Study on the Constitutive Relationship between Ordinary Concrete and Nano-Titanium Dioxide-Modified Concrete at High Temperature
Round 1
Reviewer 1 Report
The manuscript "Study on the constitutive relationship between ordinary concrete and concrete modified with nano-titanium at high temperature" presents the comparison between mechanical tests and constitutive models of two different concrete formulas. The results show that the high-temperature modified concrete is in accordance with its intended purpose. Suggestions for improvement are presented below.
The manuscript is original and has merit, but needs improvement.
The introduction provides detailed information on the topic, but paragraph 2 is too long. Please split the text into two or more paragraphs.
Section 2: Experimental Materials and Equipment Enter the name of the manufacturer of the following materials and equipment used in the development of this work: PO42.5 grade ordinary silicate cement, water-reducing agent adopts BASF 2651F, nano titanium dioxide, SMF1900-50, V-METER III ultrasonic pulse velocity 160 tester,
Write a single figure caption for Figure 3 and Figure 4 on page 4 relating to titanium oxide. Label each figure with the letters A and B and write in the figure caption Figure 3: A) Nano-titanium dioxide and B) Aqueous solution of nano-titanium dioxide.
Page 5: State the rate of the uniaxial compression test.
Page 5, line 150: 15 pieces of ordinary concrete and NTC3 samples. Was 15 the total for both samples or the total for one type of sample?
Give the dimensions of the compression test specimens. What standard was used for the compression tests? For this work three specimens were tested, generally the mechanical testing standards such as ASTM recommend at least 5 results of each type of specimen, why were only 3 of each tested?
Page 6, line 182 - 187: Is the load cell accurate to 3 decimal places? Standardize the number of decimals throughout the text.
Page 6 Figure caption number 5: Label each figure with the letters A, B and C and write in the figure caption: Figure 3: A) SMF1900-50 Chamber Resistance Furnace, B) Rigid Servo Triaxial Compression Tester, and C) 2V-METER III Ultrasonic Pulse Velocity Tester.
In Figures 6 and 7, it is not possible to read the axis name of the graphs. To improve their presentation in the paper, the graphs should be placed side by side.
In Tables 4 and 5 on pages 8 and 11 respectively, enter the standard deviation of the calculated means.
Standardize units throughout the text. For density, use g/cm3.
Format the numbers in the equations.
Format the text.
The explanation under Figures 9-13 can be included in the captions.
Figures 14-18 can have only one caption. Label each figure with the letters A, B, etc. and write the caption explaining what each figure represents. The explanation for Figures 20-24 can be included in the captions.
The authors have not shown a comparison of the normal concrete constitutive equation curve and the test curve at different temperatures.
Page 21, line 382: What does "the peak strength does not change much, only slightly improved" mean?
The conclusion states: "This article primarily analyses and compares the mechanical properties and durability of ordinary concrete". In the discussion of the results, the issue of durability needs to be better discussed.
It mentions "the stages of elasticity, elastoplasticity, plasticity", but this topic is hardly discussed in the results discussion.
The whole text needs to be organized and clearly discussed.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
I appreciate the efforts made by the authors to investigate the mechanical properties of ordinary concrete and nano-titanium dioxide modified concrete at high temperatures. However, I have some concerns about the validity of the results presented in this paper.
Firstly, the authors provide limited information about the experimental setup and testing procedures used in this study. Without a clear description of the methods used, it is difficult to evaluate the reliability of the results presented. Furthermore, the sample size used in this study is relatively small, which may limit the generalizability of the findings.
Secondly, the stress-strain curves presented in the paper do not provide clear evidence to support the authors' claims about the different stages of concrete behavior at high temperatures. The curves appear to be quite similar for both the ordinary and modified concrete, and it is unclear how the four stages described by the authors were identified.
Lastly, the authors do not provide a clear explanation of how their findings contribute to the existing literature on this topic. While the paper's abstract suggests that the results provide a reference for future research, there is limited discussion of the practical implications of the findings or how they contribute to our understanding of high-performance concrete structures.
Overall, I believe that the authors need to provide more detailed information about their experimental methods and testing procedures, and to provide a clearer explanation of how their findings contribute to the field. Without these additional details, it is difficult to evaluate the validity and significance of the results presented in this paper.
1. Could the authors provide more information about the concrete mixing and curing process used in this study? For example, what was the water-to-cement ratio used in the mix, and how long were the specimens cured before testing? Additionally, could the authors describe how the nano-titanium dioxide was incorporated into the mix, and what percentage of the mix was made up of the nano-particles?
2. How do the mechanical properties of the modified concrete compare to those of ordinary concrete at both room temperature and high temperatures?
3. Were there any unexpected results or challenges encountered during the experimental process?
4. Have you considered conducting additional tests or experiments to further validate your findings? If so, what would be your next steps in this research?
5. it is difficult to assess the reliability and validity of the results presented in this paper. I would recommend that the authors revise the manuscript to include more detailed information about the size of the tested specimen, including the dimensions and any other relevant details such as aspect ratio or surface texture.
6. Therefore, I would like to ask the authors to provide more information about the experimental setup and testing procedures, and to conduct statistical analysis to support the reported results. This would improve the reproducibility of the results and increase the confidence that readers can have in the reported findings.
7. Could the authors provide more information on why 600°C was chosen as the temperature for the high-temperature treatment? Was this temperature chosen based on previous research in this field, or was it chosen for other reasons? Additionally, it would be helpful if the authors could provide some context regarding the effect of such high temperatures on the properties of concrete, and whether 600°C is considered a typical temperature range for such experiments.
8. Some of the figures seem to be blurry or pixelated, could you please provide high-quality versions of these figures,
9. for example, fig6 and fig7, It would be helpful to include axis labels and units on the figures to provide more context and make the data easier to understand. Could you please add these to the figures ?
10. Your paper includes many figures, but there are limited explanations of what the figures are showing and how they relate to your research questions. Could you please provide more detailed descriptions of the figures in the text of the paper?
11. Could you please provide more detailed explanations of each stage in the text of the paper, to help readers better understand the significance of the observed trends.
12. Finaly, I would suggest that the authors have the manuscript proofread by a professional editor or a colleague with strong English language skills. This could help to identify areas where the text could be improved and ensure that the manuscript meets the highest standards of clarity and readability.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript, in my opinion, has one main weak point: there is confusion, in the exposition about diagrams, models, eqns. etc. , in the sense that is not clear which ones refer to phenomena taking place "at" a certain temperature and phenomena taking place "after" the exposition at certain temperature.
The term "thermal treatment" is itself confusing since remind the positive effect of thermal treatments of metals.
Secondly, some applications listed in the introduction concerne the exposition of concrete to thermal cycles, therefore some acknowledgement to damage accumulation and non conservative phenomena should be added to the manuscript.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
I have reviewed your study on the constitutive relationship between ordinary concrete and nano-titanium dioxide-modified concrete at high temperature and appreciate the valuable insights it provides. However, I would like to highlight the importance of improving the quality of the figures and overall paper structure for better readability and clarity.
Firstly, it would be beneficial to enhance the figures included in the paper. Clear and well-labeled figures aid in understanding the experimental setup, data analysis, and results. Ensuring that the figures are visually appealing and effectively convey the relevant information will significantly enhance the overall presentation of your research.Additionally, I recommend focusing on the organization and structuring of the paper. A logical flow of information and a well-defined structure help readers navigate through the study effortlessly. Consider providing clear section headings, subheadings, and properly linking the different sections to present a coherent narrative.
Finally, I would encourage the authors to consider revising the writing style to make the paper more engaging and easier to read, while still maintaining a scientific tone and rigor.
-What was the specific concentration of nano-titanium dioxide used in the modified concrete, and how was it determined? Were any other additives or materials used in the modified concrete, and if so, how did they affect the results?
-How were the damage variables in the unified constitutive model related to the microstructure and composition of the concrete specimens? Were any other factors considered in developing the model, such as curing time or environmental conditions?
-How did the stress-strain relationship of the nano-titanium dioxide-modified concrete compare to that of ordinary concrete under high-temperature conditions? Were there any significant differences in ductility or other mechanical properties between the two types of concrete
-I would like to suggest considering the inclusion of relevant works that could further enrich the discussion and support your findings like "An investigation of hygrothermal aging effects on high strain rate behaviour of adhesively bonded composite joints. Composites Part B: Engineering, 172, 111-120. and " A critical assessment on the effect of nano-titanium dioxide on the properties of concrete. Građevinar, 74(07.), 553-560."
-Can you provide more details about the splitting failure observed in both types of concrete after high-temperature treatment?
-To enhance the robustness and credibility of your research, I would like to suggest considering the inclusion of reproducibility tests. Replicating the experiments under similar conditions and validating the obtained results would strengthen the reliability of your findings.
-Additionally, it would be beneficial to provide statistical values for your experimental investigations. Statistical analysis helps in quantifying the variability and uncertainty in the data, enabling readers to assess the significance of the observed differences between ordinary concrete and nano-titanium dioxide-modified concrete at high temperatures.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Authors revised
Author Response
Thank you to the reviewers for reviewing the manuscript.
