Influence of Stone Powder Content from Manufactured Sand Concrete on Shrinkage, Cracking, Compressive Strength, and Penetration
Round 1
Reviewer 1 Report
please see the attachment
Comments for author File: 
Comments.docx
it is fine
Author Response
Reviewer #1:
This paper deals with an interesting and not-well-investigated topic on the effect of stone powder content in manufactured sand on various properties of concrete (shrinkage, durability, mechanical properties and microstructure). The observed and measured variables include workability, shrinkage strains, cracking resistance, compression strength, electric flux (to estimate permeability), and nuclear magnetic resonance (to estimate porosity) in this research. The manuscript is well written and the observations are well justified. The reviewer believes that the manuscript should be accepted for publication after the following minor revisions:
Response: Thanks for the reviewer's positive comment and recommendation concerning our manuscript. It will encourage us to improve the quality of the revised manuscript.
Point 1: There are problems in the author's ranking and affiliation, please check carefully.
Response 1: We are very sorry for the mistakes caused by our carelessness. We have made modifications in the manuscript, thanks for the reviewer's scrupulous comment.
Point 2: There are errors in the abbreviations of Ca2 + and C3S on the introduction, so it is necessary to check the other parts of the manuscript.
Response 2: Thanks for the reviewer's scrupulous comment. We have made modifications in the manuscript, and carefully checked and modified the manuscript.
Point 3: The both manufactured sand and coarse aggregates in this study are limestone, the manufactured sand and coarse aggregates come from the same manufacturer? Please explain in the manuscript, because the lithology of the parent rock and the crushing process may be a factor affecting the optimal content of stone powder in the manufactured sand.
Response 3: Thanks for the reviewer's scrupulous comment. The crushed stone and manufactured sand selected in this test are provided by the same manufacturer, we have made modifications in the manuscript (see in 2.1 section of “The coarse aggregates consisted of 5–20 mm limestone crushed stone, the MS, SP and coarse aggregates are provided by the same manufacturer.”).
Point 4: The label of the curve C0.32-20 in Figure 4 (b) is suggested to be marked in red. Furthermore, the number colors (i.e. C0.45-0, 0.32-0, … ) in the legend corresponding to their curve colors may achieve better results.
Response 4: Thanks for the reviewer's constructive comment. We have made modifications in the manuscript.
Point 5: Some new, crack and shrinkage-related studies could strengthen the background and introduction part, such as Influences of MgO and PVA fiber on the abrasion and cracking resistance, pore structure and fractal features of hydraulic concrete; Influence of MgO on the hydration and shrinkage behavior of low heat Portland cement-based materials via pore structural and fractal analysis; Comparison of fly ash, PVA fiber, MgO and shrinkage-reducing admixture on the frost resistance of face slab concrete via pore structural and fractal analysis
Response 5: Thanks for the reviewer's constructive comment. We have made modifications in the manuscript, and the newly added references are as follows:
- Wang, L.; Lu, X.; Liu, L.S.; Xiao, J.; Zhang, G.; Guo, F.X.; Li, L. Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis. Fractal and Fractional. 2022, 6(1), 40.
- Wang, L.; Zeng, X.M.; Li, Y.; Yang, H.M. Tang, S.W. Influences of MgO and PVA Fiber on the Abrasion and Cracking Re-sistance, Pore Structure and Fractal Features of Hydraulic Concrete. Fractal and Fractional. 2022, 6(11), 674.
- Wang, L.; Guo, F.X.; Yang, H.M.; Wang, Y.; Tang, S.W. Comparison of fly ash, PVA fiber, MgO and shrinkage-reducing ad-mixture on the frost resistance of face slab concrete via pore structural and fractal analysis. Fractals-complex Geometry Pat-terns and Scaling in Nature and Society. 2021, 29(2), 2140002.
Point 6: The design of the coordinate number size of Figure 7 is unreasonable. It is suggested that the sample C0.45 number can be appropriately reduced. In addition, why is C0.45 concrete only compared in section 3.6, and the C0.32 concrete not included in the comparison list ?
Response 6: Thanks for the reviewer's scrupulous and constructive comment. First, we modify the coordinates of Figure 7. In addition, the reasons why the NMR test results of C0.32 concrete are not listed are as follows: to be honest, we have tested and analyzed the NMR of C0.32 concrete. However, the research show that the change trend of NMR test results of C0.32 concrete is consistent with that of C0.45 concrete. The NMR test results and analysis of C0.45 concrete can fully clarify the influence mechanism of stone powder content on the structure of manufactured sand concrete, adding more data not only does not improve the value of the manuscript but also takes up a lot of space. Therefore, to improve the simplicity and value of the manuscript, we did not include the NMR test results of C0.32 concrete in the analysis.
Point 7: The paper mentioned that 'The optimum SP content of MS concrete may depend on many parameters such as the W/C, amount of cementitious materials, SP characteristics, gradation, aggregate shape, etc.', there is no doubt that the conclusion may be very promising and valuable. Can the author provide more detailed reference for the optimum SP content of MS concrete research and application ?
Response 7: Thanks for the reviewer's positive comment and recommendation concerning our manuscript; it will encourage us to improve the quality of the revised manuscript. Here we hope to do the following explanation: to verify conclusion, we have consulted a large number of research reports and found that the difference of stone powder optimal content in these reports is very large. We analyzed and summarized these literatures in detail, and found that the W/C, amount of cementitious materials, SP characteristics, gradation, aggregate shape of concrete mix, and other parameters determine the role of stone powder in concrete realization such as the filling effect, nucleation effect, dilution effect, or chemical effect. It can be determined that the role of stone powder in concrete is the root cause of its influence on the performance of concrete. However, although we are still continuing to study this problem, due to the limitations of experimental conditions, funding and support, and other reasons, we are currently unable to provide a reliable method to quantify the relationship between key parameters of concrete mix and the effect of stone powder. Undoubtedly, we will try to overcome these difficulties and carry out a more detailed study and exploration of the relationship between the stone powder optimum content and the concrete mix key parameters.
Author Response File: Author Response.docx
Reviewer 2 Report
Concrete is the most commonly used construction material, without which modern construction could not function, it is a material with a high potential to adapt to specific operating conditions. The use of this potential is made by material modification. Therefore, the early shrinkage and cracking properties of MS concrete 60 with different SP contents need to be further studied. In view of this, the limestone SP limestone MS was selects in the test, the workability, early age shrinkage, early age crack resistance, strength, electric flux, and pore structure of MS concrete were tested in this paper. The purpose is to provide a reference for the preparation of MS concrete in practical engineering and to provide a way of thinking for the expanded application of MS concrete in areas with poor sand resources, and to reveal the influence mechanism 66 and influence trend of SP content on MS concrete performance.
The article is well written, I have no comments to the tables and figures.
Author Response
Reviewer #2:
Concrete is the most commonly used construction material, without which modern construction could not function, it is a material with a high potential to adapt to specific operating conditions. The use of this potential is made by material modification. Therefore, the early shrinkage and cracking properties of MS concrete with different SP contents need to be further studied. In view of this, the limestone SP limestone MS was selects in the test, the workability, early age shrinkage, early age crack resistance, strength, electric flux, and pore structure of MS concrete were tested in this paper. The purpose is to provide a reference for the preparation of MS concrete in practical engineering and to provide a way of thinking for the expanded application of MS concrete in areas with poor sand resources, and to reveal the influence mechanism and influence trend of SP content on MS concrete performance.
Comment: The article is well written, I have no comments to the tables and figures.
Response: Thanks for the reviewer's positive comment and recommendation concerning our manuscript. It will encourage us to improve the quality of the revised manuscript.
Author Response File: Author Response.docx
Reviewer 3 Report
This study deals with experimental study of the influence mechanism and influence trend of stone powder content on manufactured sand concrete performance in order to expand application of manufactured sand concrete in areas with poor sand resources to provide a reference for the preparation of manufactured sand concrete in practical engineering. Especially it is considered that the originality of this paper is the estimation of performance of manufactured sand concrete using stone powder with help of the workability, early age shrinkage, early age crack resistance, strength, electric flux, and pore structure by Nuclear Magnetic Resonance (NMR). It is considered that these results in this paper is very useful information for this area of this research field in the future.
However reviewer cannot comprehend the mechanism of fresh concrete and hardened concrete for the influence of stone power content. Reviewer thinks that influence of the dosage of superplasticizer is larger than that of content of stone powder. Furthermore, it is considered that the influence of the entrained-air content of concrete is large. Authors do not describe the dosage of superplasticizer and the entrained-air content at all. In addition, it is considered that the magnitude of early-age shrinkage is very big. Reviewer thinks the early-age shrinkage within 3~72 h is very small and same with different concrete. Then it is considered that the reliability and completeness of this paper is very low.
Therefore, this paper is required to be improved enough to be published in the Journal of Buildings.
Author Response
Reviewer #3:
This study deals with experimental study of the influence mechanism and influence trend of stone powder content on manufactured sand concrete performance in order to expand application of manufactured sand concrete in areas with poor sand resources to provide a reference for the preparation of manufactured sand concrete in practical engineering. Especially it is considered that the originality of this paper is the estimation of performance of manufactured sand concrete using stone powder with help of the workability, early age shrinkage, early age crack resistance, strength, electric flux, and pore structure by Nuclear Magnetic Resonance (NMR). It is considered that these results in this paper is very useful information for this area of this research field in the future.
Point 1: However reviewer cannot comprehend the mechanism of fresh concrete and hardened concrete for the influence of stone power content. Reviewer thinks that influence of the dosage of superplasticizer is larger than that of content of stone powder. Furthermore, it is considered that the influence of the entrained-air content of concrete is large. Authors do not describe the dosage of superplasticizer and the entrained-air content at all.
Response 1: Thanks for the reviewer's constructive comment. First of all, we are very sorry that the reviewers may have misunderstood due to our unclear expression. It should be noted that this manuscript mainly studies the influence of stone powder in the manufactured sand on the performance of concrete to give the best content of the stone powder in the manufactured sand. The change of the dosage of superplasticizer is only to make the workability of the manufactured sand concrete with different stone powder content similar, because the difference between the workability of concrete with different stone powder content will be very significant when the dosage of superplasticizer is the same. Although the change of superplasticizer amount may bring some uncertain factors to the test results of this study, the method of controlling the workability of concrete by changing the superplasticizer amount is widely accepted in the study of stone powder replacing manufactured sand or cement at present. The test results of controlling the similar workability of concrete are also considered to be more effective and reasonable than fixed the amount of superplasticizer. Finally, thanks to the reviewer's questioning of this issue, we added the performance parameters of the superplasticizer in the manuscript 2.1 Section, and also listed the amount of superplasticizer in each test group of concrete in Table 4.
Point 2: In addition, it is considered that the magnitude of early-age shrinkage is very big. Reviewer thinks the early-age shrinkage within 3~72 h is very small and same with different concrete. Then it is considered that the reliability and completeness of this paper is very low.
Therefore, this paper is required to be improved enough to be published in the Journal of Buildings.
Response 2: Thanks for the reviewer's scrupulous comment. We are very sorry that the reviewers may have misunderstood due to our unclear expression, we would like to make the following explanation for the reviewer's questions: as the reviewer said, the shrinkage strain of all concrete samples in this test is very large because the shrinkage and cracking test is performed under curing conditions of 20 ± 2 °C and 60 ± 5% RH. Of course, in the actual project, we will keep the insulation concrete in a good temperature and humidity environment through various curing methods, and their shrinkage strain will be much smaller than the test value of this study. It should be noted that the purpose of selecting this test environment is that it is currently considered that this environment (20 ± 2 °C temperature and 60 ± 5% RH) can maximize the shrinkage strain of concrete; the shrinkage strain of each group of concrete can be greater in this environment, and the influence of the factors we tested on the shrinkage strain of concrete can be compared more clearly. If tested under curing at 20 ± 2 °C and 98 ± 2% RH, the shrinkage strain of each group of concrete may not be significantly different (all concrete samples less than 500 or lower), which will confuse the test results. Although there is no clear standard for the test method of shrinkage deformation of early age concrete at present, the method has been widely accepted and applied in the research field of early age shrinkage deformation of concrete.
In addition, it should be added that the shrinkage and cracking problem of manufactured sand concrete is one of the most concerned problems at present. It is generally believed that the content of stone powder in manufactured sand is a key factor affecting the shrinkage and cracking properties of concrete. Similar to cementitious materials (fly ash, slag), stone powder has the nucleation, dilution, and chemical effect in the concrete mixture, and the content of stone powder has a great influence on the shrinkage performance of concrete. Therefore, the test results of this manuscript are reliable and consistent with the existing research reports as follow.
1) https://doi.org/10.3151/jact.21.307
2) https://doi.org/10.13229/j.cnki.jdxbgxb.20221623
3) https://doi.org/10.13801/j.cnki.fhclxb.20210430.001
4) https://doi.org/10.13229/j.cnki.jdxbgxb20200963
Finally, we are very sorry that the reviewers may have misunderstood due to our unclear expression, and we have supplemented the test environment in Section 3.2 and 3.3 of the manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
Reviewer read author’s response. Reviewer understood the reason and revised part for the influence of the dosage of superplasticizer. For the magnitude of early-age shrinkage, reviewer understood the experimental data. Reviewer does not know it at all and has new knowledge.
Therefore it is considered that this paper revised is to be published in the Journal of Building.
