Effect of Water on the Dynamic Tensile Mechanical Properties of Calcium Silicate Hydrate: Based on Molecular Dynamics Simulation

Round 1

Reviewer 1 Report

33-36 Please explain sentence: dynamic compressive strength of cement mortar increased with         an increase in water content and dynamic compressive strength of the saturated                 concrete is lower than totally dry

93       4a( a italics)

107     Please explain directions x, y, z 

110     What are a=2.23nm, b=2.22nm, c=2.28nm dimensions? Please mark in figure 1

114     Lammps or Limpton?

143    totally not toally

145    totally not toally

149    yield platform ? maybe curve?

151-153     Sentence: "in addition....." is correct for strain rate in figure 4 a, b, c. For d we can't                 state clearly

155    yield platform ? maybe curve?

162    about 29%

163    about 36% this same in 166

198    Please explain directions z

199    What is the dimension of the model in Figure 6?

205    Formula (1) please explain △z, S_r, and R²

217    Please explain colours like in figure 1. (keep compatibility)

243    Please explain σ_sr

245 - 246    What it comes from?

251 - 254    Incomprehensible sentence, are You sure that in line 252 should be "by"?

258    Formula (3) please explain r

263    σ_s is tensile stress, ε_s what type of the strain

266    Adsorption or absorption?

271    Line in figure 8 (c) should have this same typ what in a and b for respectively degrees of               saturation

281    Please check if the values in the table are consistent with the drawing, in this scale line i           think that for saturated ) should be more than 5.5

282    "The As shown" ? i don't know what it means. f_p,sr is described peak tensile strength ( this             same is in line 263, but with different symbols), i think that should be i. e.  peak tensile                 strength for adequate saturation.

283,289    Forumla (5) - I think it is a big mistake and it should be 5.42 not 5.24. Please check if                 the calculations are correct !!!

287    Forumla (6) - I think it is a big mistake and it should be 5.42 not 5.24. Please check if the             calculations are correct !!!

293    One more time described peak tensile strength but symbols are different than in line 263.

314 - 316 All symbols should have a description: "with different degree of saturation" or " i. e. for                     "adequate saturation"

320    I think that should be f^d_P,Sr not f^d_P,S0

323    like in line 320

343    Ttable 5 not 4

343    Table 5 the value 5.24 is not compatible with Figure 4(a) !!!

346    Please explain ε (with a dot symbol)

349    I think that Formula (17) is wrong, lost minus before before α_d coefficient !!! Please                 check if the calculations are correct !!!

351    This same mistake like in 349. Please check if the calculations are correct !!!

353    Formula (19)  completely incompatible with formula (11). Please check if the                         calculations are correct !!!

356    Values are a large rounding ( up to about 28% ).

358    Formula (20) is wrong, please check previous comments and in addition. values                 should be 4.79 or 4.97? Explain ε ?

365 - 368    If we convert the increase in volume (in model 10,4%) to the actual dimensions                 of concrete samples i. e. 15 x 15 x 15cm, would't they have been destroyed                         earlier?

455    Write all authors

Author Response

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscrpt proposes a different strategy in investigating the mesoscopic mechanical properties of cementitious materials making use of atomistic-level MD simulations. The idea is not new, but it is potentially very interesting. Despite the structure of the paper is quite simple (the authors investigated the variation of the elastic response as a function of two relevant variables: strain rate (from 0.0008 to 0.8 ps^-1 ) and degree of saturation of the interstices (from 0%  to 100 % water molecules), the manuscript is of some interest and, in principle, it could be published in Materials. Prior to be published, however, the text requires a thorough revision in style and content.

A)       Figures are very rough. The authors should add arrows and labels within the images to help the reader to grasp the main message.

B)       The text is too long and boring (are all these fits useful ?) .

C)       The English is poor.

D)       Conclusions are obvious: water concentration decreases the Young modulus and tensile strength of cementitious materials. Can this effect be minimized ?.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The paper submited by Zhou and Liang is well written and is of great scientific interest. I have only few comments and recommend it for minor revision.

Comments:

In the abstract the abbreviation C-S-H appears for the first time, so in the beginning authors should explain this.

The aim of this study shoild be better defined or presents in the clearer way.

in many places there is no space between words. Please check it carefully.

Table 1- there is no statistic for this result. Did you consider providing standard deviation for this calculation?

Figure 5- the plot presents point that are connected with the line. Did you use any fitting for this?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Now it looks better.

Reviewer 2 Report

I asked for a full revision of the manuscript and of the figures. Only minor stylish changes, together with a more precise definition of some equations, have been performed. The doi number was added to the references.

On the basis of these alterations, I'm afraid that I cannot change my judgement.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 3 Report

Authors took into consideration all comments of reviewers. Now the quality of the paper is definitely improved, therefore I recommend it for recommend it for publication in the present form.

Round 3

Reviewer 2 Report

The revised version of the manuscript introduces significant improvements to the quality of the research. In my opinion, the paper can be accepted for publication.