Deformation Mechanisms of Magnesium Silicate Hydrate Cement with a Shrinkage-Reducing Admixture under Different Curing Conditions

Round 1

Reviewer 1 Report

This manuscript investigates the effect of shrinkage-reducing admixture (SRA) on the shrinkage properties of Magnesium silicate hydrate (M-S-H) cement. This research is meaningful for the development and application of M-S-H cement. The paper can be published after minor revision. Some detailed comments are as follows.

1、Some grammatical and English errors can be seen. Please carefully correct the writing throughout paper.

2、It is suggested to supplement the research status on controlling the shrinkage of cement mortar and use of SRA. And, the authors fail to clearly present the innovations over previous work.

3、The national standard based on the test in the article should not be the latest version.

4、The samples for the characterization tests are not specified, M-S-H cement paste or mortar.

5、In Section 3.2, the effect of SRA on the heat release of M-S-H cement hydration at each stage is not analyzed in detail.

6、There are too many figures in this manuscript. It is suggested to delete  or reorganize some unimportant ones, e.g. Fig. 1, 15, and 16(c).

7、It's better to provide recommendations for further investigation.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

1) The abstract could be extended, including the novelty, main results and conclusions and the possible usability of the research. 

2) The literature review does not include a review of recent literature on the subject (last 0-3 years).

3) The introduction does not describe the necessity and novelty of the current study in light of the existing scientific literature.

4) Does the data reported in Table 1 and Figure 1 measured by the authors or cited from the manufacturer's data? What is the variability of the constituents? How many samples were tested?

5) In table 1, the composition of MgO does not add up to 100%. 

6) The sample numbers and the environmental conditions during sample preparation and curing are missing from the manuscript. Authors only give environmental conditions until the first 24 h of the curing, although testing the samples up to the age of 28 days. I advise including the sample preparation process for all kinds of tests in general in the specimen preparation subchapter, not separately in the test describing subchapters (however, the test-specific environmental conditions should be discussed under the test subchapters).  

7) Standards are literature which also needs to be cited and included in the list of references. 

8) Please include the manufacturer and country of origin for all the used instruments and equipment and their accuracy. 

9) Figure 9 looks nice, but it is hard to read the data, and the error bars are also not visible well. I may advise using different graphs.

10) Methodology is described in the results chapter, e.g. calculation of surface tension. This part belongs to methodology.

11) In the case of Fig. 11. a, I may advise labelling the y-axis as "Rate of heat evolution" instead of heat flow. Fig.11. b should be labelled as "accumulated heat release", not simply heat.

12) In the case of Fig. 12 and 13, "weight loss" should be labelled "residual mass". 

13) I also miss the conclusion chapter's usability and further research perspectives. The conclusions do not include limitations of the study and are general without mentioning exact results.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The manuscript is improved, but there are a few, which need to be addressed:

1) Authors deleted Figure 1, as far as it seems, which is okay. However, they deleted Figure 2, which in my opinion, should remain within the paper and maybe even be extended with a schematic drawing of the position of the sensors within the samples. 

2) Since Table 1 shows data obtained from a third party (manufacturer), I suggest citing the data source in the paper. 

3) Methodology of calculating the surface tension is still shown in the results chapter and not in the methodology. Although the data used is measured, the method description of obtaining the surface tension using measured data and the equation belongs to the methodology chapter. The equation that the authors use is not a result of their work (lines 283-28). Therefore, it belongs to methodology.  

Author Response

Please see the attachment.

Author Response File: Author Response.pdf