Research on Road Characteristics and the Microscopic Mechanism of Lime–Phosphogypsum-Stabilized Red Clay
Round 1
Reviewer 1 Report
This paper is about stabilization of red cohesive clay using both Lime and Phosphogypsum. The manuscript needs a major correction according to the following comments:
11) Page 2, line 76: the Subtitle is Red Clay but the color is yellow-brown? confusing and not clear?
22) Page 2, Table 1: What is Proportion (2.61)? Not clear.
33) Page 4, lines 123-124: According to ASTM (D2166/D2166M - 16), the length to diameter ratio of the soil specimen for Unconfined Compression Strength (UCS) should be between 2:1 to 2.5:1.? All UCS must be retested according to ASTM (D2166/D2166M - 16).
44) Page 4, section 2.3.2. Water Stability Test: Please, according to which standard this test was conducted? not clear?
5) The results and discussion should be scientifically presented. Needs revision.
The paper needs English proofread.
Author Response
https://susy.mdpi.com/user/review/displayFile/38831926/L4kEZmlF?file=author-coverletter&report=29266952
Author Response File: 
Author Response.docx
Reviewer 2 Report
The full text is logical and complete. However, there are still some shortcomings that need to be further optimized, and the recommendations are as follows:
1. the abstract of this paper is somewhat lengthy, and further streamlining is recommended;
2. what does the K in Table 5 represent in the paper, please mark it well;
3. there are relatively few references in the whole paper, please add some more references;
4. the micro-analysis part is not thorough enough, it is suggested to analyze more deeply;
5. the quality of English needs to be further improved, there are some places where reading is rather stiff.
The quality of English needs to be further improved, there are some places where reading is rather stiff.
Author Response
https://susy.mdpi.com/user/review/displayFile/38831972/yORa6u5I?file=author-coverletter&report=29267024
Author Response File: Author Response.docx
Reviewer 3 Report
2- Use some numerical results in abstract. Abstract is only qualitative.
3-line 45: what is “variation laws”?
4- lines 34-35 and 61-62 are the same.
5- line 64: “lime is used as a curing agent”. What do you mean?
6- line 74: mention the city and country of the place where the clay was taken.
7-line 84: Phosphogypsum was taken from what place or company?
8- Insert particle size distribution curve of clay.
9- Insert a picture of Phosphogypsum.
10- What are the chemical properties of Phosphogypsum? Insert a Table about that.
11- “The samples were cylinders with a height of 50 mm and a diameter of 50 mm”. Is the length/diameter ratio of the samples in accordance with Ref. [23]?
12- Based on which standards “Water Stability” and “Expansion” tests were conducted?
13-line 132: “integrity of the sample was observed” means?
14- Table 5: what is K?
15-line 135 and 136: insert pictures of ring knife samples and dilatometer.
16- what is + in line 152?
17-line 174: what is 2 cm3? You mean 2 cm3?
18- line 169: “The sample diameter was 61.8 mm, and the height was 20 mm.” insert a picture of this sample.
19-Table 6: why the unconfined compressive strength with 8% lime (1.38 MPa) is lower than 6% lime (1.39MPa) at the curing time of 7 days?
20- The results have not been discussed and they were only presented. For example: section 3.1 should be discussed more and the reasons and mechanism should be explained.
21- section 3.2 is only qualitative. Use some numeric results.
22- Change lines 246-254. They are obvious from figure. Explain the mechanism and reasons of this behavior.
23- Change lines 270-279. They are obvious from figure. Explain the mechanism and reasons of this behavior.
24- Explain and discuss section 3.5 more. It is not enough.
25- What are the application and limitation of your study?
26- The results should be compared with the previous works.
27- What devices were used for SEM and XRD?
1- English should be improved.
For example: line 9: “clay” is correct not “cla”.
Change lines 9 to 12: “these passed the ...red clay”. It is not clear.
Lines 40-43 are not clear.
Line 51: Tang et al. [13] is correct.
Line 54: Xu et al. [14-16] is correct.
Line 122: “Sample preparation was started after braising was completed” is not clear.
Lines 132-133: these lines are not clear.
Author Response
https://susy.mdpi.com/user/review/displayFile/38833033/5ZKmjn3c?file=author-coverletter&report=29279580
Author Response File: Author Response.docx
Reviewer 4 Report
miss letter y in line 9.
please add more reference that traceable by readers. seems all references are in chinese.
Author Response
https://susy.mdpi.com/user/review/displayFile/39051217/RF3UbHIW?file=author-coverletter&report=29441347
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The following comment has not been answered correctly. If the entire UCS is not retested, I have to reject the manuscript. Please carefully address the following comment in Version 1 of the manuscript. Please be noted that the L/D must be between 2 and 2.5
Point 3: Page 4, lines 123-124: According to ASTM (D2166/D2166M - 16), the length to diameter ratio of the soil specimen for Unconfined Compression Strength (UCS) should be between 2:1 to 2.5:1.? All UCS must be retested according to ASTM (D2166/D2166M - 16).
Author Response
https://susy.mdpi.com/user/review/displayFile/38831926/L4kEZmlF?file=author-coverletter&report=29783243
Author Response File: 
Author Response.pdf
Reviewer 3 Report
1-Fig.1 is wrong. It seems gradation curve of sand not clay!
2- Use a clear and close photo of Phosphogypsum. It is very far now.
3- The results have not been compared with the previous works about the topic.
4- The size of letters are not uniform. For example: the size of letters in Table 8 is very big.
1- English is still very weak. Improve the text. Just for example: rewrite lines 136-138, 270-275, 300-308, 310-313,385-386,410-412,265-270
Author Response
Revisions have been completed based on reviewer comments.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
No further comments
