Introducing a Novel Concept for an Integrated Demolition Waste Recycling Center and the Establishment of a Stakeholder Network: A Case Study from Germany

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Demolition waste is the main component in the stream of solid waste disposed of in developed cities of the world and is formed as a result of the demolition of various structures and buildings. In this regard, the problem discussed in the reviewed paper is relevant not only for Germany, but also for other countries of the world and I think it deserves to be published. But at the same time, I would like to draw the authors’ attention to some aspects that, in my opinion, need to be reflected in the manuscript.

First of all, it seems to me that it is necessary to reflect the current state of the problem of recycling demolition waste in Germany and compare it with other countries.

Secondly, demolition waste contains many components. It is necessary to provide the composition of demolition waste. And what is supposed to be done with other waste components, for example wood, metal, glass, etc.

Thirdly, it seems to me necessary to cite the advantages and disadvantages of the proposed demolition waste recycling center and compare them with existing ones (the most successful waste management systems of other countries can be used).

Fourthly, the captions under Figures 1, 3 and 4 need to be expanded so that there is an understanding of what is being said without referring to the text.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

I compared  the problem of recycling demolition waste in Germany to other European countries in line 59 to 62 and line 67 to 75.

 

I included the problem of calculating the composition of demolition waste in l 62 to 63.

I added the treatment of other waste components, e.g. of wood in l 351 – 352 and included the recycling units in the DWRC concept for fractions such as  wood, metal, glass in line 358 and 359.

I added the limitations in regard to quantification of other CDW fractions in l 460 to 461.

 

Thirdly, it seems to me necessary to cite the advantages and disadvantages of the proposed demolition waste recycling center and compare them with existing ones (the most successful waste management systems of other countries can be used).

 

I mentioned current disadvantaged of existing recycling centers in l 297 to 303 ”Current systems suffer from logistical inefficiencies, such as disjointed operations across multiple locations and communication gaps between stakeholders. For instance, recycling companies typically receive construction and demolition waste from demolition sites and transport it to consumers after recycling, involving multiple intermediate steps [35-38]. This fragmented approach results in high transportation costs and environmental impacts due to repeated material handling and long-distance transportation.”

 

I compared the DWRD to other best practice projects in Europe in line 375-379 “Various best practice projects in different European countries [41-43] have also combined Research and Development (R&D) units at the same location as the recycling plants and have proven to support the economic prosperity [32]. Additionally, numerous best practice projects [44-46] incorporate various industries adjacent to the recycling plant, fostering synergies between material flows [32].”

 

 

                 

I added additional information to the  captions under “Figure 1. Results from a survey conducted among regional stakeholders demonstrating the demand for information and education on various topics circular economy (CE)“ ,

Figure 3 “Visualization of DWRC [47] including the location of administrative and research units, next to outdoor and indoor storage facilities (containers for input and output materials) and technical systems, such as a soil washing system and scale. A surrounding berm is incorporated to mitigate acoustic disturbances and potential dust emissions to safeguard the neighboring community.” and

Figure 4 “DWRC initiating process conducted during two projects "Circularity in the Built Environment" (2016-2018) and the follow-up project named "ReBAU" (2020 -2022). Various stakeholders were engaged, including owners, purchasers, municipalities, Ministry of Building Affairs, Ministry of Environmental Affairs, associations, recycling companies, and research institutions. Several outputs were produced throughout this process, including funding proposals, Letter of Intent [50], technical [31]and conceptual studies [32], and material testing.” need to be expanded so that there is an understanding of what is being said without referring to the text.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript titled "Establishing a Stakeholder Network for Integrated Construction and Demolition Waste Management" addresses an important issue in the construction industry regarding the underutilization of recycled aggregates for producing recycled concrete. The study investigates the reasons behind this lag through surveys and interviews with stakeholders, identifying miscommunication and high demand for information as critical factors. The proposed concept of a stakeholder network for an integrated construction and demolition waste center presents a novel approach to addressing these challenges by integrating recycling companies, construction product manufacturers, research, service, and educational divisions in one venue. The manuscript highlights the potential benefits of the proposed network, including logistical optimization and knowledge transfer. Overall, the manuscript provides valuable insights into improving the utilization of recycled aggregates in construction processes. However, to enhance the scientific rigor and impact of the study, further elaboration on the methodology, data analysis, and validation of the proposed concept is recommended. Additionally, discussing potential challenges and limitations associated with establishing and maintaining such a stakeholder network would provide a more comprehensive understanding of the proposed approach.

Author Response

 

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

 

I added further explanation to the methodology of the concept: “Furthermore, the strategic roadmap in Section 5.2 presents a chronological sequence of key actions for the DWRC's development. This roadmap is developed based on the authors' empirical insights and the developmental process acquired during two projects: "Circularity in the Built Environment" (2016-2018) and its follow-up project "ReBAU" (2020-2022), both funded by the European Regional Development Fund (ERDF). Primarily, the roadmap delineates the objectives, approaches, and outcomes for each phase of the process. Additionally, collaborations with various stakeholders and their respective outcomes are chronologically mapped and visualized in Figure 4.”.

I added additional information on the data analysis of the empirical research in 2.1. (see track changes).

I agree, that a  validation of the proposed concept would enhance the scientific rigor and impact of the study. However, a  validation of the proposed conception of the DWRC is pending, as a real-life application has not yet been implemented (added in line 178).

I mentioned potential challenges and limitations associated with establishing and maintaining such a stakeholder network in line 573 “ However, challenges and limitation in information exchange between stakeholders can occur [53] due to misinterpretations or loss [54]. Therefore, it is recommended moderate and support information exchange by establishing and maintaining a network through an independent institution.”

 

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript “Introducing a Novel Concept for an Integrated Demolition Waste Recycling Center: A Case Study from Germany” by Magdalena Zabek et al. have reported how to make full use of waste through a comprehensive and systematic approach. Especially, the work presents a novel concept of a stakeholder network for an integrated construction and demolition waste center, which owning relatively high originality. However, a minor revision is needed before acceptation. Here are some comments for this research work for further improvement of this work.

1. The title “Introducing a Novel Concept for an Integrated Demolition Waste Recycling Center: A Case Study from Germany” should be revised to further highlight the originality of this work. For example, I suggest the “stakeholder network” should be added in the title.

2. In the last three paragraphs of the introduction part, the sentence structure is somewhat confused and the introduction of this work is very inadequate.

3. the “7. Conclusion & outlook” part is too long, which should be shorten to highlight the originality and the promising prospects.

4. I suggest some figures and their captions should be central aligned.

5. Why the references in 2023 and 2024 are almost non-existent? I suggest some key references in 2023-2024 should be added.

Comments on the Quality of English Language

Quality of English Language is good which just needs minor editing.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

I added “stakeholder network” in the title “Introducing a novel concept for an integrated demolition waste recycling center and establishment of a stakeholder network: A case study from Germany”

 

I restructured the  last three paragraphs of the introduction part to make it better to understand (see track changes).

I shortened the “Conclusion & outlook” part.

I aligned some figures.  captions are placed according to the template.

I updated key numbers from natural aggregates, cement and rubble and added other construction waste such as iron, steel or timber with a  source from 2020 published in 2023. I added several other references with sources from 2023. However, none from 2024 as this is too recent.

Reviewer 4 Report

Comments and Suggestions for Authors

According to the plagiarism check, the title and the abstract have similarities with a website named: icrsconf.com. Therefore, a correction is required.

 

Under Introduction section it is stated that:

“…As the building sector is a material-intensive industry, millions of tons of raw materials and wastes are generated in Germany every year (e.g. natural aggregates = 477 Mt, cement = 27.5 Mt, rubble = 59.8 Mt)[7-9] Click or tap here to enter text..…”

The references 7, 8 and 9 have dates of 2018, 2019 and 2020, respectively. The one dating 2018 gives data for 2016. Are the numbers presented in the text (e.g. natural aggregates = 477 Mt, cement = 27.5 Mt, rubble = 59.8 Mt) are gathered from these references as averages? Is it possible to get data for natural aggregates, cement and rubble in these references? These facts should be clarified.

Also, the part “Click or tap here to enter text”, should be corrected.

 

In various parts of the manuscript one can find the following phrases:

“….Chapter 3 of this paper defines…”

“…..obstacles outlined in chapter 3 through surveys…”

“……The outlined initiation process in Chapter 5.1 can ….”

“…..plants in the RR are outlined in Figure 2, chapter 4.2…..”

These are not chapters but headings. Correction are required.

 

It is recommended to add a literature survey related to environmental impacts of using recycled aggregates.

 

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

I updated the title “Introducing a novel concept for an integrated demolition waste recycling center and the establishment of a stakeholder network: A case study from Germany” to avoid plagiarism.

 

I updated the numbers from a source dating back to 2020 and published in 2023 for  natural aggregates, cement and rubble and added other construction waste such as iron, steel or timber.

I erased  “Click or tap here to enter text”,

 

I changed chapters into headings in the text.

 

I add a literature survey related to environmental impacts of using recycled aggregates in l 60 to 62 “ However, the reduction of CO₂ emission associated with the use of RA compared to natural aggregate are minimal due to comparable emissions generated during manufacturing and processing [10].”

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Resource efficiency and the creation of a circular economy are pressing issues. In this regard, the issues discussed in the article affect a large layer of construction and demolition waste. I think the authors have done a lot of serious work and the information contained in the paper certainly deserves to be published and made public. After re-reading, I had one more question, which I think the authors should reflect in the paper. Is waste containing hazardous substances generated, and what should be done with such waste?

Author Response

Thanks for the revision and the valuable comments. I added in l. 339 tilll 341 additional information on hazardous waste : "Furthermore, it is essential to note that only non-hazardous waste is suitable for the production of recycled concrete (RC). Such waste materials must undergo appropriate treatment or disposal procedures. Notably, there is a dearth of data concerning the quantity of hazardous waste generated from power plant demolitions. "

Author Response File: Author Response.pdf