Study on Flexural Strength of Interface between Full Lightweight Ceramsite Concrete and Ordinary Concrete
Round 1
Reviewer 1 Report
The article is based on the results of experimental tests, which is a valuable advantage of the publication. I suggest the authors in the introduction to mention the complex state of stress that occurs at the interface between old and new concrete during the bending test - part of the surface of the adhesion joint is loaded to peel (the worst case of adhesion joint) while the rest of the joint is in compression.
Author Response
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Reviewer 2 Report
The authors have presented an experimental study to explore the different factors affecting the flexural strength of interface between full lightweight ceramsite concrete and ordinary concrete. The experimental data was presented and a formula to depict the flexural strength was proposed. However, the data presented in this paper is quite less to form a sound scientific research paper. The experimental data is less with missing the main parameters like compressive strength, slump, air content of both the concretes. IN addition, out of 14 groups, only three had varied interfacial roughness (so to categorize this a studied parameter is not justified. In addition the same observation was made for the curing age as well. Finally, to propose a formula, an ample data set is required to train the model and finally, justidy the proposed model with another independent set of data, which in your case will be other light wight concretes. In review’s opinion, this study needs an overall improvement by addition of studied parameters and including enough data set for modelling/proposing the equation.
Author Response
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Reviewer 3 Report
Review Report
Manuscript ID: coatings-2501092
Manuscript Title: Study on Flexural Strength of Interface Between Full Light-weight Ceramsite Concrete and Ordinary Concrete
The study analyzed the flexural strength of new lightweight ceramsite concrete used in repairing existing concrete structures. The research examined factors such as interfacial roughness, interfacial agent type, and concrete curing age to determine their impact on the flexural performance of the bonding surface. The findings indicated that repairing ordinary concrete with lightweight ceramsite concrete could achieve approximately 75% of the flexural strength of the
original structure. Interfacial roughness should be controlled within a reasonable range to avoid microcracks and maintain the integrity of the existing concrete. Coating interfacial agents, particularly epoxy resin, were effective in improving the flexural strength of the interface. The curing age of the existing concrete negatively affected the flexural strength until it stabilized after 28 days. The study concluded by presenting a formula to calculate the flexural strength of the interface between lightweight ceramsite concrete and ordinary concrete, considering the three influencing factors. The findings aimed to provide scientific guidance for reinforcing concrete projects with lightweight ceramsite concrete.
The topic is interesting and has practical importance and surely falls within the scopes of the journal. The manuscript is generally well-written and organized. The adopted mythology and developed models are explained clearly, the attained results are presented suitably, and the provided conclusions are completely supported by the attained results. In depth discussion and analysis are provided on the attained results as well. The literature review section can benefit from improvement. A proofreading to modify limited existing language errors is suggested.
Overall, I would like to suggest acceptance of the manuscript after considering the following minor modifications:
- Please add some of the most important quantitative findings of the study to the abstract.
- It is strongly suggested to provide more explanation regarding the previous studies on
ceramsite concrete in the introduction section.
- Please replace “indicators” with “characteristics” in line 87. The same comment applies to
the captions of tables 1 to 5.
- English language of the manuscript can benefit from a proofreading by a native speaker.
Some suggestions are presented in the attached report.
Author Response
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Reviewer 4 Report
The reviewer thanks the authors and editors for the opportunity to review the manuscript. The article discusses the study on flexural strength of interface between full lightweight ceramsite concrete and ordinary concrete.
Comments:
1) The test results presented in the manuscript seem interesting. However, the flexural strength results do not have significant differences, which may suggest measurement error. How can the authors be sure that similar results can be obtained on similar tests?
2) The authors refer mainly to roughness. However, strength parameters are also mainly influenced by structure and mineral composition. The authors should refer to this aspect more extensively.
Author Response
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Reviewer 5 Report
The paper shows potential; however, there are significant methodological errors concerning data processing and paper presentation, necessitating a major revision.
To improve the paper's presentation, please merge Tables 1, 2, and 3. Furthermore, for Figures 6 and 7, it is insufficient to use only four points for fitting. Please remove the fitting equation and instead provide a table with related content for the experimental results, acknowledging the inherent uncertainties and parameter variability that make fitting with only four points unacceptable.
It is important to conduct more tests to calibrate new formulas rather than solely validating existing ones or suggesting possible improvements. Therefore, additional tests are needed.
Table 9 contains an excessive amount of data. As the metrics are not commented upon, they are unnecessary. Please reduce the table to include only the most significant metrics, approximately half the current size.
Additionally, it is essential to address the issue of scale effect by referencing the following paper, which investigates how the size of the bonding surface affects strength:
Cucuzza, R., Aloisio, A., Accornero, F., Marinelli, A., Bassoli, E., & Marano, G. C. (2023). Size-scale effects and modelling issues of fibre-reinforced concrete beams. Construction and Building Materials, 392, 131727.
Consider discussing whether the bending of two concrete samples bonded together is a realistic situation and provide relevant comments.
To enhance the state of the art, please refer to the following papers:
Manawadu, A., Qiao, P., & Wen, H. (2023). Characterization of substrate-to-overlay interface bond in concrete repairs: A review. Construction and Building Materials, 373, 130828.
Afandi, M. E., Yehia, S., Landolsi, T., Qaddoumi, N., & Elchalakani, M. (2023). Concrete-to-concrete bond Strength: A review. Construction and Building Materials, 363, 129820.
Additionally, please include figures illustrating the different bonding techniques.
Author Response
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Round 2
Reviewer 2 Report
Thank you for your response. However, the revised manuscript do not represent the significant changes made to the original manuscript. Lightweight concrete is characterized by its density and strength. Huge dataset is available for this kind of concrete incorporating different materials. The material used in this study can be compared with other similar/different materials used to formulate lightweight concrete. In addition, please add strong scientific discussion to increase the value of the paper.
Author Response
Dear Reviewer:
Thank you for your valuable suggestions. We have carefully read through the comments and made proper revisions. Our responses to your questions are listed below.
- Huge dataset is available for this kind of concrete incorporating different materials. The material used in this study can be compared with other similar/different materials used to formulate lightweight concrete. In addition, please add strong scientific discussion to increase the value of the paper.
Response: Thank you for your valuable suggestion. A review of the literature revealed a degree of correlation between flexural and compressive strengths, and some scholars also used the compressive strength in the establishment of the equation. The original formula was partially modified and highlight them in orange color. The literature review is given below. And we have incorporated your suggestions in the article and highlighted them in orange (reference section has been added and highlighted in orange).
Suda, V.B.R.; Paul, S. Priyatham.; Relationship between compressive, split tensile and flexural strengths of ternary blended concrete. Mater. Today. 2022, 65, 1112-1119.
Huang, H.; Yuan, Y.; Zhang, W.; et al. Bond behavior between lightweight aggregate concrete and normal weight concrete based on splitting-tensile test. Constr. Build. Mater. 2019, 209, 306-314.
Wu, E.; Ayinde, O.O.; Zhou, G. Shear behaviour and constitutive model of old-to-new concrete interface with single roughness tooth: Experimental and numerical investigation. Structures. 2023, 53, 1196-1214.
Sincerely yours,
Reviewer 5 Report
Accept
Author Response
Thank you for your comments.
Round 3
Reviewer 2 Report
Thank you for your responses.
