Synergistic Bond Properties of Different Deformed Steel Fibers Embedded in Mortars Wet-Sieved from Self-Compacting SFRC
Round 1
Reviewer 1 Report
I think the paper can be published in current version.
Author Response
Thanks very much for your ’ evaluation and comments on paper applsci-1415623. Here, we have made extensive modification on the original manuscript, and carefully proof-read the manuscript to minimize typographical, grammatical, and bibliographical errors. The main revised parts are represented as Red.
Reviewer 2 Report
The reviewer appreciates the experimental work done by the authors. The technical contents of the paper are in general interesting. The findings from this study are useful information for field applications in the future. In the reviewer’s opinion, the goal of the work must be better explained within Abstract, Introduction and Conclusions. Moreover, the publication in the “Applied Sciences” is not recommended unless the following suggestions are taken into account within the article:
1. The current state of knowledge relating to the manuscript topic has not been covered and clearly presented, and the authors’ contributions are not emphasized. In this regard, the authors should make their effort to address these issues, by adding additional comments on the state of the art and the proposed aspects.
2. Objectives and information should be presented more clearly. Furthermore, additional comments should be added in regard to the practical value of this work, and how the industry can profit from this article.
3. Introduction: Fiber reinforced mortars can particularly improve the durability of reinforced and prestressed concrete structures. Please, mention this issue and, consequently, cite the following corresponding references:
a- Dynamic modulus for reinforced concrete beams. Journal of Structural Engineering, 1984, 110(6), 1405–1410.
b- Prestress force effect on fundamental frequency and deflection shape of PCI beams. Structural Engineering and Mechanics, 2018, 67(3), pp. 255–265.
4. The sections within the article do not show clearly the compression tests executed on the mortars under investigation. Please, insert photos and corresponding geometric dimensions of compression tests in which samples and devices are visible.
5. The sections within the article do not show clearly the pull-out tests performed on the mortars under investigation. Please, insert photos and corresponding geometric dimensions of pull-out tests in which samples and devices are visible.
6. Please, provide the frequency (or the period) of the recording data by all the equipment and devices used.
7. Please, provide the technical characteristics of all the equipment and devices used.
8. Material strengths are usually provided with a tolerance of 1 MPa. Within the article, the strengths of mortars have been furnished with tolerances of 0.1 MPa and 0.01 MPa. Are such tolerances reliable measurements regarding the experimental work performed ? Please, specify.
9. I suggest to the authors to edit all the text of the article with the help of a native English speaker. Grammar, punctuation, spelling, verb usage, sentence structure, conciseness, readability and writing style could be improved.
Author Response
Thanks very much for your evaluation and comments on paper applsci-1415623. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. Here, we have made extensive modification on the original manuscript, and carefully proof-read the manuscript to minimize typographical, grammatical, and bibliographical errors. The main revised parts are represented as Red.
Comment 1: The current state of knowledge relating to the manuscript topic has not been covered and clearly presented, and the authors’ contributions are not emphasized. In this regard, the authors should make their effort to address these issues, by adding additional comments on the state of the art and the proposed aspects.
Response: Thanks for your kind reminder. The current state of knowledge relating to the manuscript topic has been clearly revised in line 82-84, line 89-91, line 114-116, line 124-125 and line 136-141 in the revised manuscript. The authors’ contributions are emphasized in the line 145-156 in the revised manuscript.
Comment 2: Objectives and information should be presented more clearly. Furthermore, additional comments should be added in regard to the practical value of this work, and how the industry can profit from this article.
Response: Thanks for your kind reminder. Objectives and information are presented more clearly in the line 26-28, line 155-156, line 205-215 and line 222-227 in the revised manuscript. additional comments were added in regard to the practical value of this work, in the line 527-532 in the revised manuscript.
Comment 3: Introduction: Fiber reinforced mortars can particularly improve the durability of reinforced and prestressed concrete structures. Please, mention this issue and, consequently, cite the following corresponding references:
a- Dynamic modulus for reinforced concrete beams. Journal of Structural Engineering, 1984, 110(6), 1405–1410.
b- Prestress force effect on fundamental frequency and deflection shape of PCI beams. Structural Engineering and Mechanics, 2018, 67(3), pp. 255–265.
Response: It has been revised in the line 82-83 in the revised manuscript.
Comment 4: The sections within the article do not show clearly the compression tests executed on the mortars under investigation. Please, insert photos and corresponding geometric dimensions of compression tests in which samples and devices are visible.
Response: The compression tests executed on the mortars are presented in Figure 3 in the revised manuscript. The geometric dimensions of strength samples is presented in line 197 and line 199 in the revised manuscript.
Comment 5: The sections within the article do not show clearly the pull-out tests performed on the mortars under investigation. Please, insert photos and corresponding geometric dimensions of pull-out tests in which samples and devices are visible.
Response: It has been revised. The geometric dimensions of pull-out sample are presented in Figure 4. The Detailed test devices are presented in Figure 5 in the revised manuscript.
Comment 6: Please, provide the frequency (or the period) of the recording data by all the equipment and devices used.
Response: It has been revised in the line 221-227 in the revised manuscript.
Comment 7: Please, provide the technical characteristics of all the equipment and devices used.
Response: It has been revised in the line 223-225 in the revised manuscript.
Comment 8: Material strengths are usually provided with a tolerance of 1 MPa. Within the article, the strengths of mortars have been furnished with tolerances of 0.1 MPa and 0.01 MPa. Are such tolerances reliable measurements regarding the experimental work performed? Please, specify.
Response: The cube compressive strength fcu and splitting tensile strength fst of self-compacting SFRC were tested according to the specification of China code GB/T50081. The tolerances of compressive strength and splitting tensile strength of concrete are 0.1MPa and 0.01MPa, respectively. The compressive strength fcm and flexural strength ffm of wet-sieved mortar were tested according to the specification of China code GB/T17671. The tolerances of strength of mortar are 0.1MPa.
Comment 9: I suggest to the authors to edit all the text of the article with the help of a native English speaker. Grammar, punctuation, spelling, verb usage, sentence structure, conciseness, readability and writing style could be improved.
Response: Thanks for your kind reminder. we have made extensive modification on the original manuscript, and carefully proof-read the manuscript to minimize typographical, grammatical, and bibliographical errors.
Author Response File: 
Author Response.docx
Reviewer 3 Report
The topic is suitable for the journal. However needs to mention the novelty of the work (i.e. new aspects of the work by referring to recent references.
The title should be improved
A sketch of the pull-out test would be useful
Figure 5…..The various terms are not fully explained Wr Wp Wd
Good to include some values regarding trends in the results
English requires improvement in many places (examples are given below)
Abstract: Reliable bond of [[ steel fiber ]]]] in concrete is a key problem relating to the reinforc-
ing effect of [[ steel fiber ]] on concrete. It also has important [[ guiding significance ]]]] for the opti
mal design of the geometrical shape and mechanical properties of steel fiber. In this paper,
pull-out tests were carried out for different deformed steel fibers embedded in [[ mortars wet-sieved ]]] from self-compacting SFRC with manufactured sand. Fourteen types of steel
fibers were used, including six of hooked-end, two of crimped, four of indentation, one
of milling and one of large-end. The bond strength, bond energy and bond toughness of
fiber in accordance with cracking resistance, the normal serviceability and the ultimate
bearing capacity of concrete were evaluated. Results showed that, hooked-end and
crimped steel [[ fibers ]] with suitable [[ fiber ]] strength and circular cross-section matches well
with the self-compacting concrete of w/b=0.31. These steel fibers have excellent strength
reinforcement, energy dissipation effect and toughening capacity in the normal servicea-
bility and ultimate bearing capacity of concrete. The indentation, milled and large-end
steel fibers are more suitable for reinforcing the concrete strength with normal strength
due to the rigid bond mechanism design and their excellent properties before concrete
cracking.
After decades of research, the mechanism of [[ steel fiber ]]]] reinforcing concrete becomes 32
much more clearly understood. The bond performance is the key issue of [[ steel fiber ]]] with 33
cementitious matrix of concrete to ensure the strengthening and toughening effects of
[[[ steel fiber ]]] on matrix [1-5]. This is also essential to the [[ rational ]]] optimization of the mor-
phology and geometric dimension of steel fibers used for reinforcing concrete.
Author Response
Dear reviewer
Thanks very much for your evaluation and comments on paper applsci-1415623. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. Here, we have made extensive modification on the original manuscript, and carefully proof-read the manuscript to minimize typographical, grammatical, and bibliographical errors. The main revised parts are represented as Red. Here below is our description on revision according to your comments.
Comment 1: The title should be improved.
Response: Thanks for your kind reminder. The title has been revised as “Synergistic Bond Properties of Different Deformed Steel Fibers Embedded in Mortars Wet-sieved from Self-compacting SFRC” in the revised manuscript.
Comment 2: A sketch of the pull-out test would be useful.
Response: Thanks for your kind reminder. It has been added in Line 32-76, in the revised manuscript.
Comment 3: Figure 5…..The various terms are not fully explained Wr Wp Wd
Response: Thanks for your kind reminder. the debonding work Wd are the area of the pull-out load-slip curve from 0 to slip sd. the slipping work Wp are the area of the pull-out load-slip curve from 0 to slip sp. the pull-out work Wr are the area of the pull-out load-slip curve from 0 to slip sr. The formulas of Wr, Wp, Wd are presented in line 281-283 in the revised manuscript.
Comment 4: Good to include some values regarding trends in the results
Response: It has been revised in line 503-522 in the results of the revised manuscript.
Comment 5: English requires improvement in many places (examples are given below)Abstract: Reliable bond of [[ steel fiber ]]]] in concrete is a key problem relating to the reinforcing effect of [[ steel fiber ]] on concrete. It also has important [[ guiding ignificance ]]]] for the optimal design of the geometrical shape and mechanical properties of steel fiber. In this paper,pull-out tests were carried out for different deformed steel fibers embedded in [[ mortars wet-sieved ]]] from self-compacting SFRC with manufactured sand. Fourteen types of steel fibers were used, including six of hooked-end, two of crimped, four of indentation, one of milling and one of large-end. The bond strength, bond energy and bond toughness of fiber in accordance with cracking resistance, the normal serviceability and the ultimate bearing capacity of concrete were evaluated. Results showed that, hooked-end and crimped steel [[ fibers ]] with suitable [[ fiber ]] strength and circular cross-section matches well with the self-compacting concrete of w/b=0.31. These steel fibers have excellent strength reinforcement, energy dissipation effect and toughening capacity in the normal serviceability and ultimate bearing capacity of concrete. The indentation, milled and large-end steel fibers are more suitable for reinforcing the concrete strength with normal strength due to the rigid bond mechanism design and their excellent properties before concrete cracking.After decades of research, the mechanism of [[ steel fiber ]]]] reinforcing concrete becomes much more clearly understood. The bond performance is the key issue of [[ steel fiber ]]] withcementitious matrix of concrete to ensure the strengthening and toughening effects of[[[ steel fiber ]]] on matrix [1-5]. This is also essential to the [[ rational ]]] optimization of the morphology and geometric dimension of steel fibers used for reinforcing concrete.
Response: Thanks for your kind reminder. We have made extensive modification on the original manuscript, and carefully proof-read the manuscript to minimize typographical, grammatical, and bibliographical errors.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have adequately addressed my comments.
Author Response
Thanks for your affirmation.
Reviewer 3 Report
The authors seemed to have addressed my comments and tend to accept. Minor comments:
Is “Wet-Sieved” necessary in the title. Also how was wet-sieved conducted. “Did you add water”
Author Response
Comment 1: Is “Wet-Sieved” necessary in the title. Also how was wet-sieved conducted. “Did you add water”
Response: Thanks for your kind reminder. Yes, “Wet-Sieved” is necessary in the title in my opinion. As the authors want to study the bond properties of steel fiber in concrete by using the mortar specimen. And the mortar is produced with fresh self-compacting SFRC without coarse aggregate and steel fiber. The process of “wet-sieved” is used to assure that the true mix proportion of mortar is same with concrete. The wet-sieved process was presented in Figure 2 in the revised manuscript. Firstly, certain amount of fresh self-compacting SFRC was put in a sieve with square-hole of 5 mm diameter. Then, the fresh mortar with steel fibers were sieved out. After the steel fibers were sucked out by using the magnet, the wet-sieved mortar was obtained. And, we did not add water during the wet-sieved process.
