The Effect of Fines Content on Compressional Behavior When Using Sand–Kaolinite Mixtures as Embankment Materials

Round 1

Reviewer 1 Report

I find the work quite interesting in rigorously studying the optimal mixture to be used using the area materials and clays. The results very well support the objectives of the work and the conclusions.

One concern that I have on this subject is that not all clays are the same, kaolinite was used here, but in the presence of other types of clays that are swellable, it could deliver another behavior. Could it be the case that these clays appear in the sediments? 

Author Response

The authors appreciate the reviewer’s valuable comment. This paper aims to investigate the effect of fines content on overall behavior of sand-kaolinite mixtures which can represent the embankment materials in South Korea having low plasticity. The results can be utilized for the evaluation of the long-term settlement of the embankment in the future. But as indicated by the reviewer, readers may be confused because this paper does not include the results of long-term studies. Therefore, in the conclusion, long-term, creep, and related to long-term behavior have been excluded and the conclusions have been revised in overall.

Reviewer 2 Report

See the attachment

Comments for author File: Comments.pdf

Author Response

Authors appreciate sincere comments.

According to the comments, the manuscript was revised.

Author Response File: Author Response.pdf

Reviewer 3 Report

The construction problem presented in the paper does not only Korea. When building high-speed railways, the issues of consolidation and subsidence of land are very important for the safety of rail transport. Therefore, I consider the research on embankment materials according to fines content using sand and kaolinite to be very valuable. Experimental studies have shown inter alia the optimum fines content where induces low settlement would be 15 to 20% for the sand-kaolinite mixture.
The conclusions are of a practical nature and suggest further directions of research in this field.

Comments
The Authors also noted the expected creep settlement processes.
Title: suggests research describing "Effect of Fines Content on Long-term Compressional Behavior for Embankment Materials".
The conclusions are formulated:
1. "It could be assumed that the presence of kaolinite clay at a certain amount (15 and 20%) provides a significant effect to reduce the creep settlement in case of well-compacted condition".
2. "Therefore, this range of fines content was defined as optimum fines content (fopt) at which minimum creep settlement is expected".
3. "Furthermore, consolidation settlement and longterm settlement of the mixture should be investigated using granular compression index (Cc-s)".

Paper does not include the results of long-term studies. If the Authors believe that such studies are not needed, the conclusions should be formulated unambiguously or the title should omit "Longterm".

Author Response

The authors appreciate the reviewer’s valuable comment. This paper aims to investigate the effect of fines content on overall behavior of sand-kaolinite mixtures which can represent the embankment materials in South Korea having low plasticity. The results can be utilized for the evaluation of the long-term settlement of the embankment in the future. But as indicated by the reviewer, readers may be confused because this paper does not include the results of long-term studies. Therefore, in the conclusion, long-term, creep, and related to long-term behavior have been excluded and the conclusions have been revised in overall.

Round 2

Reviewer 2 Report

The author has solved all the problems readers asked. English is great. It is suggested to accept the paper. 

Wish success!