder asphalt.  The positive effect of the modifier should be proven over the entire range of use. The modifier should improve creep resistance while improving (or not changing) in low temperature resistance. Then the effectiveness of the modifier is greatest.

 

Major and secondary mistakes

Please add space between the numbers and units

Figures 6, 7 and 8 lack uncertainty. Note that Penetration Index (PI) depends on penetration and softening temperature. So the uncertainty of PI will be correspondingly larger.

Line 120 (table 1) Penetration, dmm ?

Line 123 information needed where this data came from

Line 127 max and min limit from which standards this data

Line 131 Desity unit should be Mg/m3 or g/cm3

Line 132 is this a table? if so describe it correctly

Line 167 Why such a "hole" is formed in the relief phase, please explain this phenomenon. Shouldn't this graph look like a typical Burgers model?

Line 273 (Table5) Too much precision (MPa), is it really your precision? Stability in kg?

Line 279 The values of m and a should be described in detail in the theoretical part

Line 304 (Fig 15) value of 100 should be on the other side of the equation

Line 326 (Fig 16) value of 100 should be on the other side of the equation

Line 329 (Fig 16) value of 100 should be on the other side of the equation, proposes to reject the outlier, softening temperature instead of softening (caption)

Line 335 (Fig 17) value of 100 should be on the other side of the equation

Line 337 (Fig 17) value of 100 should be on the other side of the equation,

Line 366 (Fig 19) proposes to reject the outlier

 

Regards

Author Response

Thanks a lot for your valuable comments

Comment: Figures 6, 7 and 8 lack uncertainty. Note that Penetration Index (PI) depends on penetration and softening temperature. So, the uncertainty of PI will be correspondingly larger.

Reply: the results are revised, and no issue has been found. The result variation of the three tests is very low (less than 10%)

 

 

Comment: Line 120 (table 1) Penetration, dmm?

Reply: the issue is corrected to be “mm”

 

Comment: Line 123 information needed where this data came from

Reply: figure 2, shown at line 123, reveals the result of the scanning electron microscopy. The test procedure and this result are discussed in section 2.1

 

Comment: Line 127 max and min limit from which standards this data

Reply: the source of those standards are clarified in Section 2.2

 

Comment: Line 131 Desity unit should be Mg/m3 or g/cm3

Reply: the unit is changed to be “g/cm3”

 

Comment: Line 132 is this a table? if so describe it correctly

Reply: table 4 is modified to clarify the source of specifications inside instead of the notes underneath

 

Comment: Line 167 Why such a "hole" is formed in the relief phase, please explain this phenomenon.

Reply: this comment may intend the little increase in the strain after the strain recovery. This phenomena may be due to the rearrangement of the stress concentrations inside the sample by the change from loading to the unloading state.

 

Comment: Line 273 (Table5) Too much precision (MPa), is it really your precision? Stability in kg?

Reply: the authors can not figure out any abnormal results in this table

 

Comment: Line 279 The values of m and a should be described in detail in the theoretical part

Reply: those two factors are presented and explained in section 3.2

 

Comments: Line 304 (Fig 15) value of 100 should be on the other side of the equation

Line 326 (Fig 16) value of 100 should be on the other side of the equation

Line 329 (Fig 16) value of 100 should be on the other side of the equation, proposes to reject the outlier, softening temperature instead of softening (caption)

Line 335 (Fig 17) value of 100 should be on the other side of the equation

Line 337 (Fig 17) value of 100 should be on the other side of the equation,

Line 366 (Fig 19) proposes to reject the outlier

Reply: the equations in those figures are corrected. The authors decided not to reject the outliers in any model in this study as there is no scientific reason proposes the removal of the outliers

Reviewer 2 Report

From a scientific point of view, this article does not provide enough information to support the conclusions.

The amount of experimental data is not enough, and the fitting formula in this paper has low accuracy.

Moderate editing of English language required

Author Response

Thanks for your valuable comments

Comment: From a scientific point of view, this article does not provide enough information to support the conclusions.

Reply: the rutting resistance of the asphalt mixture of those two modifiers is the objective of this study. To this end, the conclusions are modified to be more focused on the study scope.

 

Comment: The amount of experimental data is not enough, and the fitting formula in this paper has low accuracy.

Reply: the rutting performance of the two asphalt mixture types is the focus of the study. To this end, Multiple mixture characteristics, such as stiffness, strain underloading, deformation susceptibility with time, and elasticity, were tested and evaluated through the creep test. The test results, including all indicators, emphasized clearly the high rutting resistance of the targeted asphalt mixture types. Thus, the authors do not believe that any further experimental work may lead to different conclusions regarding the rutting performance. Most regression models have R² higher than 0.5, while only one predictor is considered in the model. In other words, one independent variable representing binder basic property (penetration or softening point) can explain over 50% of the variation in the asphalt mixture performance. Moreover, besides the correlation coefficient, two statistical tests were conducted to ensure the significance of the model. Only models with significant correlation according to the statistical analysis were considered in this study. Although the uncontrolled variability in the microstructure of the asphalt mixture at the macro scale, the regression models succeeded to prove the crucial role of the binder type in the mixture performance. Thus, the authors believe in the scientific meaning and importance of the derived regression models.

Reviewer 3 Report

More information on the reason for choosing high-density polyethylene and nano Clay to enhance the Rutting Resistance of asphalt Mixture is need.

Moderate editing of English language required

Author Response

Thanks a lot for your valuable comment

More information on the reason for choosing high-density polyethylene and nano Clay to enhance the Rutting Resistance of asphalt Mixture is need.

Reply: two subsections are added (1.2 and 1.3) to clarify the objective and novelty of the study

Reviewer 4 Report

Please see the attachment.

Comments for author File: Comments.pdf

Author Response

Thanks for your valuable comments

Comment: The flowchart must be included in the text

Reply: The flowchart was added

 

Comment: It should be stated where the binder and aggregate components came from

Reply: multiple sentences are added in sections 2.1 and 2.2 to clarify the material source.

 

Comment: Where was the experimental research carried out?

Reply: Sohag university in Egypt

 

Comment: The standard limitations should be included in Tables 1 and 2.

Reply: The standard limitations were included in Tables 1, but Table is Data sheet and It has no specific limits.

 

Comment: - The physical properties of the aggregate should be indicated - Filler material characteristics must be provided

Reply: the basic properties of the aggregate are added in a separated new table (see Table 4)

 

Comment: Abbreviations must be defined. (AM, SEM, and so forth.)

Reply: the abbreviations in this manuscript are very limited. Each abbreviation is defined in its first appear

 

Comment: What's the difference between HDPE and HPDE?

Reply: it is a mistake . it should be HDPE. The mistake is solved and the abbreviation is unified to be HDPE

 

Comment: The description in Figure 4 should be changed to aggregate gradation

Reply: the figure caption is changed to “aggregate gradation”

 

Comment: The source of the modifiers should be explained

Reply: the source of modifiers is clarified in section 2.1

 

Comment: Units should be added (Figure 5 b).

Reply: this figure shows the strain propagation. The strain is dimensionless

 

Comment: The RV and penetration values of 3% NC and 4% NC should be reviewed

Reply: the results are revised, and no issue is found

 

Comment: Don't 4% HDPE and 4% NC have the highest a value, while 2% HDPE and 1% NC have the highest m value in Figure 14?

Reply: 4% HDPE has the lowest value according to figure 14. The explanation for the results were provided in the fifth paragraph of section 4.2.

 

Comment: Why are the function equations in Figures 16-17-18 presented in linear form? (The R2 values are poor). Because of the variations in the numbers, wouldn't it be easier to think of it as a 2nd or 3rd order function equation in terms of high correlation?

Reply: Most regression models have R² higher than 0.5, while only one predictor is considered in the model. In other words, one independent variable representing binder basic property (penetration or softening point) can explain over 50% of the variation in the asphalt mixture performance. Moreover, besides the correlation coefficient, two statistical tests were conducted to ensure the significance of the model. Only models with significant correlation according to the statistical analysis were considered in this study. Although the uncontrolled variability in the microstructure of the asphalt mixture at the macro scale, the regression models succeeded to prove the crucial role of the binder type in the mixture performance. Thus, the authors believe in the scientific meaning and importance of the derived regression models.

 

 

Comment: The third item in the conclusion should be rewritten. The results section should include SEM and XRD testing.

Reply: the conclusion part is changed. XRD and SEM tests were used to characterize the basic property of the raw materials only. So, those two tests have no vital contribution in the study scope. Accordingly, their results were added only in the sections describing the basic characteristics of the materials.

 

Reviewer 5 Report

Article is interesting. Few observations are given below;

 

1. Abstract need revision with some quantitative results.

2. Some more studies are required in the introduction section to further highlight the importance of this study.

Rashid, A. S. A., Shirazi, M. G., Mohamad, H., & Sahdi, F. (2017). Bearing capacity of sandy soil treated by Kenaf fibre geotextile. Environmental Earth Sciences, 76, 1-6.

Jusoh, S. N., Mohamad, H., Marto, A., Yunus, N. M., & Kasim, F. (2015). Segment’s joint in precast tunnel lining design. J Teknol, 77(11), 91-98.

 

Namazi, E., Mohamad, H., Jorat, M. E., & Hajihassani, M. (2011). Investigation on the effects of twin tunnel excavations beneath a road underpass. Electronic Journal of Geotechnical Engineering, 16(1), 1-8.

3.  The quality of figures is poor.

4. Authors must summarized results in more systematic way with reference to the previous studies.

5. Further, the observed failure modes are not discussed with reasons and also not compared with the existing studies. It is imported to show real pictures of test samples along with proper discussion.

6. Also, Conclusions are too limited to proof the significant outcome of this study.

 

 

 

 

 

Minor editing of English language required.

Author Response

Thanks for your comments

Comment: 1. Abstract need revision with some quantitative results.

Reply: the abstract is rewritten

 

Comment: 2. Some more studies are required in the introduction section to further highlight the importance of this study

Reply: the authors found those references are not even related to pavement/asphalt engineering. Thus, the authors decided not to add them

 

Comment: 3.  The quality of figures is poor

Reply: the figures are very clear and simple in showing the results and regression models. the authors do not think that the figures are with poor quality

 

Comment: 4. Authors must summarized results in more systematic way with reference to the previous studies.

Reply: references are added in the result part to support the discussion

 

Comment: 5. Further, the observed failure modes are not discussed with reasons and also not compared with the existing studies. It is imported to show real pictures of test samples along with proper discussion.

Reply: there are no distinct failure modes for the static creep test

 

Comment: 6. Also, Conclusions are too limited to proof the significant outcome of this study.

Reply: conclusions are rewritten to be more focused on the results related to the study scope

Reviewer 6 Report

Article entitled as "Investigating the Potential of High-density Polyethylene and

Nano Clay Asphalt Modified Binders to Enhance the Rutting

Resistance of Asphalt Mixture" discuss about application of nano clay in asphalt mixture. In order to raise the quality of manuscript authors are requested to address following comments 

 

1. In abstract: conclusion part is confusing. Rewrite it.

2. For a quality magazine, introduction should be minimum 2 pages. Introduction is not adequate

3. Research gap is not clear. Rewrite it

4. Make separate heading for novelty of research and research objectives

5. Include nomenclature for manuscript

6. Discuss about figures separately not in together form. For example in page 8. Section 4.1. paragraph start with figures 6, 7, 8

7. In results and discussion part, there is only one reference is found. Authors are requested to compare the scientific findings with previous studies

8. Most of correlation value R is less than 0.6. What is reason behind that? Is it necessary to draw correlation with such low value. Explain it proper references

9. Include units for figure 19

10. Include scope for future research in conclusion part

Dear Authors..

 

Moderate checking of language is required.

Author Response

Thanks for your valuable comments

Comment: In abstract: conclusion part is confusing. Rewrite 

Reply: the abstract is rewritten

 

Comment: For a quality magazine, introduction should be minimum 2 pages. Introduction is not adequate

Reply:  This magazine does not require a minimum number of pages for the introduction. Two subsections are added in the introduction part to well introduce for the study approach

 

 

Comment: Research gap is not clear. Rewrite it

Reply: Research gap was Rewritten.

 

 

 

Comment: Make separate heading for novelty of research and research objectives

Reply: separate heading for novelty of research and research objectives were added.

 

 

Comment: Discuss about figures separately not in together form. For example in page 8. Section 4.1. paragraph start with figures 6, 7, 8

Reply: those three figures present penetration, softening, and viscosity of asphalt binders, which are very basic characteristics. The authors believe that there is no need to discuss each of those basic properties separately.

 

Comment: In the results and discussion part, there is only one reference found. Authors are requested to compare the scientific findings with previous studies.

Reply: more references were added to compare the scientific findings with previous studies.

Comment: Most of correlation value R is less than 0.6. What is reason behind that? Is it necessary to draw correlation with such low value.

Reply: Most regression models have R² higher than 0.5, while only one predictor is considered in the model. In other words, one independent variable representing binder basic property (penetration or softening point) can explain over 50% of the variation in the asphalt mixture performance. Moreover, besides the correlation coefficient, two statistical tests were conducted to ensure the significance of the model. Only models with significant correlation according to the statistical analysis were considered in this study. Although the uncontrolled variability in the microstructure of the asphalt mixture at the macro scale, the regression models succeeded to prove the crucial role of the binder type in the mixture performance. Thus, the authors believe in the scientific meaning and importance of the derived regression models.

Comment: Include units for figure 19

Reply: this figure presents the prediction model for the strains in the asphalt mixture. As the strain is dimensionless, there are no dimensions to be written on the figure

 

Comment:  Include scope for future research in conclusion part

Reply: scope for future research was included in the conclusion part.

Round 2

Reviewer 1 Report

Comments similar to previous

Author Response

Thanks a lot for your valuable comments

the corrections are made accordingly and highlighted in the new version of the manuscript. if the corrections made are not sufficient, the authors welcome any further modifications.

Reviewer 4 Report

The authors performed modifications that were required after realizing what needed to be changed on the manuscript

Author Response

thanks a lot for your valuable comments

Round 3

Reviewer 1 Report

Best Regards

Author Response

Dear Reviewer

The authors have addressed all the comments.

Kind regards

Anmar