PONE-D-25-02028 Research on repairing materials and techniques of cracks in Kaifeng earth wall PLOS ONE

Dear Dr. 岳,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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We look forward to receiving your revised manuscript.

Kind regards,

Gobinath Ravindran

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: No

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript presents a valuable study on the repair of cracks in Kaifeng's earth walls using various materials, but there are several areas that require significant improvement before publication. One major concern is the lack of a clear justification for the research’s novelty. While the introduction provides a detailed background on the deterioration mechanisms of earth walls (Page 2, Lines 10–38), it does not sufficiently differentiate this study from previous works. Many references (e.g., Cui et al. [3,4], Zhang et al. [8,9]) discuss similar approaches using strengthening agents, but the authors fail to explicitly state how their methodology or findings contribute to advancing the field. The manuscript would benefit from a stronger argument on what makes this study unique, such as the combination of repair materials or the specific application of the efficacy coefficient method.

The methodology section lacks crucial details that would allow replication. For example, while the authors describe the preparation of soil samples and repair materials (Page 6, Lines 12–40), they do not provide sufficient information about the curing conditions, environmental parameters, or the exact procedure for mixing and applying the materials. Additionally, while the freeze-thaw cycle test is mentioned (Page 12, Lines 4–18), the manuscript does not specify the temperature range, cycle duration, or the reasoning behind the number of cycles chosen. Given that freeze-thaw durability is a key performance indicator for long-term crack repair, these missing details significantly weaken the reliability of the results. The authors should provide explicit temperature settings and cycle descriptions, referencing standard testing protocols where applicable.

The discussion of results lacks depth in terms of explaining the chemical and physical interactions between repair materials and the soil. For instance, while the manuscript explains that sodium methylsilicate forms a hydrophobic film (Page 10, Lines 30–38), it does not explore whether this film affects the soil’s permeability or long-term stability. Additionally, the interaction between quicklime, urease, and urea in forming calcium carbonate (Page 7, Lines 20–38) is described, but the implications of this reaction on the material’s porosity and potential shrinkage are not addressed. Furthermore, no information is provided on possible secondary effects, such as efflorescence, which could impact the aesthetic and mechanical properties of the repaired cracks. A more detailed chemical discussion is needed to strengthen the conclusions.

There are several inconsistencies and grammatical errors throughout the manuscript. For instance, "methicosilicate" appears multiple times (Page 3, Line 20; Page 8, Line 5) but is likely meant to be "methylsilicate." Similarly, "waterborne polyurethane" and "water-based polyurethane" are used interchangeably (Page 3, Line 15; Page 9, Line 30), which could confuse readers. Terminology should be consistent throughout the paper. The abstract (Page 1, Lines 10–25) also contains awkward phrasing, such as "the repair material does a great job fixing the simulated crack," which should be revised for a more formal academic tone. Furthermore, certain sentences are overly informal, such as "this stuff is pretty strong" (Page 2, Line 14), which should be rewritten in a more precise scientific manner.

Figures and tables require improvements in clarity. Some figures, such as the particle gradation diagram (Page 7, Figure 1), lack clear axis labels, making it difficult to interpret trends. Tables summarizing experimental data should include statistical comparisons to highlight significant differences between groups. Additionally, some references in the bibliography appear incomplete or improperly formatted. For example, certain citations (e.g., Page 19, References [12,13]) lack full journal details and DOI links. Ensuring correct formatting and consistency across citations is essential for maintaining academic credibility.

Reviewer #2: I have gone through the manuscript and the topic is good. I have some recommendations that would help to improve the quality of the manuscript.

1. A graphical abstract should be included in the manuscript to make it more appealing.

2. The abstract is too vague and does not summarize key findings properly.

3. The manuscript addresses an important topic, but its novelty needs to be clearly stated.

4. There is a lack of clear objectives; these should be explicitly stated.

5. There are a lot of headings in the manuscript, which does not make sense. These should be removed, and flow and coherence should be maintained.

6. The results are not well-organized and should be presented more systematically.

7. The authors should provide a stronger closing statement.

8. The aesthetics could be improved in all of the images and graphs.

9. All the headings should be revised and made more TO THE POINT and brief.

10. All the figures need revision. All the figures have the potential that a lot of information may be included in them. They should be made more informatically appealing with more attention to detail.

11. The design of experiments (DOE) should be more clearly explained.

12. The conclusion section should be more robust and clearly state the findings of the results obtained. Future scope and work should be included.

13. The Results and Discussion section should be added and populated as necessary.

14. The limitations and the future potentials of the study are not sufficiently addressed or acknowledged.

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Reviewer #1: Yes: Muhammad Usama Zaheer

Reviewer #2: No

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Attachments

Attachment

Submitted filename: Reviewer Comments for Manuscript.pdf

PONE-D-25-02028R1 Study on Repair Materials and Technologies for Addressing Crack-Related Damage in the Earthen City Wall of Kaifeng PLOS ONE

Dear Dr. 岳,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.   Your manuscript has been assessed by two reviewers, who both raise points and concerns to address. Please give these points careful consideration when preparing your revised manuscript and point-by-point response document.

Please submit your revised manuscript by Oct 24 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Dr Jason Morgan

Staff Editor

PLOS ONE

Journal Requirements:

If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. 

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #3: No

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #3: No

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: No

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #3: No

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript presents an experimental study on repair materials and technologies for addressing crack-related damage in the Kaifeng earthen city wall. The topic is relevant and of practical importance to cultural heritage conservation. The experimental program is broad, testing 27 combinations of materials under multiple performance indicators, and the findings have practical significance for field applications. However, several issues should be addressed before the manuscript can be considered suitable for publication.

Language and Readability

The manuscript requires thorough English editing to correct grammatical errors, improve clarity, and reduce repetition. Several “Error! Reference source not found.” placeholders remain in the text and must be fixed. Improving the overall readability will significantly strengthen the manuscript’s presentation.

Novelty and Positioning

While the experimental program is systematic, the novelty compared to existing studies is not strongly emphasized. Many of the repair materials (quicklime, sodium methylsilicate, polyurethane, styrene-acrylic emulsion) and techniques (EICP/MICP) have already been studied in the context of soil stabilization and conservation. The authors should clearly highlight:

What specific research gap this study addresses.

How the work differs from and advances beyond prior studies.

Whether the innovation lies in the optimization of material ratios, the multi-indicator evaluation method, or the integration of hydraulic and mechanical performance metrics.

A deeper comparison with recent international literature is recommended.

Figures and Tables

Several figures and tables are of low quality, unclear, or missing proper references. All figures should be redrawn at higher resolution with consistent labeling. Broken cross-references must be corrected. Ensure that captions are detailed enough to allow standalone interpretation.

Statistical Analysis and Rigor

The results are largely presented as single values without error bars, standard deviations, or information on replicates. For a journal such as PLOS ONE, statistical robustness is essential. Please clarify the number of replicates for each test and include appropriate measures of variability. If possible, apply statistical tests (e.g., ANOVA) to support claims of significant differences.

Discussion Section

The discussion is mainly descriptive. It should go beyond reporting test outcomes and provide deeper insights into why certain combinations performed better. For example, what mechanisms explain the superior performance of 7.5% quicklime + 7% sodium methylsilicate? How do these results align with or contradict existing studies? The authors should also discuss limitations (e.g., scale effects, laboratory vs. field conditions) and the potential implications for conservation practices.

Reviewer #3: Recommendations for Improvement

1. Improve Clarity and Structure:

o Revise the introduction to clearly state the research problem, objectives, and the specific gap this study addresses compared to existing literature.

o Organize the manuscript into well-defined sections: Introduction, Literature Review, Methodology, Results, Discussion, and Conclusion. Ensure each section flows logically and avoids redundancy.

o Include a graphical abstract, as suggested by Reviewer 2, to provide a visual summary of the study's key findings and methodology.

2. Enhance Methodological Details:

o Provide a detailed explanation of the DOE, including the rationale for selecting specific concentrations of quicklime and waterproofing agents. Justify the choice of 27 groups and the criteria for material selection.

o Clarify the efficacy coefficient method by providing the mathematical formulation, assumptions, and how weighting coefficients were determined.

o Include a section on quality control measures during sample preparation and testing to ensure reproducibility.

3. Improve Data Presentation:

o Ensure all tables and figures are complete, with clear captions, axis labels, and statistical comparisons (e.g., ANOVA or t-tests) to validate significant differences between groups.

o Revise incomplete or poorly formatted tables (e.g., Table 5) and figures (e.g., particle gradation diagram). Provide a summary table comparing the performance of all 27 groups across the tested indicators.

o Include error bars or confidence intervals in graphical representations to indicate data variability.

4. Address Environmental Factors:

o Expand the discussion to include the coupled effects of temperature fluctuations, humidity, and groundwater dynamics, as suggested already. Consider conducting additional experiments or referencing relevant studies to address these factors.

o Provide a more detailed explanation of how the freeze-thaw cycle test simulates real-world conditions in Kaifeng.

5. Correct Formatting and Language:

o Thoroughly proofread the manuscript to correct grammatical errors, awkward phrasing, and OCR-related issues (e.g., "5.5.5.5" or "$\mathrm{J} \mathrm{J} \mathrm{J}$").

o Ensure consistent formatting of chemical names (e.g., "styrene-acrylic emulsion" instead of "styrene-acylle") and equations. Verify that all mathematical expressions are correctly rendered.

o Complete and standardize the reference list, ensuring all citations include necessary details (e.g., DOIs where available).

Specific Comments

• Abstract: If a graphical abstract has been added , ensure it is clear and visually appealing. The written abstract should concisely summarize the study's objectives, methods, key findings (e.g., 3.9% water absorption for the 5% sodium methylsilicate + 7.5% quicklime group), and implications.

• Introduction: Strengthen the literature review by citing more recent studies to contextualize the research gap.

• Methodology : Provide a flowchart or diagram to illustrate the experimental workflow, including sample preparation, testing procedures, and data analysis.

• Results : The claim of a 3.9% water absorption rate is significant but needs statistical validation. Discuss why sodium methylsilicate outperforms other waterproofing agents in greater detail.

• Discussion : Elaborate on the practical challenges of applying these repair materials in situ, such as cost, scalability, and compatibility with existing structures.

• References: Ensure all references (e.g., [1], [25], [40]) are complete and follow the journal's formatting guidelines.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: Yes: amirbahram arabahmadi

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Attachments

Attachment

Submitted filename: review.docx

Study on Repair Materials and Technologies for Addressing Crack-Related Damage in the Earthen City Wall of Kaifeng

PONE-D-25-02028R2

Dear Dr. 岳,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Hailing Ma

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: