Impact of Particle Sizes, Mineralogy and Pore Fluid Chemistry on the Plasticity of Clayey Soils

Round 1

Reviewer 1 Report

A/ Major comments:

The paper entitled “Impact of particle sizes, mineralogy and pore fluid chemistry on the plasticity of clayey soils” by J. Won et al. reports a comparison of plasticity parameters measured on the three main clay soils (kaolinite, illite, and montmorillonite-rich soils) and their use to predict the liquid limits and the undrained shear strength. In this original article, the authors highlight the advantage of their approach by including the consideration of ionic concentration, in addition to particle sizes and mineralogy, in geotechnical soil classification. The paper is well written and easy to follow. Overall, I think this study is of interest for the readership of Sustainability. I have, however, identified some minor points on which I would like the authors to pay attention.

 

B/ Minor comments:

1/ The first sentences of the introduction (lines 31-32) must be revised for clarity.

2/ Lines 66-67: this definition of montmorillonite is incorrect. Montmorillonite do contain interlayer charge compensating cations in their structural formula. The difference between illite and montmorillonite stands from the intensity of the layer charge (located within the tetrahedral and/or the octahedral layers). On the on hand, the layer charge of illite (~ 0.75 per formula unit) is compensated by irreplaceable K atoms in the interlayer. On the other hand, the layer charge of montmorillonite (0.4 to 0.75 pfu) is also compensated by interlayer cations (such as Ca, Mg, Na, or K) but, the low charge allows these cations to be hydrated by water molecules. Hence, the interlayer distance may vary upon the amount of water molecules within the interlayer space. The author may read Madsen and Müller-Vonmoos 1989 (The swelling behaviour of clays, Applied Clay Science, Volume 4, Issue 2, 1989, Pages 143-156 – doi: https://doi.org/10.1016/0169-1317(89)90005-7) for a complete understanding of the difference between illite and montmorillonite.

3/ I would believe that the techniques mentioned in lines 70-73 were “performed” on “dry clay powder(s)”, rather than “for”.

4/ Figure 5 is barely readable in the 100% (printed size) view size of the article.

Author Response

Thank you very much for your review. We revised the manuscript based on your comments. The attached file show responses to your comments. 

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors, 

Lines 46-47: The sentence is not clear. Atterberg limits refers to fine grained soils and can be used to distinguish between silt and clay. 

Lines 62-64: The fine materials are commercial or natural? What do you mean by fine material? Is it soil? Sediments? Explain.

Lines 64-69: Add reference

Lines 70-74: XRF does not provide mineralogical information but compositional information. Please revise it. Furthermore, i suggest to add the conditions for each technique. 

Table 1 is not clear. 

Line 117: I suppose according the journal instruction you must number the citation

Lines 146-148: I suggest to mention hydrometer test in methods, even it is not clear if you used the sieving or hydrometer test for the particle size distribution

Figure 2: There is no point to show the SEM images. Otherwise give more information why did you use SEM

Table 2: please add in the caption the abbreviations of ML, CH

Lines 161-168: How did you calculate the mineralogical compositions? Please explain. How did you recognize kaolinite from chlorite? Did  you perform the extraction of the clay fraction in order to recognize the clay minerals? Regarding the Figure 3c, you refer to zeolite whereas you do not mention anything about zeolite within the text. 

Table 3: It does not include all the oxides? Why? What about the total weight of oxides? You do not comment anything about the chemical analyses within the text, but you just give the table. 

Table 4: The same as table 3. What is the purpose of this table? Furthermore, you must convert all the elements inoxides. Minerals are commonly reported in weight percentages of the oxides of the elements determined. Also you recognized clay minerals in which molecular water must be included in the stoichiometry. How is it possible the total to be 100? Is it a semi-quantitative analysis? Please explain. Otherwise the table must be revised or be deleted

The title of the article mentions the effect of the particle size.....on the plasticity of the clayey soils. In the whole text you focus on the liquid limits, but finally it is not clear how all these parameters influence the plasticity. The same also goes to the conclusions. 

Kind regards!

Author Response

Thank you very much for your review. We revised the manuscript based on your comments. The attached file show responses to your comments. 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Dear editor and authors, 

The article can be published as it is.

Kind regards!