Study on the Reinforced Properties of Geopolymer Fibers with a Sustainable Development Role
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper investigated the impact of fly ash to metakaolin ratio, the type and content of fibers on the mechanical performance of geopolymer composites. Questions listed below should be addressed to enhance the quality of the paper:
1. The term "performance study" in the paper's title is not entirely appropriate, the paper mainly investigated mechanical performance rather than comprehensive performance analysis.
2. Section 2 lacks the source and parameter of fibers used in the paper.
3. The preparation method of fiber-reinforced polymer is missing.
4. Title of section 2.1.4, the term “Mechanism Sand” is incorrect.
5. In section 2.2.2, authors mentioned that specimens were cast in the mold with a size of 100mm×100mm×100mm, but the size of the specimen for the bending test was not specified. The loading control parameters for mechanical performance are missing in Section 2.3.1.
6. Line 192, “improving its” is not a complete sentence.
7. Further analysis should be conducted on the XRD test results of Figure 8; authors should further confirm the phase composition, the peak of Na2Si4O9 in line (c) is barely visible; "b:35:35" in the title of Figure 8 is a typo.
8. The last paragraph “This work has received….” should not be in the conclusion section.
Comments on the Quality of English LanguageIt is acceptable
Author Response
Please see attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe article "Performance Study on Fiber-Reinforced Geopolymer" delves into the realm of geopolymers based on fly ash and metakaolin, reinforced with various types of fibers. However, the introduction of the article appears cursory, lacking depth. The citation of only 15 references, mostly focusing on general aspects of construction sustainability, neglects substantial exploration of geopolymers and their fiber reinforcement.
The research plan holds promise, yet its presentation requires significant amendments. Firstly, the authors refer to "geopolymer concrete," yet the composition description suggests the absence of coarse aggregates, which disqualifies the composite from being labeled as concrete. Furthermore, the precursor descriptions solely rely on their chemical composition, disregarding particle size distribution and grain morphology. Even the quoted chemical compositions lack precision, with differing accuracies between Table 1 and Table 2.
The presentation of research findings in Figures 1 to 3 is erroneous. Continuous lines connecting individual results imply a trend that was not present. I suggest considering changing the chart type to bar graphs or another format for result presentation. Moreover, the results are solely depicted as mean values, lacking information on sample size for each composition and testing period. Was it only one sample? If so, the research design is inadequate. If multiple samples were used, such information should be provided, along with standard deviations or other statistical measures.
Despite fibers being the main analyzed aspect, they are not adequately characterized in the section describing the materials used. Their geometry and other characteristics are overlooked. Overall, the idea of enhancing flexural strength is intriguing, but the article requires significant revisions before publication. Additionally, since the article is submitted to the journal "Sustainability," I suggest the authors pay attention to the sustainability aspects of the analyzed composites.
The carbon footprint of geopolymers is undoubtedly lower than that of cementitious composites. However, adding fibers to improve flexural and compressive strength may disrupt this balance. I suggest conducting a multi-criteria comparison, encompassing the analyzed parameters and carbon footprint of composites.
Author Response
Please see attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe objective of this work was to investigate the mechanical performance of geopolymer concrete with an optimum ratio of fly ash and methacrylate as binder, and to evaluate the tensile and flexural strength of geopolymer concrete with different fiber reinforcement. In addition, XRM and SEM techniques were used to determine the microstructure and alteration in the geopolymer concrete. However, there are some concerns raised by the reviewers. After the minor revision, the manuscript could be more valuable to the potential readers of the journal. Please note the following comments.
1. There are several words that look inappropriate or like typos.
On page 1, line 9: the word ‘thatthe’ should be ‘that the’.
On page 7, line 202: ‘found that’ is redundant and should be removed.
On page 7, line 221: the word ‘PP’ should be ‘PVA’.
2. On Page 1, Chapter 1,
It would be better if the introduction mentioned the references related to this study.
3. Table 3
For ease of understanding, please present binders, aggregates, water, admixtures, etc. in kilograms per cubic meter in Table 3.
4. On Page 3, Subchapter 2.2.2,
For ease of understanding, please provide a flow chart and photo of the preparation process as shown in the figure.
5. On Page 4, Subchapter 2.3.1,
For ease of understanding, please provide a photo of the machine and test setup as shown in the figure.
6. On Page 4, line 154,
In this study, the variables were set to 100:0, 35:65, 50:50, 65:35, and 100:0 in the ratio of fly ash to metakaolin. However, the effect is only mentioned when the percentage of metakaolin is greater than 80%. References or additional descriptions are needed.
7. On Page 6, line 172,
It would be better to show the material properties of the fibers by using a table.
8. On Page 6-7,
Since carbon fiber has high strength and high modulus material properties compared to PP fiber, and the increase in tensile and flexural strength of geopolymer concrete at 1.5% volume fraction is similar, it would be good to comment on whether fibers with high strength and high modulus material properties have a significant effect on the increase in tensile strength and flexural strength of concrete.
9. On page 9, last paragraph,
Overall, the sentences should be revised to fit the narrative of Figure 8.
10. Figure 8
Figure 8b indicated 35:35 ratio of fly ash and metakaolin. There is no 35:35 ratio of fly ash and metakaolin in the experiment of this paper.
11. Figure 10, 11, 12, 13, 14
Please add a brief description like fiber, crack on the SEM results photo.
Comments on the Quality of English Language
The quality of English is alright for potential readers to read the manuscript.
However, it can be further improved.
Author Response
Please see attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
Thank you for considering my comments and providing your responses. In my assessment, the article is now ready for publication in its current form.
Kind regards.
Author Response
Thank you so much for agreeing with my post.
Reviewer 3 Report
Comments and Suggestions for AuthorsMost comments from the reviewer have been addressed.
Please consider the additional comments below.
1. Comment No. 5 from the previous review, '5. For ease of understanding, please provide a photo of the machine and test setup as shown in the figure.' has not been addressed in the revised manuscript. If the authors believe it is unnecessary, this comment may be disregarded. However, the response states "I have modified the image as requested," which does not appear to be the case as no modification is found in the revised manuscript.
2. Regarding comment No. 8 from the previous review, the response is "Thank you for the review. This occurred because it was found that carbon fibers were more prone to aggregation compared to PP fibers in the tests."
It is recommended to include a relevant description in the revised manuscript to clarify this point.
Thank you for your revisions.
Please consider the minor revisions along with the additional comments provided.
Author Response
Comments1: Comment No. 5 from the previous review, '5. For ease of understanding, please provide a photo of the machine and test setup as shown in the figure.' has not been addressed in the revised manuscript. If the authors believe it is unnecessary, this comment may be disregarded. However, the response states "I have modified the image as requested," which does not appear to be the case as no modification is found in the revised manuscript.
Response: Thank you for pointing this out. I have added the machine picture in Figure 2.
Comments2: Regarding comment No. 8 from the previous review, the response is "Thank you for the review. This occurred because it was found that carbon fibers were more prone to aggregation compared to PP fibers in the tests. "It is recommended to include a relevant description in the revised manuscript to clarify this point.
Response: Thank you for pointing this out. I've added to this in 3.2.3 in the article.
Carbon fiber is a high-strength, low-density fiber material whose surface is usually subject to electrostatic forces, making it more likely to be clumped together in concrete. Unlike this, polypropylene fibers have relatively weaker and better electrostatic forces and do not tend to clump together.
