Adhesive and Cohesive Cracking Analysis of Asphalt Mastics in Contact with Steel Substrates Using an Energy-Based Crack Initiation Criterion

Round 1

Reviewer 1 Report

In this study, the adhesive and cohesive cracking of bitumen–filler mastics on stainless steel plates were investigated using a uniaxial tensile test at a constant strain rate. An energy-based crack initiation criterion was developed to incorporate the impacts of the mechanical properties and surface free energy on adhesive and cohesive cracking. In general, this is a very interesting paper. Below are my comments.

1. The adhesion loss can happen between big aggregate and asphalt and between fillers and asphalt. The two scenarios may have different implications on the overall material properties. The literature review may include more information on it.

2. The literature review should have more description of stripping which is highly related to the moisture damage of asphalt mixtures. The recently published papers regarding the moisture damage mechanism, stripping, the influence of asphalt aging (investigated by surface free energy method) should be reviewed. ("Moisture Damage Mechanism and Thermodynamic Properties of Hot-Mix Asphalt under Aging Conditions. ACS Sustainable Chemistry & Engineering, 10(45), pp.14865-14887.")

2. How are those equations related to your experimental results? The readability can be improved.

3. Is there any energy loss when strain energy converts to surface energy? Is there energy related to the local recovery of deformation after cracking.

4. The conclusion part is lengthy and should be shortened. The scientific value of this paper should be explain in detail.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript presents an interesting topic. However the reviewer has the following comments to improve the quality of the manuscript.

Abstract should be improved and present quantitive results.

 

Title should be modified.

Literature review should be extended. Some suggested studies:

https://doi.org/10.1080/14680629.2020.1826347

https://doi.org/10.1007/s41062-018-0190-z

https://doi.org/10.1007/s41062-019-0230-3

 

The authors should enhance the discussion section by comparing the findings of this studies with previous studies (the first suggested study can be used for comparison)

A recommendation for the practioners should be lighted 

limitations should be discussed 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Generally minor comments:

1. were Any stress dependent tests were performed?

2. How the thickness and dia was ensured? were the samples trimmed like bitumen? Adding photo will help.

 

3. Adhesion to preheated plate: does it cause a weak spot? how many failures at the joint? some photo of the failed samples will help to understand.

4. as shown,  mastic fracture is independent of strain rate. caveats of the tests should be clearly stated. 

 

5. Correlation between surface free energy and crack size was not discussed well/ line 419 -420 can be discussed in detail as they show meaningful implication

6. Works done by Bhasin et al on poker chip geometry was not cited.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This paper has been revised based on the comment and should be ready for publication.

Reviewer 2 Report

The authors addressed the reviewer comments.