Performance Study of Sustainable Concrete Containing Recycled Aggregates from Non-Selected Construction and Demolition Waste
, Mohammad Rahai 2 and Moses Karakouzian 3,*
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Authors，
Construction waste is a headache for countries at present, and studying and utilizing construction waste is a very useful research.However, there are still some shortcomings in the article that require further revision and adjustment.
1. From the innovation point of the article, there seems to be a problem. The article uses drilling to study the effect of soil from different times on the performance of concrete.After a period of accumulation of construction waste, some degradation may occur. Is it still necessary to remove the underlying soil and reuse it? From the perspective of cost and technology, is this method feasible?
2. The author has done a lot of work around the theme, but overall, the article is more like a technical report, lacking a deeper analysis of the data behind it. It can use element composition and microscopic methods to conduct in-depth analysis of relevant experimental impressions.
3. The article uses many abbreviations. It is recommended to list the abbreviations used in a table format for readers to further read.
4. In Table 2, both coarse and fine aggregates were made using recycled aggregates. What is the particle size distribution of the two? Please provide details.
5. In 4.2 section, Part of the experimental process should be a major window for understanding the experiment, and it is recommended to add more.
6. In Figure 7,three data cannot determine the trend line, it is recommended to increase the quantity of data.
7. The conclusion is too complex, it is recommended to reorganize it.
Comments on the Quality of English LanguageFurther grammar modifications should be made.
Author Response
- Reply to the comments of Reviewer 1
The authors sincerely thank the editor and reviewers for their valuable comments on our manuscript. With respect to the comments, the authors tried to respond to each of them separately. The answer to each comment has been given according to the number allocated to each comment by the reviewers. These comments are considered in the revised manuscript, and the changed portions of the manuscript are highlighted in Turquoise.
Reviewer #1: Construction waste is a headache for countries at present, and studying and utilizing construction waste is a very useful research. However, there are still some shortcomings in the article that require further revision and adjustment.
Comment 1: From the innovation point of the article, there seems to be a problem. The article uses drilling to study the effect of soil from different times on the performance of concrete. After a period of accumulation of construction waste, some degradation may occur. Is it still necessary to remove the underlying soil and reuse it? From the perspective of cost and technology, is this method feasible?
Response: Due to the growing number of the constructions in Karaj over recent 10 years, the generation rate of C&Dw has significantly augmented, so 6,000 tons of C&Dw is being produced daily in this city according to the statistics released by Karaj Municipality. Against this background, the present study aimed to analyze the recycled concrete mixes with the C&D aggregates from different regions of the unexploited waste landfill site in the Line 4 of Hesar. The use of non-selected C&D aggregates in concrete is a new issue and has innovation and no research has been done in this field so far. The issue of investigating the layers of construction waste depots to evaluate the reuse of these wastes is important from an environmental point of view and sustainability.
-We reuse non-selected constructed and non-selected demolition waste (C&Dw) in this research and not use soil.
-Considering that waste was used to produce concrete instead of some natural materials, the costs of materials will be much lower and preparing concrete using this method will be very economical. It should also be noted that preparing C&Dw from landfill does not require high technology and can be done easily.
-According to the evaluation made and the type of waste (concrete, brick, etc.), construction effect degradation is insignificant in this type of waste.
Comment 2: The author has done a lot of work around the theme, but overall, the article is more like a technical report, lacking a deeper analysis of the data behind it. It can use element composition and microscopic methods to conduct in-depth analysis of relevant experimental impressions.
Response: Based on your recommendations, this section was modified in the revised manuscript. A more complete description is provided in the various sections and microscopic images of the samples are provided in Figure 18 along with relevant descriptions.
Comment 3: The article uses many abbreviations. It is recommended to list the abbreviations used in a table format for readers to further read.
Response: Thanks for your comment, this section was added in the revised manuscript. All of abbreviations are mentioned in the first time they mentioned.
According to the journal format abbreviations defined the first time they appear in the manuscript in parentheses after the written-out form. The abbreviations has been modified as follows:
Construction and Demolition waste (C&Dw), Compressive strength test (CST), Modulus of elasticity (MOE), Wide wheel abrasion test (Capon test); British pendulum number (BPN); Ultrasonic pulse velocity (UPV); Boreholes (BHs); Test pits (TPs); Palm oil clinker (POC); Virgin aggregates (VA); Recycled concrete (RC); Concrete samples tests (CSTs); Test Pet (TP); Compressive strength class (C); Gigapascal (GPa)
Comment 4: In Table 2, both coarse and fine aggregates were made using recycled aggregates. What is the particle size distribution of the two? Please provide details.
Response: In 4.1 and C&Dw materials composition of the fine and coarse materials have been mentioned. Moreover explanation about particle size distribution of materials have been mentioned in figure 3 and related texts.
Comment 5: In 4.2 section, Part of the experimental process should be a major window for understanding the experiment, and it is recommended to add more.
Response: Based on your recommendations, this section was modified in the revised manuscript. Standard code and experimental procedures have been mentioned briefly in this section. More over Summary of the main laboratory tests and the Geotechnical characterization compare of C&Dw in present article with previous study have been mentioned in table 4.
Comment 6: In Figure 7, three data cannot determine the trend line, it is recommended to increase the quantity of data.
Response: According your comment, this section was modified in the revised manuscript. It should be mentioned that Figure 7 is Figure 8 in the revised manuscript.
Comment 7: The conclusion is too complex, it is recommended to reorganize it.
Response: Conclusion section has been reorganized and presented in a suitable way.
Quality of English Language: According to the reviewer's recommendation to edit the language of the article, native editing was done by Prof. Karakouzian, one of the authors of the article and from University of Nevada las Vegas.
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The authors appreciate the instructive comments of the reviewer. The authors also hope that they have been able to provide a satisfactory response to the comments made in the present manuscript.
With bests
Corresponding author.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe research team tackled a complex topic regarding the improvement of the quality of concrete used in construction using concrete formed from construction waste. Using high-performance analytical methods, they determined the composition of C&Dw and then made 33 concrete mixes with recycled C&Dw that were characterized using numerous specific tests.
The results obtained are satisfactory, demonstrating the practical usefulness of the experiment carried out in the laboratory. Of course, research can continue, this being a progress in the reuse and recycling of construction materials.
Author Response
- Reply to the comments of Reviewer 2
Reviewer #2: The research team tackled a complex topic regarding the improvement of the quality of concrete used in construction using concrete formed from construction waste. Using high-performance analytical methods, they determined the composition of C&Dw and then made 33 concrete mixes with recycled C&Dw that were characterized using numerous specific tests.
The results obtained are satisfactory, demonstrating the practical usefulness of the experiment carried out in the laboratory. Of course, research can continue, this being a progress in the reuse and recycling of construction materials.
Response:
The authors appreciate the comment of the reviewer.
To Improve the language of the article, native editing was done by Prof. Karakouzian, one of the authors of the article and from University of Nevada las Vegas.
With bests
Corresponding author.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis paper conducts various experiments to study the composition of C&Dw and the properties of concrete prepared using the C&Dw. Some results drawn from these experiments provide useful insights for engineers. However, there are several areas in the writing of the paper that need improvement.
1. The paper contains too many abbreviations, which may slow down the reading speed for readers who are not familiar with what these abbreviations represent. Please avoid unnecessary abbreviations. Additionally, define acronyms the first time they appear in the text and avoid redundant definitions.
2. The paper's overall structure is not well-organized. It is recommended to reorganize the structure of the article. It is suggested to remove Sections 2 and 3. In the "Introduction" section, introduce the research background, current research status, and the significance of this study. Add a new "Materials" section to introduce the sampling locations and composition of the C&D recycled aggregates.
3. Inconsistent Figure Labeling: There is inconsistency in how figures are labeled, with both 'figure' and 'fig' being used (e.g., on page 2, line 60, ' As illustrated in Figure 1'; on page 2, line69, '...as depicted in Fig. 1.'). This inconsistency may confuse readers.
4. Line 73 on Page 2: Correct "BNP" to "British pendulum number (BPN)"
5. Lines 99 and 122 on Page 3: Correct "course" to "coarse"
6. Line 252 on Page 8: Correct "table 4" to "Table 4"
7. Please pay attention to the superscripts of physical quantity units in the text. For example, in line 270 on page 8, it should be "kg/m3" instead of "kg/m3".
8. In lines 402 and 408 on page 15, it should be “R2” instead of "R2".
9. Lines 258-260 on Page 8: Correct "… was found to be 35-42%" to "… was found to be 35.42%". Correct "…16-17%" to "… was found to be 16.17%".
10. Lines 269-271 on Page 8: According to Table 4, the maximum dry unit weight of C&Dw in this study is 19.69 kg/m3, which should be less than the maximum dry unit weight of C&Dw in previous studies (around 21-28 kg/m3).
11. Please add the units for each physical quantity in Table 5.
12. The figure reference in the text is incorrect. For example, in line 429 on page 18, it should be Figure 11 instead of Figure 10.
13. The table reference in the text is incorrect. For example, in line 485 on page 20, it should be Table 8 instead of Table 5. Similar errors also appear in lines 500, 509 and 515 on page 22.
14. In Section 6.5, "Complementary tests, Capon abrasion resistance," for coarse recycled aggregates, as the content of coarse recycled aggregates increases, the groove width of concrete decreases. However, contradictory results were observed for fine aggregates. Could you explain the reason for this contradiction?
15. For the same physical quantity, please retain the same number of decimal places. For example, in line 539 on page 23, it should be "42.0% and 12.0%" or "42% and 12%".
Comments on the Quality of English LanguageMinor editing of English language is required
Author Response
- Reply to the comments of Reviewer 3
The authors sincerely thank the editor and reviewers for their valuable comments on our manuscript. With respect to the comments, the authors tried to respond to each of them separately. The answer to each comment has been given according to the number allocated to each comment by the reviewers. These comments are considered in the revised manuscript, and the changed portions of the manuscript are highlighted in Yellow.
This paper conducts various experiments to study the composition of C&Dw and the properties of concrete prepared using the C&Dw. Some results drawn from these experiments provide useful insights for engineers. However, there are several areas in the writing of the paper that need improvement.
Comment 1: The paper contains too many abbreviations, which may slow down the reading speed for readers who are not familiar with what these abbreviations represent. Please avoid unnecessary abbreviations. Additionally, define acronyms the first time they appear in the text and avoid redundant definitions.
Response: Thanks for your comment, this section was added in the revised manuscript. All of abbreviations are mentioned in the first time they mentioned. All of unnecessary abbreviations have been removed/
According to the journal format abbreviations defined the first time they appear in the manuscript in parentheses after the written-out form. The text has been modified as follows:
Construction and Demolition waste (C&Dw), Compressive strength test (CST), Modulus of elasticity (MOE), Wide wheel abrasion test (Capon test); British pendulum number (BPN); Ultrasonic pulse velocity (UPV); Boreholes (BHs); Test pits (TPs); Palm oil clinker (POC); Virgin aggregates (VA); Recycled concrete (RC); Concrete samples tests (CSTs); Test Pet (TP); Compressive strength class (C); Gigapascal (GPa)
Comment 2: The paper's overall structure is not well-organized. It is recommended to reorganize the structure of the article. It is suggested to remove Sections 2 and 3. In the "Introduction" section, introduce the research background, current research status, and the significance of this study. Add a new "Materials" section to introduce the sampling locations and composition of the C&D recycled aggregates.
Response: Thanks for your comment. According to this comment, section 2 and 3 have been removed from the manuscript and in the introduction section, research background, current research status and the significance of this study have been mentioned. New section “Materials” has been introduced and sampling location and composition of C&D materials have been mentioned.
Comment 3: Inconsistent Figure Labeling: There is inconsistency in how figures are labeled, with both 'figure' and 'fig' being used (e.g., on page 2, line 60, ' As illustrated in Figure 1'; on page 2, line69, '...as depicted in Fig. 1.'). This inconsistency may confuse readers.
Response: Thanks for your comment. According to comment, Inconsistent Figure Labeling was modified in the all text revised manuscript and all of Figure labeling mentioned in same format (Figure 1, Figure 2, …).
Comment 4: Line 73 on Page 2: Correct "BNP" to "British pendulum number (BPN)"
Response: Thanks for your comment. This section was modified in the revised manuscript.
Comment 5: Lines 99 and 122 on Page 3: Correct "course" to "coarse"
Response: Thanks for your comment. This section was modified in the revised manuscript.
Comment 6: Line 252 on Page 8: Correct "table 4" to "Table 4"
Response: Thanks for your comment. According your comment. This section was modified in the revised manuscript.
Comment 7: Please pay attention to the superscripts of physical quantity units in the text. For example, in line 270 on page 8, it should be "kg/m3" instead of "kg/m3".
Response: Thanks for your comment. This section was modified in the revised manuscript.
Comment 8: In lines 402 and 408 on page 15, it should be “R2” instead of "R2".
Response: Based on your recommendations, this section was modified in the revised manuscript.
Comment 9: Lines 258-260 on Page 8: Correct "… was found to be 35-42%" to "… was found to be 35.42%". Correct "…16-17%" to "… was found to be 16.17%".
Response: Thanks for your comment. In this part range of parameters have been mentioned. 35%-42% and 16%-17% are corrected in the manuscript and table 4.
Comment 10: Lines 269-271 on Page 8: According to Table 4, the maximum dry unit weight of C&Dw in this study is 19.69 kg/m3, which should be less than the maximum dry unit weight of C&Dw in previous studies (around 21-28 kg/m3).
Response: Thanks for the attention of the honorable reviewer. The specific weight range was between 19.69-21.3, the minimum value of which was resented in Table 4. This range was placed in the table completely (19.69-21.3).
Comment 11: Please add the units for each physical quantity in Table 5.
Response: Thanks for your comment. This section was modified in the revised manuscript. It is worth mentioning, some physical quality have not units (Cc=D302/(D10*D60), Cu=D60/D10).
Comment 12: The figure reference in the text is incorrect. For example, in line 429 on page 18, it should be Figure 11 instead of Figure 10.
Response: Based on your recommendations, this section was modified in the revised manuscript.
Comment 13: The table reference in the text is incorrect. For example, in line 485 on page 20, it should be Table 8 instead of Table 5. Similar errors also appear in lines 500, 509 and 515 on page 22.
Response: Thanks for your comment. All of table number have been checked in the revised manuscript.
Comment 14: In Section 6.5, "Complementary tests, Capon abrasion resistance," for coarse recycled aggregates, as the content of coarse recycled aggregates increases, the groove width of concrete decreases. However, contradictory results were observed for fine aggregates. Could you explain the reason for this contradiction?
Response: Thanks for your comment. This section was modified in the revised manuscript. Due to the fact that this part was not necessary and on the other hand, it was ambiguous, it was removed from the text of the article.
Comment 15: For the same physical quantity, please retain the same number of decimal places. For example, in line 539 on page 23, it should be "42.0% and 12.0%" or "42% and 12%".
Response: Thanks for your comment. According to your suggestions, this section was modified in the revised manuscript.
Quality of English Language: According to the reviewer's recommendation to minor edit the language of the article, native editing was done by Prof. Karakouzian, one of the authors of the article and from University of Nevada las Vegas.
The authors appreciate the instructive comments of the reviewer. The authors also hope that they have been able to provide a satisfactory response to the comments made in the present manuscript.
With bests
Corresponding author.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsSuggest receiving with the current version.
