Studying Thermal and Mechanical Properties of Recycled Concrete by Using Ceramic Aggregate

Round 1

Reviewer 1 Report

This manuscript evaluates the “Thermal properties of recycled concrete by using ceramic aggregate”. The manuscript is elaborately described and contextualized with the help of previous and present theoretical background. All the references cited are relevant to this area of research. The methods/analytical study are clearly stated. The result and discussion section are clearly presented. The manuscript needs Minor revision and require the following modifications before the acceptance.

1. Title needs to be changed a bit. Author studied the mechanical properties also. But, title reflect thermal properties alone. Also, the word ceramic is mis spelled in the title.

2. What is the research need? Mention it in the abstract. Mention the your research recommendation in the last line of abstract.

3. Cite the sentence ‘For most developing countries, they also face the problem of over exploitation of natural resources, a huge number of solid wastes have been produced, and  more than 30% of the total solid waste is construction and demolition waste (CDW)’ with more works. Some are found below.

https://doi.org/10.1016/B978-0-12-821730-6.00031-0

https://doi.org/10.3390/ma15124272

https://doi.org/10.1002/suco.201800355

4. Cite the sentence ‘The demand for environmental protection and energy conservation have made the  appropriate design and construction of buildings with lightweight materials’ with more literatures. Some are found below.

https://doi.org/10.12989/sem.2022.83.3.387

https://doi.org/10.1016/j.conbuildmat.2021.123209

5. Include the experimental photos of the various test done.

6. Fig 2. (b) X axis title – Change the strength to compressive strength. (c) There is a spelling mistake in y axis title. Do the same correction in Fig.3 also

7. Compare your results with existing studies.

8. Present your research recommendations at the end of conclusion part.

Author Response

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Reviewer 2 Report

Thanks to the authors for their interesting paper.

Please find some comments below:

 

Line 106: “Refer to Table 4, five groups of mixes were prepared by using a different 106 percentage of ceramsite (0%, 30%, 50%, 70%, and 100%),” the replacement percent of ceramsite is based on volume or weight? Please clearly explain the criteria for calculating the amount of sand, aggregate and ceramsite in Table 4. Give an example calculation as well.

Author Response

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Reviewer 3 Report

The paper is about the use of ceramic aggregates and fine recycled aggregates in concrete components. Mechanical and thermal performance of studied components are assessed by authors.

Authors should cite in the introduction other relevant references, e.g. many RILEM reports and other studies relating the use of ceramic aggregates in concrete.

The calculation of thermal parameters should be moved to the section Methods. In this way in the section results authors should present only the results obtained.

Table 2. the porosity of natural aggregates seems to be very high

Table 3. check the clay content, there is a typing mistake

I suggest presenting some pictures of the recycled aggregates (ceramic and fine) used in the study.

 

Because thermal performance is the core of the study, authors should collect data from literature of similar components and compare them with their own experimental results.

In my opinion this should enrich the discussion and show readers the advantages of what they are proposing.

Author Response

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Reviewer 4 Report

This paper presented an experiment study of thermal properties for concretes using recycled fine aggregates. Specimen preparation and experiment process was first introduced for measuring the thermal properties. It's found that the thermal and mechanical properties of the concrete is closely correlated with the replacement ratio. Overall I think this is a well-prepared paper with clear hypothesis and conclusions. Therefore, I'd recommend accept in the current form. Some miner comments authors can consider to further improve this paper: 

1. The indent of all the figures does not match the paragraph or tables. Please fix the format if possible. 

2. In the conclusion, it would be better if author can add short summaries of this work besides the conclusions. Also, what are some other possible future works? 

Author Response

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Round 2

Reviewer 2 Report

Thanks to the authors for choosing this interesting subject. The paper is well written but there are still some points that need the authors’ attention:

 

1-      Grammatical errors throughout the paper should be modified.

2-      Line 15: “A total of five concrete mixes (including a reference mix) were prepared with different levels of ceramic aggregate (0%, 16 30%, 50%, 70%, 100%).” Percentage by weight of volume?

3-      Line 73: “particle-shaping method [42], two-stage mixing approach [43], fiber and nano materials addition [44-45], the effects of the above methods on the performance of recycled concrete have been discussed.”  The importance of this paragraph for your paper is unclear and the sentence is irrelevant.

4-      Line 96: “Table 2. Physical properties of natural aggregate” what is the importance of water absorption/1h for the mix design calculation? Please explain it in the paper. This is relevant to Table3 and Tables 1 and 4 as well.

5-      Line 124: “?? and ?? represent the fine aggregate and coarse aggregate of 1m3.” The sentence is unclear. Is it weight?

 

6-      Line 166: Please explain the possible reasons for the negative influence of the ceramic aggregate on the concrete strength. What are the possible causes? Why should the lower density of ceramic aggregate decrease the concrete strength? Please discuss the relevant causes and parameters in the paper.

Author Response

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Reviewer 3 Report

The Thermal performance is the core of the study. In my opinion authors
must compare their own experimental results with data from literature.

This does not require much time and can be done in Fig. 7 

Author Response

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Round 3

Reviewer 2 Report

Thanks to the authors for improving the paper. However, the paper modification based on comments 4 and 6 can mislead the readers. I strongly suggest the authors provide relevant references for their claims.

Line 28: “The use of ceramic aggregate in combination with recycled fine aggregate has excellent environmental and economic benefits.” What does excellent mean? It is not appropriate to use such a vogue word in the abstract section and also in the conclusion section (line 348).

Line 100: “the greater the water absorption of the aggregate, the more loose its internal structure, the weaker the bond strength of the transition zone with the cement mortar interface.” Higher water absorption of aggregate means more mixing water absorption by the aggregate, reducing the bleeding at the interface, decreasing interfacial porosity, and improving the transition zone.

The authors claim that a weaker bond transition zone needs further attention and relevant references.

I strongly encourage the authors to add relevant references to the paper for any claim (in line with my opinion or against it). Please don’t give a claim without appropriate references. 

Line 188: “Low density of concrete indicates high porosity, its internal structure is relatively more loose, the hardness of concrete is also poor, and the bond strength of the transition zone of the cement mortar interface is weak, it is easy to form stress concentrations at the weak point when damaged by pressure, resulting in reduced concrete strength.” Why is the bond strength weak? The high porosity of the ceramic aggregate (and its high-water absorption) decreases the w/c ratio at the interface, improving the transition zone strength.

Moreover, please provide relevant references for these explanations.

 

 

Author Response

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