Shear Behavior of Non-Stirrup Ultra-High-Performance Concrete Beams: Contribution of Steel Fibers and UHPC

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript "Shear behavior of non-stirrup ultra-high performance concrete beams: Contribution of steel fibers and UHPC" represents a comprehensive analysis of the factors that influence the shear behavior of non-stirrup UHPC beams. This is an interesting article, especially from practical point of view, and is worth being considered for publication after some major revisions. With some more analyses and discussions, this paper would be a great read.

1.     I believe the paper needs a revision on the introduction, especially on different recently proposed models and approaches on the topic. I highly recommend authors to amend the introduction on the issue by adding more recently published papers. Following articles are recommended (just as an example. There are a lot more):

-        https://doi.org/10.1016/j.jobe.2024.109577

 

2.     There are also several good papers in this journal. Please have a look at this journal for possible related articles on the topic.

3.     The part, related to results, is indeed very comprehensive and interesting. Yet, there is hardly a good discussion. A better discussion must be added to the article, taking into account other published papers and comparing your results with results from the literature.  

4.     The specification and standards for the mechanical tests must be given in more details.

5.     The errors and accuracy of data must be explained. How many times have you done experiments? Are they repeatable?

6.     Do we really see a meaningful difference between steel fibre 1.5 and 2% in terms of obtained data? Or it is all about some scattering in data? Please explain…

7.     Please report YS and UTS in one single digit (for instance 415 MPa).

8.     You have included interesting pictures from crack patterns. Please add more discussions on theses patterns. What do the differences in these crack patterns imply?

9.     Adding error bars to Fig. 13 is very helpful.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Comments to the authors

Dear authors,

Authors have done a good work entitled “Shear behavior of non-stirrup ultra-high performance concrete beams: Contribution of steel fibers and UHPC”.

Here are some minor comments for your paper which can be addressed.

1. In the abstract, please describe how many shear span to effective depth ratios have been considered. Explain

2. Introduction lacks clarity in utilizing the different types of steel fibers in concrete in terms of strength properties. Authors are recommended to add some recent literature.  In Introduction section, related previous works needed to include and the shear behavior of FRP RC members should critically discussed. Refer and cite these key papers by Garcia et al. and Chaudhary et al. to improve the manuscript quality: Performance of FRP stirrup: and design provisions:

·         https://doi.org/10.1016/j.engstruct.2024.118247

3. Research significance can enhance the idea of the research. So, it is suggested to add research significance.

4. How did the authors conclude the utilization of huge amounts of cement in terms of carbon footprint?

5. In figure 5, please explain what is 1.5% and 2%?

6. Discuss and refer the previous study using DIC to capture shear deformation.

7. Please improve the quality of figure 6.

8. In the manuscript, figure 2 comes after figure 5. Please check.

9. Renumber the figure numbers as the mentioned numbers are not appropriate in the manuscript.

10. It is recommended to put figure 8 on a single page.

11. Please explain the equations separately and clearly with equation numbers and explain the notations below the equations.

12. It is suggested to club figure 9 parts into equal distribution.

13. What is the difference between figure 12 and figure 9. Explain

14. It is suggested to remove table 9 from the conclusion part.

15. Please write conclusions in the precise way as too many irrelevant conclusions are presented.

16.     The statistical significance of the results is not adequately addressed. Discuss why certain results may differ and what factors could contribute to these differences.

17      Expand the discussion to include potential applications of the findings in real-world scenarios. Discuss how the use of synthetic fibers and FRP bars could impact the design and construction of concrete structures, especially in terms of sustainability and cost-effectiveness.

18    Conclude by emphasizing the observed contribution of fiber addition in the concrete mix to enhancing shear resistance.

19    There are several grammatical errors and awkward phrasings throughout the paper. Proofread the paper thoroughly to correct grammatical errors and improve overall readability. Consider having a native English speaker review the manuscript.

20    All reference needs to be revised according to MDPI guidelines (all authors, title, publisher, publisher location (city and country), publication year, and page). Ensure that all references are up-to-date and relevant to the study. Consider including more recent studies that have investigated similar topics to provide a comprehensive background and context for the research.

 

 

Comments on the Quality of English Language

There are several grammatical errors and awkward phrasings throughout the paper. Proofread the paper thoroughly to correct grammatical errors and improve overall readability. Consider having a native English speaker review the manuscript.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

In this paper, the authors report the findings of an experimental research into the factors that influence the shear behavior of non-stirrup UHPC beams. The authors consider that stirrups and bend-up reinforcement in ultra-high-performance concrete (UHPC) beams could potentially be excluded due to the superior mechanical properties of this type of concrete. This may reduce the amount of reinforcement used in beams, but also benefit the execution process. To carry out the study, the authors used 14 beams with different dimensions and with/without stirrups reinforcement. After subjecting the probes to three-point bending tests to evaluate the shear behavior of beams, the authors provide a comprehensive evaluation of the shear behavior, failure modes, and shear strength of non-stirrup UHPC beams, considering the effect of different factors. The results are supported by a comprehensive analysis of digital image correlation (DIC) and non-contact strain testing system. Furthermore, the results were compared with those that would be obtained numerically with the French standard formulae, the PCI formulae, and Xu's formulae. Consequently, the authors present a very adequate paper that exceeds the minimum standards for publication in this journal. In addition, the paper is of high scientific interest and both the methodology and the presentation of the results are appropriate and easy to read and understand. Consequently, I consider that the work should be accepted, in the absence of a minor revision, which is detailed be

I think it would be appropriate to modify the abstract to include more information about the most relevant conclusions of the paper.

Throughout the text there are some errors that need to be corrected in terms of formatting. In line 32-33 there is a blank space which should be corrected. On the other hand, the order of the images is not correct (figure 1, figure 5, figure 6, figure 7, figure 2 etc...). The authors should correct this. 

In the introduction section, the authors mention that it is common to use 2% fibre content. The authors, in addition to mechanical aspects, should support this reflection by including some bibliographical reference indicating that for higher percentages the price increases considerably, or that it is not beneficial to use higher percentages, neither in mechanical properties nor in durability. This can be supported with new bibliographical references.

In table 6, I think it would be appropriate to include the failure pattern codes in the legend. with this in mind, if the authors consider it appropriate, it would be appropriate to include a list of abbreviations.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Very well revised. The paper is acceptable. 

Author Response

Thank you very much for your valuable comments. We appreciate your attention and encouragement.