Experimental Study on the Dowel-Bearing Strength of Bambusa blumeana Bamboo Used for Sustainable Housing Construction
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors performed thorough study, but force-displacement diagrams are overcrowded, which makes results and discussion hard to follow. Data interpretation in the Manuscript must be improved.
Author Response
Thank you very much for reading through our submitted paper. We shall improve the data presentation of our manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsJustification of Methodological Choices need to provide: While the methods are clearly stated, further justification for specific choices (e.g., the selection of sample sizes, dowel diameters, and node placements) in relation to the research questions could strengthen the study's methodological rationale.
Potential Limitations and assumptions of this study need to mention: While the results section is clear, incorporating a discussion on any limitations of the experimental setup or assumptions made during the analysis could offer a more comprehensive view of the findings' applicability.
Interdisciplinary References: Given the interdisciplinary nature of sustainable construction materials research, incorporating references from related fields such as environmental science, material science, and even social sciences could provide additional depth. While the current referencing is adequate, broadening the scope could enrich the article's context.
IF APPLICABLE
Comparative Analysis with other sustainable materials: Including a comparison with other sustainable construction materials, could offer a clearer picture of where Bambusa blumeana stands in terms of strength, durability, cost-effectiveness, and environmental impact.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThis article review relates to “Experimental Study on the Dowel-Bearing Strength of Bambusa Blumeana”. The topic covers a stimulating field within the construction materials discipline. Bamboo was not only a popular material in the past, it’ll undoubtedly constitute the construction of the future based on its inherent/possible economic and environmental capacities. Hence, these types of subjects are extraordinarily impactful for local applications and thus society, especially in developing countries such as the Philippines, where the local application has significant social benefits too (e.g., boosting the industry and further developments, jobs, etc.). All the latter points add to the fascination of the research. Therefore, some points and recommendations to elaborate on the paper to make it up to the level of a valuable journal article for the Sustainability Journal will follow (i.e., as examples to be corrected accordingly throughout the article).
- Since the current research aims to be published in the Sustainability Journal and considering the rich sustainability characteristics of bamboo, discussing and giving a background on the bamboo’s properties regarding the environmental paybacks would make more sense (e.g., making the article more relevant to the subjects; adding to the range of readers, etc.,).
On page one, in the introduction section, lines 33 and 34, do the writers mean “energy-related carbon emission”?
- In scientific writing, speculations must be avoided (e.g., on the first page, the first paragraph of the section, lines 34 and 34, concrete does not comprise the world’s most negative impacts).
With such a limited amount of research and several subjects still to be approved, the formula provided in the conclusions section (i.e., on page 19, paragraph 7, between lines 561 and 562) seems preliminary and a first draft, so it should not have been stated as a “successfully formulated” conclusion yet.
- Similarly, considering several directions that the research tends to prove, the references and literature study are rather limited in supporting all the arguments and, after that, the conclusions.
- Etc.,
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors
Thank you for the opportunity to review the study on the dowel-bearing strength of Bambusa blumeana. This manuscript details experiments to measure the bamboo's resistance to splitting when a dowel is inserted, a crucial factor for sustainable construction using Bambusa blumeana. The research highlights a clear connection between dowel diameter and strength, demonstrating that node placement significantly impacts this property. According to the study, other physical characteristics of the bamboo play a less prominent role. Notably, the study developed a predictive equation to assist engineers in designing bamboo structures with stronger dowel connections, ultimately reducing the risk of failure.
After reading the manuscript, I offer a few comments for your consideration, ranging from minor grammatical issues to more substantive revisions, most of which are for consideration. To facilitate manuscript adjusting, I have organized these comments in the order they appear in the manuscript and marked one "major" comment:
1. The manuscript title is effectively concise and conveys the key message. However, I suggest adding the word "sustainability" or something similar to it to enhance its impact and engagement and show the link between the study and the journal topic.
2. The Introduction. The author wrote, "Bamboo is frequently used in roofing material, partition walls, flooring, scaffolding, and reinforcement. Compared to steel, it has a higher tensile strength and elasticity, making it an ideal material for earthquake-prone areas." It is not true; steel offers greater tensile strength than bamboo. Bamboo's flexibility can be beneficial in some earthquake scenarios, but it's not the sole factor for earthquake resistance. Proper engineering design and material selection are crucial. Bambo has limitations in joinery compared to steel.
3. The Introduction. The author wrote, "The International Organization for Standardization (ISO) 22157 is the first international standard on bamboo". Is this the correct way to refer to technical standards?
4. Line 118. There is no such standard as "ISO 22157:2020"; there are "ISO 22157:2019" and "PNS ISO 22157:2020".
5. Line 122, the authors wrote, "The main purpose of this experimental research is to determine the dowel-bearing strength of Bambusa blumeana through tests following the Half-hole Testing Setup from the ASTM D5764 Standard". It is invalid; the ASTM inspires the authors, but they do not "follow" it because they used different in-shape test samples.
1. The Material & Method section. Table 2.1 (should have number 1) shows that 12 combinations were used: the product of three-rod diameters and four locations of nodes in the bamboo sample, but 3/8'' and 5/8'' were incorrectly repeated. Please provide the rod diameters in SI units additionally).
2. Major comment. The Material & Method section. The samples have a cylindrical shape. Unfortunately, their dimensions were given incomprehensibly (the authors wrote, "The cut sample length was determined by the average diameter. For round bars, three diameters (⅜", ½", and ⅝") were used, with a constant length measured as the diameter plus two inches (or four (4) rod diameters), approximately 150mm."). Does this mean that the diameter of the sample was 150 mm. Its height was 150 mm? And what were the diameters of the "half-holes"? Such as the diameters of the "round bars" used, 1 mm more? (is this information given in line 172?). How can I understand the information "For round bars, three diameters […] were used"? Why do the authors not provide the SI unit in brackets? Please provide a clear dimensions of the samples in the Material and Method secion, and please do not spread this information or repeat it in several places.
3. Line 169. The authors wrote, "The steel plate dimensions were consistent—approximately 100 mm in height and 150-mm in length—for all three plate-mounted round bar diameters." What is the thickness of this plate? Why is there a hyphen between 150 and mm?
4. Line 172. "hole diameter was determined as the round bar diameter plus one (1) mm". What mean "one (1) mm"? (the ASTM D 5764 says: "for bolts, the hole shall be 1⁄16 in. (1.6 mm) larger than the bolt diameter"; and "when pilot holes are used with nails, they shall be less than 75% of the nail diameter"). Why you used 1 mm, and why this form of writing?
5. Figure 2.1. The authors use a synonym for "Bar Diameter" (table 2.1) and call this dimension "round bar diameter", and even introduce a new term "dowel" in the figure caption. It's best to stick to the established terminology for very specific technical terms to avoid ambiguity.
6. Figure 2.2. The dimensions of the samples are missing from the drawings.
7. Line 203. "rate of movement at 2 mm per minute". Why is "mm" abbreviated while "minute" is not?
8. Line 211. "Is "the standard range of 9%-11%" correctly written?
9. Figures 3.1.1-3.1.12. The authors presented the raw data in these figures. These data should be placed in the Appendix because figures 3.2.1 and 3.2.2 present the results sufficiently.
10. Section 3.8. The author proposed the equations. Please provide the validity limits for these equations (what ranges of parameters can be entered into these equations?).
11. The conclusions could be strengthened by emphasizing the broader significance of the research. How do these findings impact the use of bamboo in construction? How do these findings strengthen sustainable building? In general, the content of the article should emphasize the impact of research on the sustainability of construction.
12. I believe the authors could provide more specific recommendations for future research plans.
Overall, I consider the article a valuable contribution to the field, with some limitations pointed out above.
Sincerely
Comments on the Quality of English LanguageDear Authors,
The manuscript is well-written. However, a few minor revisions can further enhance clarity and flow. For example in the introduction: instead "In modern bamboo connection designs, using metal to join culms contributed to its reliability and ductility", better" "Using metal to join culms in modern bamboo connection designs contributed to its reliability and ductility". Double-check for any typos or grammatical errors.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have improved data presentation.
Author Response
Thank you a lot for your valuable comments.
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors
Thank you for responding to my review. I appreciate you taking some of my comments into account. However, I noticed that the manuscript title, a statement about the greater tensile strength of bamboo than steel, and others remain unchanged. I also did not find any information on why this was decided. While I appreciate the revised manuscript, some errors remain. These are relatively straightforward to correct and would further enhance the clarity of the work. I believe the manuscript is unsuitable for publication in this form, but can be revised, as I explain below.
1. The manuscript’s title and research aim focus seem less aligned with the core themes of the Sustainability journal. MDPI publishes other journals, such as Materials or Applied Sciences, that might better fit the presented topics. This is my opinion and recommendation to the editor if the authors do not change anything. In the previous review, I suggested that the authors could add the word “sustainable” or something similar to the title. The authors did not do this. I believe that the minimum is to align research aims with environmental goals. Therefore, I recommend revising the aim of the work to emphasize that the aim is also to support sustainable construction.
2. Lines 42-44. The authors wrote, “Compared to mild steel, some bamboo species have similar tensile strength, making it safe for reinforcement in certain conditions and ideal as a construction material”. I am afraid I have to disagree with two statements. 1) Bamboo has similar tensile strength to mild steel. While Mild steel’s Ultimate Tensile Strength (UTS) is 400-550 MPa, and bamboo is 142-265 MPa. 2) bamboo […] is an ideal construction material. This means that bamboo has all the necessary construction properties, surpassing any other construction material. So, should all construction structures be made of bamboo? Bamboo can be a good construction material, especially in specific applications like low-rise buildings or non-structural elements. However, it may not be ideal for all situations compared to steel or reinforced concrete (consider limited availability; even with treatment, bamboo can be susceptible to moisture and insect damage compared to steel, and bamboo generally has lower fire resistance than steel; also consider problems with joinery compared to steel, reinforced concrete or even CLT). Bamboo can be beneficial in some applications but not in all, so it is not an “ideal” construction material. Please provide sources from the literature on the measured tensile strength of bamboo, which is “similar” to the steel UTS. Please remove or rephrase “ideal” or justify using this word. I pointed out this in the first round of review.
3. Lines 133-150. I recommend moving the entire last paragraph of the Introduction section to the Discussion section. Additionally, I propose a minor rewiring of the text and considering citing literature where findings are in line with the authors’ statements (https://doi.org/10.1016/j.jobe.2020.101324 and https://doi.org/10.1155/2021/4788381) (“As mentioned previously, ISO 22157 currently lacks dowel bearing strength testing specifications. This highlights the need to establish specific properties of bamboo to improve research on joints of chosen species continuously. While ISO 22157 is not explicitly limited to bamboo dowel bearing strength, the mechanical properties established require extensive experimental data, which is where this research gains significance. Developing joints requires much-needed data on bamboo properties, including thickness, height, node distance, moisture content, and dowel-bearing strength. Finding the optimal parameters for maximum dowel bearing strength would determine the ideal joint conditions. Node distance would indicate the best location for high-performance bolt placement, and thickness would guide the selection of members for specific loads. These results would significantly enhance research on bamboo joints, which would steer future studies on various parameters’ positive and negative performance impacts. Additionally, the experimental results would contribute to completing the foundation of ISO 22157, consequently aiding the National Structural Code of the Philippines (NSCP) in establishing specified bamboo species’ physical and mechanical properties. This would ultimately broaden the possibilities achievable with bamboo structures.”).
4. Table 2.1. Thank you for adding millimeters; however, please provide dimensions in millimeters that are accurate to one decimal place.
5. Line 196. Instead of “plus one (1) mm”, it should be “plus 1 mm” or “plus one millimeter (1 mm)” – I pointed out this typo error in the first round of review.
6. Figure 2.2. The sample size remains unspecified; the node placements without the overall dimensions of the samples are insufficient. Please specify the overall dimensions of the samples. I pointed out this in the first round of review.
7. Figure 2.3. Instead of “sample thickness”, it should be “wall thickness”. Please revise.
8. Line 306. Instead of “15471.15N, 31.0%-40.0%”, it should be “15,471.15 N, 31.0-40.0%” (use a thousand separator to improve readability by grouping digits in large numbers – ISO recommends a space as the separator for thousands, but this is not widely adopted; use a space before unit; and straightforward way to show a range of numerical values, “31.0-40.0%” is the better option). Please revise the whole text accordingly.
9. Eq. 2. Please separate the equation from the explanations of the variables.
10. Line 382. Asterix (*) is not a universally accepted multiplication sign. Please correct.
11. Please consider strengthening the Discussion section by citing some literature sources. I propose considering to add in line 394: “Lignocellulosic materials are natural resources that can be replenished in engineering through sustainable practices (https://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-BAT8-0013-0046). This makes them more eco-friendly than traditional construction materials like steel and concrete. Bamboo construction materials especially offer environmental benefits, contributing significantly to sustainable practices in various applications. The construction industry can reduce energy consumption from 3% to 5%, and CO2 emissions from 7% to 20% by using these materials (https://doi.org/10.1080/17452007.2023.2195614). Bamboo can replace steel in construction. Joints made of bamboo with T-stubs can have a higher load-bearing capacity and initial stiffness than steel equivalents (https://doi.org/10.1007/978-981-19-7331-4_103). Gondane et al. (2022) developed a mathematical model to analyze the performance of a four-bar mechanism. Their model incorporates a sic chain mechanism with linkages and joints made from bamboo, utilizing appropriate adhesives at the bamboo connections. The results of their investigation predict the feasibility of replacing the existing material in the four-bar mechanism with bamboo (https://doi.org/10.1007/978-981-19-3716-3_60). However, enhancing bamboo integration in modern structures requires strong metal joints (https://doi.org/10.3992/1943-4618.13.2.1) and appropriate design of bamboo structures. For example, a two-culm beam shows significantly improved flexural bearing capacity (https://doi.org/10.3390/f13111851)”.
12. Line 442. Please write “2” in superscript (R raised to the power of 2).
Please consider my comments. I’m happy to discuss them further if you have any questions—best of luck with your publication and future work.
Sincerely
(–)
30.04.2024
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 4 Report
Comments and Suggestions for AuthorsDear authors, thank you for considering my comments from the previous two rounds of reviews. I do not have any additional substantive comments, but I would like to point out a few minor errors in the presentation of information: 1. Fig. 2.2. If you use millimeters, use them consistently. I suggest providing all dimensions in millimeters (now height is in cm). Please also use abbreviations consistently ("height" is shortened to "H", and the diameter is written as a whole - "Diameter"). The unit must be added with a space after the number ("20 mm").
2. Fig. 2.3. The font used is too small and is inconsistent with the other figures in the manustript. I suggest using the same font.
3. Fig. 2.4. The capitalization of letters was used - it is inconsistent with the other figures. I suggest using writing of the same grade and type as in the other drawings.
4. Fig. 3.8.1 Typo error "Coverted" instead of "Converted". Whether "Converted node distance" has a unit. If so, please provide it.
5. Fig. 3.8.2. Typo error, instead of (mm^2)" should be "(mm2 - it is possible in Excel)".
Despite these minor shortcomings, I mark "accept in present form" and recommend it for publication.Good luck.
Kind regards,
Author Response
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Author Response File: Author Response.pdf
