Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 Reviewing report

Manuscript entitled “Recycled PET as a Modular System for Coastal Slope Stabilisation: A Preliminary Numerical Climate-Adaptation Approach in Chucuito, Callao “

1. You need to write the whole name of the abbraviations in the first mentioned place. For example “FEA–CFD”

Please revise all

2. Some paragraphs need to be combined as one paragraph. For example lines :70-115, 43-69.
3. Line 122, is that bracket right “[15–18])”?
4. The equations need references
5. You need to make figure for stability analysis of the unreinforced slope.

For help, see this : Numerical Investigation of Slope Stabilization Using Recycled Plastic Pins in Yazoo Clay

Mohammad Sadik Khan

 

GOOD LUCK

Author Response

Dear Reviewer, kindly refer to the attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper provides an interesting approach for integrating recycled PET waste into coastal protection structures (modular unit). It investigates the performance of proposed modular unit-based material composition. The introduction is supported by relevant literature, problem statement, and research gap. The applied methodology is presented in detail, and the results and discussion are well investigated.

A critical observation: the paper is presented as a research article; its contribution is primarily at the proof-of-concept and screening level (as the authors also stated and was reflected in the many detected limitations, assumptions, and unvalidated stages adopted throughout the study). However, the limitations of the research are highlighted and clearly presented/discussed, further discussion could be added regarding the expected long-term durability of the proposed unit compared with conventional coastal structures (particularly in terms of service life, maintenance requirements, and resistance to marine exposure conditions), implementation and economic feasibility, etc.

Respecting Table 1: consolidated physical–mechanical properties used as input for the study, additional justification for the utilized values is recommended particularly for PET–concrete mix (10/90).

The authors provided a justification for using SolidWorks Flow Simulation; however, references to previous studies (comparative studies) that have applied the same software are recommended to enhance the paper outputs.

The last paragraph of the materials and methods, page 12 from line 494 to line 498, the author states “With this structure, the Materials and Methods section is closed in terms of traceability, reproducibility, and conceptual coherence: a single phenomenon associated with wave impact on coastal slopes is defined, along with a single load formulation, a single damping parametrization, a parallel, one way comparative FEA CFD evaluation scheme, and a single representation of the PET concrete composite as an equivalent solid.” It appears to be more biased interpretative than methodological. Removing this paragraph is recommended.

How do slope (angle), roughness, porosity and run-up height individually contribute to overtopping reduction? How CFD results in that term was validated, for instance why EurOtop formulations not used.

Respecting the utilized hollow PET–concrete modular unit, are the authors considered/ simulated the interaction and stability of adjacent units under wave loading (Interlocking or connection mechanisms) in the proposed modular system?

Author Response

Dear Reviewer, kindly refer to the attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1.The PET-concrete composite is treated as an equivalent isotropic solid, ignoring the bonding, debonding, and local stress concentration behaviors between PET flakes and the cement matrix. This simplification may underestimate the risk of local failure. It is recommended to supplement an explanation of the impact of this simplification on the results.

2.The conclusion of "no overtopping" for θ ≤ 53° shown in Figure 3 is derived based on the equivalent roughness boundary condition. Since this boundary condition does not resolve the pore flow between units and the gap flow between riprap stones, does this conclusion require further validation through experimental models?

3.The color bar ranges are inconsistent across the six velocity field subplots in Figure 3. Why are different color bar configurations adopted for the θ = 60° and θ = 45° cases? Will this mislead readers in making direct comparisons of the velocity fields under different working conditions?

4.The velocity range of the hollow module under the 45° working condition is reported as "0–0.5 m/s" in Table 3, which is explained by the fact that values below the extraction threshold are recorded as 0. However, how was this threshold selected? If the threshold were changed to 0.2 m/s or 0.8 m/s, would the conclusion (e.g., "hollow modules outperform riprap") still hold?

5.The equivalent peak flow velocity v=10 m/s used in this paper is an overly single parameter value. It is recommended to add a sensitivity analysis for different equivalent peak flow velocities.

6.Please supplement the specific values, quantitative derivation processes, and corresponding literature references for the equivalent roughness coefficients of the two revetment forms, and conduct a sensitivity analysis of the roughness parameters.

7.It is recommended to supplement at least one set of experimental data on the interfacial bond shear strength of PET-concrete with the same mix proportion, or explicitly state the impact of the absence of this parameter on the results.

8.It is recommended to uniformly adjust the format of the text, formulas, and references in the paper in accordance with the journal's typesetting requirements. In addition, the readability of Figure 1 and Figure 3 is poor; please revise and improve them accordingly.

Author Response

Dear Reviewer, kindly refer to the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

1. Please remove this "–" in the abstract. The same line s 46, 47. Please revise all manuscript
2. Again,  Some paragraphs need to be combined as one paragraph. For example lines: 70–115, 43–69.
3. This number must be inside the brackets "(e.g., Gravina et al.) [21]"
4. Please look to equation 2, whats u mean ?
5. Whats the meaning of CAV in equation 1?
6. Please write the meaning of T inside equation 3
7. Inside table 4 please correct O here "EurOtop"
8. PLease look to lines 604-605

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The revised version is obviously improved, and all my comments were addressed 

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

1. Inside reference 42, the equation 2 is without the brackets. Why you added brackets ?
2. Please combine lines 77-139
3. This "𝑣(𝑡)" need to be defined in equation 1
4.  

Author Response

Dear Reviewer, kindly refer to the attached file.

Author Response File: Author Response.pdf