Influence of Organic Content on the Mechanical Properties of Organic-Rich Soils Stabilized with CaO-GGBS Binder and PC

Round 1

Reviewer 1 Report

1) Are your all results, presented in the tables from 1 to 4 of the manuscript, the average of different runs?

2) In the section 2. Materials and Methods, please describe the methods and the equipments used to perform the tests presented in all tables

3) Add nomenclature to the manuscript

4) Please highlight the novelty of this study in your manuscript

5) What about the experimental conditions of all figures from 1 to 8

6) Compare and thoroughly discuss your results with the literature

7) The conclusion should be more quantitative

8) Literature review should be updated with a new reference related to the influence of organic content on mechanical properties of organic-rich soils stabilized with CaO-GGBS binder and PC

9) The English language of the manuscript should be re-approved by a native speaker.

Author Response

Dear reviewers & editor:

We appreciate you to review the manuscript “Influence of organic content on mechanical properties of organic-rich soils stabilized with CaO-GGBS binder and PC” (No. 1906740) and share your insightful thoughts, which will serve as a great guide for our paper and further research. We have been acutely aware of the flaws in the writing process after attentively reading the comments. The following are our replies to the comments of the two reviewers and the modifications made according to the specific suggestions:

Please note that the reviewers’ comments are shown in normal font and our responses are shown in italic fonts below.

 

Reviewer 1: (The main revisions are marked in blue in the manuscript)

1. Are your all results, presented in the tables from 1 to 4 of the manuscript, the average of different runs?

Response: The measured results of some parameters are average values, while others are not. The following is a detailed explanation:

Table 1: The natural moisture content is the average of the moisture content of three different blocks of the same soil, which are 28.72%, 29.34%, and 29.54% respectively. The Atterberg limits, including the liquid limit and the plastic limit, are not average values. The plasticity index, which is the difference between liquid limit and plastic limit, is also not the average value. The specific gravity was measured by a density bottle method according to ASTM D854-14 (2014), and the result is the average of two tests. The grain size distribution of the soil was measured by Mastersizer 2000 laser diffractometry, which result is not the average value. The pH of the supernatant is tested after mixing dry soil and pure water into a solution with a ratio of 1:2 for several hours. The pH of the supernatant shown in Table 1 is the average value after 2 h, 6 h, and 24 h.

Table 2: Table 2 shows the main chemical compositions of materials, which are measured by an X-ray fluorescence spectrometer (XRF) and are not average values.

Table 3: Table 3 describes the test scheme of this study, and does not involve the testing values.

Table 4: In this study, two parallel samples were prepared for each condition, and the deformation moduli E₅₀ under different conditions are the average values of the two parallel samples.

2. In section 2. Materials and Methods, please describe the methods and the equipments used to perform the tests presented in all tables.

Response: The detailed test methods and equipment of each parameter in Tables have been marked in blue handwriting. The specific locations are as follows:

Table 1:The natural moisture content (Line 97-99); The Atterberg limits (including the liquid limit and the plastic limit) and specific gravity (Line 99-102); The grain size distribution (Line 102); The pH value (Line 104-105).

Table 2: Line 111-112

Table 3: Table 3 describes the test scheme of this study. The contents and methods of samples under different conditions are shown in Section 2.3 Specimen preparation and test method (the unconfined compressive strength, Line 149-151; the moisture content and pH value, Line 154-156).

 

3. Add nomenclature to the manuscript.

Response: The method of different conditions in this study is mentioned in Section 2.2 Test scheme (Line 135-136). The sentence was marked in blue handwriting.

 

4. Please highlight the novelty of this study in your manuscript.

Response: We summarized the innovation of this study and add it in Section 1 Introduction and Section 4 Conclusion. To understand the novelty of this work, relevant content was marked in green handwriting in the manuscript. Following is a distillation of the novelty of this study:

• The feasibility of treating organic-rich soil with CaO + GGBS was studied and compared with PC. The strength development of the OM soil stabilized by different binders was obtained.
• Combined with the physical-chemical property tests and related literature, the influence of OM on two treated soils was put forward, and engineering suggestions were proposed.
• The advantages of CG and PC in treating organic-rich soil were discussed from the aspects of engineering and environmental benefits.

 

5. What about the experimental conditions of all figures from 1 to 8.

Response: In response to the reviewer's question, we listed the test methods and reference standards of data in each figure in this study below (Table 1).

Table 1 Testing methods and standards corresponding to each figure

No.	Testing name	Testing method	Testing standard
Figure 1		Show the appearance of each material in the study
Figure 2	UCS test	Take photographs of the damaged samples	ASTM D2166M-16 (2016)
Figure 3	UCS test	Test at a loading speed of 1 mm/min using a microcomputer-controlled electronic uni-versal testing machine (CMT4204)	ASTM D2166M-16 (2016)
Figure 4	UCS test	Extract the stress-strain curves of the failure process from the tests	ASTM D2166M-16 (2016)
Figure 5		Calculate the deformation modulus E50 of the samples according to the stress-strain curves and Eq. (1)
Figure 6	Moisture content test	Treated soils were dried in a 60 °C oven for 24h
Figure 7	pH test	Mix soil and pure water into a solution with a ratio of 1:2, then stand for several hours after measuring the pH value of the supernatant.	ASTM D4972-19 (2019)
Figure 8		Calculate the attenuation rate of strength according to Figure 3 and Eq. (7)

6. Compare and thoroughly discuss your results with the literature.

Response: The latest literature on cement-based materials for treating organic-rich soils is used to compare this study in terms of strength. To visualize the results of this comparison, new Fig. 9 and Table 5 are added in Section 4 of the manuscript. The relevant content was marked in blue handwriting. Fig. 9 shows the strength of cement-based materials for treating organic-rich soils under different conditions. Table 5 shows the comparison of different conditions for treating organic-rich soils.

 

7. The conclusion should be more quantitative.

Response: In Section 5 Conclusion, part of the expression has been modified to make the conclusion more quantitative. The relevant content was marked in blue handwriting.

 

8. Literature review should be updated with a new reference related to the influence of organic content on mechanical properties of organic-rich soils stabilized with CaO-GGBS binder and PC.

Response: Part of the literature has been updated to the last five years. All substitutive literature was marked in pink handwriting.

 

9. The English language of the manuscript should be re-approved by a native speaker.

Response: We invited experts with rich experience in English writing to revise the English expressions in the manuscript. The relevant modifications were marked in blue handwriting.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Try to revise spelling of some words, e.g. binger instead of binder on line 26.

Please specify what is the proportion of GGBS in the Cao-GGBS binder, what is the organic content of the soil? is the content of organic matter the total OM added to the mixture?.

On table 2 Silty Clay is the soil?, try to send all results to paragraph 3.

On table 6, there are empty spaces for otganic matter content such as CG20O6, this happens also with the binder content and curing age.

I would include paragraph 4 discussion in 3 results.

On conclusions on number 3 it says that "moisture content of two treated soils increases", but in Materials and methods there is only one soil that has been obtained from Nanjing Forestry.

 

 

Author Response

Dear reviewers & editor:

We appreciate you to review the manuscript “Influence of organic content on mechanical properties of organic-rich soils stabilized with CaO-GGBS binder and PC” (No. 1906740) and share your insightful thoughts, which will serve as a great guide for our paper and further research. We have been acutely aware of the flaws in the writing process after attentively reading the comments. The following are our replies to the comments of the two reviewers and the modifications made according to the specific suggestions:

Please note that the reviewers’ comments are shown in normal font and our responses are shown in italic fonts below.

 

Reviewer 2: (The revisions are marked in red handwriting in the manuscript)

1. Try to revise the spelling of some words, e.g. binger instead of binder on line 26.

Response: Thank the reviewer for the careful examination. We re-checked the English expressions and spelling in the manuscript and marked the relevant changes in red handwriting.

 

2. Please specify what is the proportion of GGBS in the CaO-GGBS binder, what is the organic content of the soil? is the content of organic matter the total OM added to the mixture?

Response: In Section 2.2 Test scheme, we specify that the weight ratio of CaO to GGBS is 0.25, which means CaO:GGBS=1:4 (Line 134-135).

The organic soils were synthesized and only one kind of OM was added, so the content of OM was the content of all OM in the mixture. In addition, it is noted that the OM content of the mixture is calculated relative to the weight of dry soil.

 

3. On table 2 Silty Clay is the soil?, try to send all results to paragraph 3.

Response: The Silty Clay in Table 2 is the soil used in this study. We have explained it in Section 2.1 Materials, and the relevant content was marked in red handwriting (Line 103-104).

In Section 3 Results and analyses, we have presented all the results except for Section 3.2.2. Stress-strain curves. The reason is that the purpose of Section 3.2.2 is to explore the variations of peak stress and failure strain of samples under different OM content and binder content, revealing the failure mode under different variables. The curing age has little influence on this variation law, so this section shows the stress-strain curves at typical curing age under different variables.

Under the influence of organic content, the samples with a curing age of 7 days were selected. This is because the binder was not fully hydrated at 7 days, OM was the main factor affecting the strength development. Under the influence of binder content, the samples with a curing age of 28 days were employed. This is because the PC-based materials can reach the designed strength after curing for 28 days, the cementation of hydration products is the key factor in the strength development.

 

4. On table 4, there are empty spaces for organic matter content such as CG20O6, this happens also with the binder content and curing age.

Response: We are deeply sorry for the misunderstanding caused by our typesetting of the form. Therefore, we redesigned the table to make each experimental condition clear and easy to understand. The relevant content was marked in red handwriting.

 

5. I would include paragraph 4 discussion in 3 results.

Response: The calculation results of the strength attenuation rate of CG/PC-treated soils were included in Section 4 Discussion into the fourth conclusion. The relevant content was marked in red handwriting.

 

6. On conclusions on number 3 it says that "moisture content of two treated soils increases", but in Materials and methods there is only one soil that has been obtained from Nanjing Forestry.

Response: The “two treated soils” in this conclusion means the CG and PC treated soils in this study, rather than the untreated soils.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The response to my comment 3 is not enough, please revise your response and reply to my comment exactly:

 Add nomenclature to the manuscript.

Response: The method of different conditions in this study is mentioned in Section 2.2 Test scheme (Line 135-136). The sentence was marked in blue handwriting.

 

Author Response

Thank you for your recognition of the first response letter and the revised manuscript. We apologize for not responding properly to third comment in the first response letter.

New response: Each test condition in this manuscript is named using the formula “binder type + binder content + organic content”. Among them, the binder types in this study are PC and CG (CaO + GGBS); the binder content is 10%, 15%, 20%, and 25%; the organic content is 0%, 3%, and 6%. Since samples with different types of binder, binder content and organic content all need to be treated for 7d, 28d and 56d, the variable of curing age is not included in the naming of conditions. When the effect of curing age is discussed, it is annotated in the text.

Here, we provide an example in order to aid the reviewer's comprehension. A sample containing 6% organic matter treated with 20% PC will be named “PCB20O6”.

We hope that our response will assist you in better understanding this study.

Reviewer 2 Report

Thank you for your research

Author Response

Thank you for your careful review again.