Resurfacing Performance Evaluation of Recycled Mixture with High Content of Iron Tailings Sand
Round 1
Reviewer 1 Report
This is an interesting experimental research carried by the authors to investigate the performance of recycled mixtures with high content of iron tailing sand, the following notes were recorded:
1- Authors need to list the total number of samples used in this article in the abstract as well as in the description of experiments. you may check :
2- Authors need to expand more in literature review, check the following reference and other references listed inside it.
3- In Line 75 Fe2O3 is not included in the ITS technical indexes, and the total composition is less than 100%.
4-Please clarify, in Table 6, the overall composition is less than 100%, however, you included two cementitious components (ITS and Cement) in Line 92 please specify.
5- In Table 7, How did the compressive strength increase from 6.8 MPa at 7 days to 61.2 MPa at 28 days? are you sure ( 10 times ? ) if yes, what is the reason ?
6- In Line 102, the ratios from ITS and RAI are 50%:50%, 60%:40%, and 70%:30%, although the RAI gradation in Table 3 is Fine and coarse. In contrast, ITS is gradation Fine. how to mix ratios from ITS and RAI.
7- The total number of drop times for each layer is 98, as shown in Lines 117 and 118. At what standard?
Author Response
I am so sorry to keep you waiting so long. I have attached the Revised Manuscript. Would you please check?
Point 1: Authors need to list the total number of samples used in this article in the abstract as well as in the description of experiments. you may check DOI: 10.3390/buildings13010132.
Response 1: For each group, every 2/6 mixtures were tested to get specific data. A total number of 380 mixtures were tested. And the total number of samples used in this article has been added to the abstract as well as in the description of experiments.
Point 2: Authors need to expand more in the literature review, check the following reference and other references listed inside it.DOI: 10.1016/j.treng.2022.100140.
Response 2: More literature review has been described in previously published papers(Dong Y, Zhang H, Hou Y, et al. Study on Mechanical Properties of Recycled Mixture with High Content of Iron Tailings Sand [J]. Advances in Materials Science and Engineering, 2021. https://doi.org/10.1155/2021/7658444). And the previous research on the mechanical properties of the recycled mixture has been added. Would you please check it in the attachment?
Point 3: In Line 75 Fe2O3 is not included in the ITS technical indexes, and the total composition is less than 100%.
Response 3: The XRF test has a lot of data, this paper only shows the main important components. The specific test data can be seen in the following figure. The Fe2O3 accounts for only 8.28 %, so it is not shown.
Point 4: Please clarify, in Table 6, the overall composition is less than 100%, however, you included two cementitious components (ITS and Cement) in Line 92 please specify.
Response 4: The first half of the question is the same as respones 3. For last half of the question, as we all know, the composition of Portland cement mainly includes CaO, SiO2, Fe2O3, Al2O3, so it is not included.
Point 5: In Table 7, How did the compressive strength increase from 6.8 MPa at 7 days to 61.2 MPa at 28 days? are you sure ( 10 times ? ) if yes, what is the reason?
Response 5: Compared with normal portland cement, the density and specific surface area of special cementitious material are smaller, so the early strength growth is relatively slow. The later alkali excitation can activate the SiO2 in the sand to make it have micro-expansion characteristics, so that the cross-linking of the specimen is tighter, thus showing greater strength.
Point 6: In Line 102, the ratios from ITS and RAI are 50%:50%, 60%:40%, and 70%:30%, although the RAI gradation in Table 3 is Fine and coarse. In contrast, ITS is gradation Fine. how to mix ratios from ITS and RAI.
Response 6: The cement-stabilized aggregates can fit the superior and inferior limits of grading. Considering that there is no research or report on this recycled mixture(RAI+ITS), this study breaks the traditional gradation limit and studies the mix design of the recycled mixture with high content of iron tailings sand. And just as the data shows, the recycled mixture has excellent pavement performances.
Point 7: The total number of drop times for each layer is 98, as shown in Lines 117 and 118. At what standard?
Response 7: According to the Test Methods of Materials Stabilized with Inorganic Binders for Highway Engineering T 0804-1994 (JTG E51 -2009). It has been added in the proper position.
Reviewer 2 Report
1. Title is hanging. “Resurfacing Performance Evaluation of Recycled Mixture with 2
High Content of Iron Tailings Sand”. Performance Evaluation for which field? Pavement? Concrete?
2. Abstract. Background study, problem statement, points out research gaps, aims & objectives, summary of methods, and novelty of research study are not clearly presented.
3. Introduction. Literature reviews not enough information, especially related to the Recycled Mixture study, more review is compulsary. Some paper suggestion as follow: (a). Ming et al. 2022. Performance of glass powder as bitumen modifier in hot mix asphalt. Physics and Chemistry of the Earth 128 (2022) 103263.; (b). Al-Saffar et al. 2021. A Review on the Durability of Recycled Asphalt Mixtures Embraced with Rejuvenators. Sustainability 2021, 13, 8970.
4. Table 1 to Table 6. Description and discussion is required. Not only data presenting.
5. Why ITS and RAI blending ratios used up to 50%:50%, 60%:40%, and 70%:30%? What is the reasonably?
6. Fig.7(b) not clear figure.
7. What the correlation Carbon Emissions with the main title? Not clear and mystifying.
8. Page 7, lines 192-196.not necessary, remove.
9. Lack of discussions for section “3.1.1”, “3.1.2”, “3.2”, and “3.5”. Only data presented.
10. Correlation of Carbon Emissions Estimate with aims of study is unclear.
Author Response
I am so sorry to keep you waiting so long. I have attached the Revised Manuscript.
- Title is hanging. “Resurfacing Performance Evaluation of Recycled Mixture with High Content of Iron Tailings Sand”. Performance Evaluation for which field? Pavement? Concrete?
Response 1: The recycled mixture is a new basement material, and it can be used in the base course and subbase. In other words, using it to replace cement-stabilized aggregates is feasible.
- Background study, problem statement, points out research gaps, aims & objectives, summary of methods, and novelty of research study are not clearly presented.
Response 2: The abstract has been improved, would you please check it in another attachment?
- Literature reviews not enough information, especially related to the Recycled Mixture study, more review is compulsary. Some paper suggestion as follow: (a). Ming et al. 2022. Performance of glass powder as bitumen modifier in hot mix asphalt. Physics and Chemistry of the Earth 128 (2022) 103263.; (b). Al-Saffar et al. 2021. A Review on the Durability of Recycled Asphalt Mixtures Embraced with Rejuvenators. Sustainability 2021, 13, 8970.
Response 3: More literature review has been described in previously published papers(Dong Y, Zhang H, Hou Y, et al. Study on Mechanical Properties of Recycled Mixture with High Content of Iron Tailings Sand [J]. Advances in Materials Science and Engineering, 2021. https://doi.org/10.1155/2021/7658444). And the previous research on the mechanical properties of the recycled mixture has been added. Would you please check it in the attachment?
- Table 1 to Table 6. Description and discussion is required. Not only data presenting.
Response 4: The materials used can meet the design requirements, and the materials involved in this paper are conventional pavement materials, so in my opinion, it is not necessary to do too much discussion.
- Why ITS and RAI blending ratios used up to 50%:50%, 60%:40%, and 70%:30%? What is the reasonably?
Response 5: ITS is mostly in the form of fine-grained soil, and is mainly deposited in tailings ponds. According to the statistics, nearly 2 billion tons of ITS exist in China, and the annual discharge exceeds 75 million tons. The water contained in iron tailings sand is often rich in a variety of agents, and the large number and volume of tailings sandbanks not only occupy a large amount of land space and pollute the environment, but also exist chemical hazards. Therefore, the original intention of this paper is to consume as much of these discarded environmentally harmful solid waste materials as possible. In addition, the utilization of ITS is not more than 30 % in past research, so this paper considers the design from 50 %.
- 7(b) not clear figure.
Response 6: Fig. 7 ( b ) is a screenshot of the computer connected to the UTM. Please zoom and you will see it clearly.
- What the correlation Carbon Emissions with the main title? Not clear and mystifying.
Response 7: Because this paper is about the road performances of the recycled mixture, the ultimate goal is to apply it to engineering. In addition to the low-carbon concept in recent years, the carbon emission is estimated.
- Page 7, lines 192-196. not necessary, remove.
Response 8: Page 7, lines 192-196 have been removed.
- Lack of discussions for section “3.1.1”, “3.1.2”, “3.2”, and “3.5”. Only data presented.
Response 9: The specific analysis for sections “3.1.1”, “3.1.2”, “3.2”, and “3.5” have been written in another paper ‘Dong Y, Zhang H, Hou Y, et al. Study on Mechanical Properties of Recycled Mixture with High Content of Iron Tailings Sand[J]. Advances in Materials Science and Engineering, 2021.’ https://doi.org/10.1155/2021/7658444. Furthermore, those results are relatively clear at a glance. So this paper just only quotes.
- Correlation of Carbon Emissions Estimate with aims of study is unclear.
Response 10: This paper considers almost all the links in the application of engineering and conducts on-the-spot investigations in engineering. Therefore, the estimation of carbon emissions of the two materials studied in this paper is believed to be credible.
Reviewer 3 Report
Dear Authors,
the article concerns the use of recycling waste such as iron tailings sand (ITS) and reclaimed inorganic binder stabilized aggregate (RAI) for the construction of road surfaces. The research is based on a road resurfacing project in Shanxi Province, China, and it proposes the “ITS plus RAI” double waste treatment technology.
Evaluated the pavement performance of the recycled mixture by testing its antiwater damage, frost resistance (dry and wet freeze), shrinkage, and fatigue properties, and compared it with the corresponding pavement performance of cement-stabilized aggregates (the traditional base course material). As a result, it turned out that the recycled mixture has good road performance.
In my opinion, this is a very good article, dealing with the use of industrial waste from mining, the protection of the Earth's natural resources. Also noteworthy is the fact that it is possible to reduce CO2 emissions thanks to the use of this technology.
So, from my point of view, this is an interesting article and has a good scientific value. The article covers the policy of sustainable development of the world economy. Compared to other published materials, the topic is original.
The article requires some substantive corrections, as well as descriptions of figures and tables (units) and minor additions to the text. In the literature, attention should be paid to the separation of punctuation marks. Attached are the comments highlighted in yellow.
After supplements, I recommend this article for publication in Coatings.
Kind regards.
Comments for author File: 
Comments.pdf
Author Response
I am so sorry to keep you waiting so long. I have modified the chart format and attached the Revised Manuscript. Would you please check?
Round 2
Reviewer 2 Report
The authors only argue suggestions from reviewer. Thus, no improvement on the revised version. Reject is highly recommended.
