News - Recreate

figure9-1280x717.png

Project and industry partners involved:

BTU Cottbus-Senftenberg: Prof. Dr. Angelika Mettke, Viktoria Arnold, Jakob Fischer, Christoph Henschel,
Sevgi Yanilmaz, Anton Leo Götz

IB Jähne: Peter Jähne, Milena Zollner

ECOSOIL OST: Dietmar Gottschling, Bernd Mathen, Jens Muschik, u.a.

Figure 1 – 3D Model of the test building (Source: BTU)

The objective for the test construction was to generate findings on the practicability of the construction method by reusing precast-reinforced concrete elements. The reassembly and disassembly of the test building was carried out by and in cooperation with the German ReCreate industry partner ECOSOIL. In particular, the combination of used reinforced concrete elements with timber stud walls was to be tested, as well as the new steel connectors developed as part of WP5. A new filling mortar was tested for its applicability to form the butt joints between the precast concrete elements.

Figure 2 – Donor Building Type WBS70-C before deconstruction (Source: BTU)

The donor building for the test building was a five-story WBS 70-C apartment block on Karl-Marx-Straße in the small town of Großräschen in Brandenburg. A partial demolition was carried out here as part of a refurbishment project, in which the upper 2 or 3 stories were deconstructed. From the deconstruction mass, 12 precast concrete elements were transferred to Cottbus for the test building: 3 exterior wall panels, 6 interior wall panels and 3 ceiling panels (see Fig. 3) after they had been selected and marked in the installed state.
The element-oriented deconstruction began in November 2023 and was completed at the end of February 2024. The dismantled precast reinforced concrete elements were stored on the construction site in Großräschen for another month before being transported the approx. 40 km to Cottbus in April 2024.

Figure 3 – Overview of elements needed for the test building (Source: BTU)

Figure 4 – Floor plan of the test building (Source: BTU)

When designing the test set-up, an attempt was made to reproduce as many different element connection situations as possible. These include corner connections between two concrete elements or between a concrete element and a timber stud wall (corner connector), longitudinal connections between two concrete elements (longitudinal connector) or the centred connection of a concrete wall element with a concrete element installed at right angles (T-connector) – see Fig. 5 and 6.

The newly developed connectors are made of 8 mm thick flat steel and are attached to the top of the wall elements with concrete screws. The connectors can be fixed in both concrete and wood and are therefore very suitable for combining these two building materials. The steel connectors mounted on the top can be embedded in the mortar bed required for the ceiling elements anyway, so that they do not present any structural obstacle and are also protected against the effects of fire and corrosion.

Figure 5 – 3D Models of the newly developed connectors (Source: BTU)

Figure 6 – Placement of the steel connectors in the test building (Source: BTU)

In addition, the design concept of the test building was planned in such a way that a wall element and a ceiling element were to be cut to size in order to test the effort involved in sawing the concrete and whether the cut precast concrete elements could be used as intended.

The former airfield in Cottbus, which had been decommissioned for several years, was chosen as the location for the test building. There was sufficient space, a load-bearing concrete slab as a base and a suitable access road for the delivery of the reinforced concrete elements.

In March 2024, work began on the production of the timber stud walls and the setting of the masonry calibrating layer to prepare the construction site for the installation of the concrete elements. The used concrete elements were delivered to the construction site on April 18 and 19 and stored in the immediate vicinity of the test building. They were professionally reassembled within two days. Each wall element was placed on the calibrating layer (see Fig. 7, center), leveled and secured using mounting braces (see Fig. 7). The elements were joined together using the above-mentioned flat steel connectors. The use of the innovative SysCompound joint mortar (based on fly ash and recycled aggregate) was tested for the butt joints between the concrete elements. Various formulations for the SysCompound were developed and tested in the laboratory in advance. The bond between the old concrete and the fresh joint mortar was of particular interest. In this respect, not only the mortar strength played a role, but also the shrinkage behavior of SysCompound in comparison to commercially available joint mortar mixtures.

Figure 7 – construction process of the test building (Source: BTU)

Figure 8 – construction process of the test building (Source: BTU)

The assembly of the test construction went smoothly and quickly (see Fig. 8) so a positive conclusion can be drawn for future pilot projects. The flat steel connectors have proven successful due to their simple fastening by means of screws (assembly) and disassembly; the combination of reinforced concrete and timber stud wall elements has proven to be practicable and the sawn concrete elements could be reassembled without any problems.
From a planning point of view, it is recommended that larger dimensional tolerances of the concrete elements be taken into account, as the actual geometric dimensions sometimes deviate from the planning and the edge zones of the dismantled concrete elements are no longer level in some cases. Concrete sawing work is known to be feasible but should be reduced to a minimum due to the high costs and energy required. When filling the joints, it turned out that due to unevenness or broken edges and corners of the concrete elements – as explained above – significantly more grout was required in some cases than assumed in the planning.

Figure 9 – Aerial view of the test building after completion (Source: C. Busse + S. Karas)

Overall, the test construction on the former airfield site in Cottbus was a complete success. The BTU team would like to take this opportunity to thank the landlord DLR for the space used, the skilled workers from ECOSOIL and the logistics service provider Auto Klug. Without the cooperation of the aforementioned parties, the realization of the construction project in this form would not have been possible. In mid-May 2024, the test building was dismantled/disassembled again and transported away for temporary storage at a recycling yard 42 km away. If the used concrete elements are not requested as components for reuse, they will be recycled and are therefore still available through material recycling.


June 28, 2024
Dizajn-bez-naslova-42.png

Marcel Vullings – TNO

CROW is a Dutch organisation that gather and uncloses knowledge which is relevant for civil works and buildings. CROW officially launched the CROW-CUR Guideline 4:2023 “Reuse of structural precast concrete elements” on Tuesday (11-06-2024). This guideline provides a practical description of a working method that can be used in projects involving the reuse of structural precast concrete elements. It covers various aspects, such as preparations for deconstruction, the disconnection of elements, the temporary storage of elements, the assessment of rewon elements and the reuse of these elements in new structures. The guideline has a general section that covers topics that apply to reuse of all types of precast concrete elements. In addition, it has annexes in which specific products are highlighted . Currently, there are two annexes: annex A deals with reuse of hollow-core slabs and annex B covers precast prestressed bridge girders. More types of elements are going to be added to the guideline in the near future. The guideline is for both infrastructure and buildings, in the broadest sense of the word. Many aspects are the same for both, and the non-standard aspects are dealt with in the separate annexes.

TU/e, TNO and other experts, including contractors, engineering firms, clients and testing companies, contributed their knowledge, experiences and insights to shape the guideline. In this respect, the knowledge and experiences from the pilot projects of the Horizon 2020 project ReCreate were very valuable. The wide-ranging scope of ReCreate has helped shape all the guideline’s sub-sections.

CROW launched the Guideline on site at IJmuiden. Heidelberg Materials hosted the event and after presenting a quick overview of the guideline for a mixed audience, we all got a chance to check out the temporary storage (near Heidelberg Materials) for the harvested precast concrete bridge girders. Here, the girders are waiting to be used in new bridges at various locations in the Netherlands.

Hergebruik constructieve prefab betonelementen – CROW


June 20, 2024
Antti-Lantta-.png

Antti Lantta, project manager (building demolition), Umacon & Juha Rämö, technology director, Consolis Parma

The earth’s carrying capacity is being tested, and it cannot sustain the growing use of virgin natural resources on the scale required by the current economic and population growth. The most acute environmental damage of our time results from global warming and the loss of biodiversity.

The built environment is of great importance for an ecologically sustainable society, as the construction sector globally consumes about half of all the world’s raw materials and causes about a third of greenhouse gas emissions. From the perspective of a circular economy, there is a huge potential here.

This includes the EU-funded four-year international research project ReCreate (Reusing prefabricated concrete for a circular economy), which studies the reuse of concrete elements, which are deconstructed from buildings slated for demolition, in new construction. Umacon, a top demolition expert, and Consolis Parma, Finland’s leading manufacturer of precast concrete elements, are also involved in the research project.

Umacon renews demolition industry in Finland

The prevailing demolition method in Finland focuses on material recovery, where the secondary raw material materials created through demolition are used in the recycled or otherwise utilized, for example in earthworks. Reusing whole precast concrete elements is rare, even though valuable building parts and equipment, such as building services components, industrial machinery and steel or wooden columns and beams, have been salvaged in Finland in the past. Until now, deconstruction has been driven more by the resale value of building components and equipment than the goal to reduce carbon dioxide emissions.

The reuse of precast concrete elements has not been implemented on a larger scale in Finland before. For Umacon, environmentally friendly and sustainable construction is part of its business values, so applying for the ReCreate research project was a natural choice. The work phases of the deconstruction project had to be planned in a new way so that the elements would not be damaged during the deconstruction work. During the project, new working methods and methods for detaching and lifting elements were developed to ensure that the deconstruction takes place safely and efficiently. Efficient working methods were refined as the project progressed. For example, it took four weeks to deconstruct the elements of the topmost floor, but the last floor was completed in just five working days! The key to a successful project was combining an array of different working methods that had been tried and tested in previous demolition projects into a functional deconstruction process.

Umacon wants to renew the demolition industry in Finland and become a leading company in the deconstruction sector. The success of the ReCreate research project shows that deconstructing precast concrete elements as intact is technically possible. By steering legislation towards low-carbon construction and improving the productivity of deconstruction, deconstruction will mainstream in Finland. Deconstruction and construction are teamwork that require the cooperation of all parties to achieve the goals.

New business for element manufacturer Consolis Parma

Consolis Group is committed to the targets set out in the Science Based Targets initiative. The Group’s global goal is to achieve zero emissions by 2050. The Finnish Consolis company Parma aims to reduce emissions by five per cent annually and halve them by 2035. The most significant means for reducing emissions are the increased use of low-carbon concrete elements, energy efficiency, and the circular economy.

Parma’s low-carbon products are based on substituting cement with binders from industrial side streams. In addition, crushed concrete is utilised in place of virgin aggregates. In the future, one possibility is to supply fully recyclable elements alongside new low-carbon concrete elements.

In the ReCreate research project, the reuse of whole elements is focused on in real life. The elements salvaged from the donor building in Tampere have been delivered to Parma’s Kangasala factory, where they undergo a quality check as well as the necessary modifications and equipment for reuse. The elements that have now been reclaimed were originally manufactured at the company’s factory in Ylöjärvi, Finland, and thus Parma is involved in a research project to promote the reuse of the elements it has manufactured itself.

In this kind of new business, the role of an element manufacturer may include, for example, design, quality control, dimensional changes and equipment, as well as other functions that are suitable to perform alongside new production at the precast concrete factory. Issues to be studied that deviate from new production include approvals, processes and logistics (deconstruction of elements, transfer to the factory, factory-refurbishment measures, transfer of elements to a new site and installation of elements) and environmental permit practices.


June 12, 2024
Dizajn-bez-naslova-41.png

In June 2024, the ReCreate project reached significant milestones with two pivotal meetings held in Zagreb, Croatia. Hosted by GBC Croatia, these gatherings brought together partners, and experts to discuss progress, share insights, and plan future actions in our mission to revolutionize the construction industry through sustainable practices.

Consortium Meeting: 5th June 2024

The consortium meeting on the 5th of June was a vibrant assembly of all project partners. The event provided a platform for members to review the project’s achievements, address challenges, and align on upcoming objectives.

Highlights of the consortium meeting included:

  • Project Progress Updates: Each partner presented detailed updates on their contributions and advancements, showcasing the collective progress made since the last gathering. The emphasis was on the general status of the project management, communication and dissemination activities, and the status of the each project pilot.
  • Technical Discussions: In-depth discussions were held on the latest innovations in reusing precast concrete elements, highlighting technical challenges and solutions of each project pilot in Sweden, Finland, The Netherlands, and Germany.
  • Collaborative Workshop: Interactive workshop fostered collaboration among partners, focusing on differences, as well as advantages and disadvantages in centralized and decentralized pilot approaches.
  • Future Planning: During the meeting, partners outlined the next phases of the project, setting clear goals and timelines to ensure continued momentum and success.

Review Meeting: 7th June 2024

Following the consortium meeting, the review meeting on the 7th of June brought together WP leaders and external reviewers. This critical session aimed to evaluate the project’s progress against its objectives and deliverables.

Key aspects of the review meeting included:

  • An assessment of the project’s achievements to date, including a detailed examination of technical milestones and deliverables.
  • External reviewer Helena Granados Menéndez provided valuable feedback, highlighting strengths and offering recommendations for improvement to ensure the project’s success.
  • Discussions focused on the broader impact of the project on the construction industry and sustainability practices, emphasizing the importance of innovative solutions in real-world applications.
  • The meeting concluded with a clear roadmap for the upcoming months, emphasizing continued collaboration, innovation, and dissemination of results.

Both meetings were instrumental in driving the ReCreate project forward, reinforcing the commitment of all partners to transforming the construction industry through sustainable practices. We look forward to the next phases of the project with renewed energy and focus.

Stay tuned for more updates on our journey towards more sustainable future in construction.


DEBUT-NEWSLETTER.png

Are you ready to embark on a journey towards sustainable construction and innovation? We’re thrilled to introduce the debut edition of the ReCreate newsletter, your gateway to the forefront of sustainable construction.

In our inaugural newsletter, titled “Precast Revolution: Welcome to Our First Project Newsletter” you’ll delve into the heart of the ReCreate project. Discover how we’re transforming the industry by reusing concrete components and significantly reducing carbon footprints by up to 98%. Learn about our mission to close the loop on concrete utilization, deconstruct precast structures, and catalyze circular construction.

Meet the passionate individuals behind the ReCreate project and learn about our goals to revolutionize the construction industry. From engineers to designers, and everyone in between, get to know the dedicated team driving innovation in our first issue.

But that’s not all! Our newsletter will also feature insights from our real-life deconstruction pilots, offering you a glimpse into innovative approaches to sustainable construction practices. Dive into our virtual exhibitions for an immersive experience, exploring cutting-edge technologies and advancements in the precast industry. Additionally, access downloadable publications filled with valuable insights and information.

Excited to be a part of this journey towards a more sustainable future? Make sure you don’t miss out on our inaugural newsletter! Subscribe now to stay updated on all the latest news and developments in the precast industry. Join us as we pave the way for a more efficient, sustainable, and innovative tomorrow.

Don’t miss out on exclusive content, insights, and updates. Subscribe today and be part of the precast revolution!

Go to Contact us page and subscribe to the newsletter.


ReCreate-blog-post-1.png

Tove Malmqvist Stigell, Senior Researcher and Docent, KTH Royal Institute of Technology 

A transition towards a more circular economy is currently lined up by multiple ongoing policy processes, not least within the EU Green Deal. One novel regulatory development already in effect in a few European countries is mandatory climate declarations and limit values on GHG emissions for buildings. What are these regulations and how do they connect to the re-use of precast concrete elements?

After several decades of development of LCA (Life cycle assessment) methodology for buildings aiming at guiding low-impact design in a life cycle perspective, a raised interest for building LCA has been seen during the latest years. Not least insights on the significance of embodied greenhouse gas emissions in buildings, has led to LCA-based regulations being introduced in several European countries. These require mandatory climate declarations of, so far primarily, new-build projects, and some of them also require building projects to display emissions below a set limit value. Such a climate declaration is a quantitative assessment of life-cycle related greenhouse gas emissions (GHG) of the building that the developer has to perform and hand in to the authority. Countries such as France, Sweden, Denmark and Norway already have such regulations in effect since 2022-2023. In France and Denmark limit values for these emissions are part of the regulation. Such limit values are represented by a set number of kg CO2-equivalents per floor area or per floor area and year, which can be tightened over the years to support further GHG emission reduction. Such limit values are also planned to be introduced in the coming years in Sweden and Finland. The Netherlands introduced a more comprehensive LCA-based declaration with limit value already in 2017. At EU level, the recast of the EPBD (Energy performance of buildings directive) requires a mandatory climate declaration for new-build from 2027 for buildings over 2000 m2 and from 2030 for all buildings, and similarly the EU taxonomy stipulates such a declaration from 2023 for buildings over 5000 m2. 

In the light of this type of regulatory development, the interest for developing methods to implement re-use of building components in new-build has increased much. The reason for this is that reuse of components could be one, among other strategies, to ensure low-carbon designs and to comply with tougher limit values in similar regulations. This since re-used components in general have lower environmental impact than virgin ones. To incentivize such strategies further, the Swedish regulation, as an example, makes it possible for a developer to use re-used products “for free”, that is count them as zero impact in the stipulated climate declaration. When setting up the mandatory climate declaration, the Swedish regulation requires a developer to make us of generic data from the national climate data base of Boverket unless EPD´s (environmental product declaration) exist and are used (and also verified that these products were procured to the building at stake). Reused construction products in Boverkets database are however currently allocated zero GHG emissions, thus incentivizing reused products in new building design This is naturally a simplification for to create an incentive, but since EPD´s on re-used building components are still extremely rare it would in the current situation not benefit re-use of precast concrete elements to require more detailed information on e.g the emissions of the reconditioning processes. Meanwhile, this type of information is currently built up in the ReCreate project based on the demonstrators in the project. 

A central issue of significance in the design of building LCA studies, including the method of LCA-based regulations, is the coverage of processes, that is the system boundaries for the assessments. It is often necessary to omit certain processes due to lack of data or to focus the assessments on known hot-spots. When these types of assessments now enter regulation, different countries take slightly different approaches to the choice of system boundaries which has led to discussions regarding how they then incentivize, or not,  certain low-carbon strategies such as circular solutions. For example, the Swedish regulation focus the production and construction stage impacts, that is the embodied GHG emissions of modules A1-A5, according to the European standard EN 15978. In a life cycle perspective, these emissions constitute a significant, and earlier non-regulated, hot-spot. These emissions can also be verified by the completion of a building project, compared to emissions associated with the use and end-of-life stages of buildings. Principally, one could argue that such a more narrow system boundary increase the incentives for re-use of precast concrete elements since the emissions of modules A1-A5 in contemporary construction of buildings are much dominated by the materials of the structure. If implementing more of a whole-life system boundary, as for example is planned for in Finland, the proportional impact of modules A1-A5 will be less, which might reduce the incentivizing effect of re-using building components. 

A well-known obstacle to reuse today is the difficulty, and thus the high costs, of dismantling buildings for reuse of elements and components with a viable service life left. This is a question that often comes up in connection to building LCA, with the idea that including the end-of-life (module C) and benefits and loads beyond the system boundary (module D) in the assessment system boundary would incentivize measures taken for design for re-use, including design for disassembly (DfD). However, end-of-life emissions associated with pre-cast concrete elements are much lower compared to emissions associated with the production stages (modules A1-A3) of contemporary construction in the European context, and it may thus be questioned to what extent it´s inclusion could have an incentivizing effect.  

An aim with module D is to give room for displaying future potential benefits in form of emission savings due to e.g reuse of components in new constructions, to be reported separately according to the EN 15978 standard. It should be noted that module D highlights potential future savings, the extent of which depend on the future handling of the components, which is hard to predict. The prospects for future re-use improve with DfD implemented, but the calculation of module D is not linked to whether such design strategies were implemented or not. Finally, one needs to remember that both module C and D deals with assessment of potential emissions in a distant future, thus their assessment becomes very uncertain. Normally, these assessments reflect today´s technology, but an increasing number of voices promote that decarbonization scenarios should be applied in similar long-term assessments. If so, the significance of module C and D also decrease. 

The proposed Finnish regulation is an example of a more comprehensive system boundary. It for example introduces thecarbon handprint which more or less reflect an assessment of module D to, in quantitative terms, visualize potential future benefits of re-using the components of the studied building along with other potential benefits of implemented design strategies

So to sum up, the emerging climate declaration regulations in various European countries do create new incentives to apply re-use of prefabricated concrete elements in today´s new-build. However, to for increased implementation of DfD strategies in today´s new-build for improving prospects for future re-use, these types of regulation do not provide direct and clear incentives. Instead, complementary steering mechanisms might be needed to promote DfD strategies

Resources: 

Boverket climate database in Sweden: https://www.boverket.se/sv/klimatdeklaration/klimatdatabas/  

Finnish emissions database for construction: https://co2data.fi/rakentaminen/#en   

Example of proposed ongoing regulatory development: the next steps proposed for the Swedish climate declaration regulation: https://www.boverket.se/en/start/publications/publications/2023/limit-values-for-climate-impact-from-buildings/#:~:text=Limit%20values%20can%20be%20introduced,on%20climate%20declarations%20for%20buildings  


Patrick-Teuffel.png

In this exclusive interview, we delve into the pioneering work of Patrick Teuffel, founder of CIRCULAR STRUCTURAL DESIGN, as he leads the charge in revolutionizing structural design for a circular economy. With a focus on sustainability and decarbonization, Teuffel discusses his role in the ReCreate project, shedding light on innovative approaches to integrating reclaimed precast concrete elements into new constructions. From reimagining design processes to the challenges and benefits of incorporating AI, Teuffel provides invaluable insights into shaping a more environmentally responsible future in construction.

1. Can you please introduce yourself a bit, your organization and your role in the project?

As founder of CIRCULAR STRUCTURAL DESIGN, I am strongly focused on advancing the principles of the circular economy and decarbonization within the built environment in the context of structural design. With my background as a structural engineer, I bring a strong combination of technical expertise and sustainability principles to my work. As an academic as well as professional, I am committed to revolutionizing traditional construction practices by integrating circularity and sustainability into every aspect of the design process.

In addition to my entrepreneurial pursuits, I also act as a professor specializing in Innovation and Sustainability Strategies at SRH Berlin School of Technology. In this role, I have the opportunity to impart my knowledge and passion for creating more environmentally responsible solutions to future generations of professionals. My advisory role at the DGNB (German Sustainable Building Council) Innovation Board and the circular construction team at Circular Berlin further underscores my dedication to driving meaningful change within the industry.

At CIRCULAR STRUCTURAL DESIGN, our mission is to seamlessly integrate the principles of circular economy and sustainable design into every structural project we undertake. Our approach is guided by three core principles:

1.) Minimizing waste and emissions: We prioritize minimizing resource consumption and emissions associated with our structures, ensuring that our designs have minimal environmental impact.

2.) Keeping products and materials in use: Our commitment to extending the lifecycle of materials, components and buildings drives us to promote high-level reuse and repurposing wherever feasible, thus reducing resource consumption and waste generation.

3.) Using renewable resources: In response to the ongoing depletion of finite resources, we actively explore and incorporate renewable material options whenever possible.

It is our mission to bridge the gap between research and practice and to integrate the principles of circular economy into everyday structural design projects.

Within the ReCreate project I am the lead of the WP5 that explores aspects of redesign and reassembly. I, as a structural engineer, focus on the implications for the design process and the actual technical and practical implementation in the context of the reuse of existing components.

2. Can you provide more information on your work package and how it contributes toward the project?

WP5 consists of two parts: redesign and reassembly. We explore design implications of the stock-based design and develop new connection types or put existing connections to the test to reconnect existing precast concrete elements.

Traditionally the design process follows a linear model. The building design is developed first and the required structural elements, that are needed to accomplish this design, will be manufactured from scratch according to the dimensions required for the project.
The whole work process needs to be rethought when it comes to reusing elements. When maximizing the integration of reused elements in a stock-based design approach, the traditional design approach of form-follows-function will be replaced by a new principle: form-follows-availability.

To enable the load-bearing reuse of existing components, connection details are required with which these can be reconnected. This is why the documentation of connection details that already exist and allow for an easy reuse and developing new connection details that will also allow for an easier future disassembly are the second focus point in WP5.

Perhaps the most interesting thing about the ReCreate project is, that these approaches are not only theoretically explored, but will be implemented in real live pilot projects. Hence a large part of WP5 is designing those pilots and sharing the lessons learned throughout the process.

3. Tell us more about task 5.1 on the framework of parameters for the development of the redesign and reassembly process for precast concrete elements in new buildings?

As stated, the design process is completely different from the status quo, when it comes to the integration of reclaimed elements. Here, the first step is to capture relevant information about the reclaimed precast concrete elements in order to know where and how those may be reused. So, the first thing you need to know is what those elements are. In task 5.1 we explore, what parameters and object properties need to be gathered and at what design stage different information needs to be available to enable architectural and structural design. Here, we are looking at typological and dimensional information and the structural capacity of the different elements.
This task closely interacts with other working packages, such as WP1: the analysis of precast concrete systems, WP2: the deconstruction as we are strongly interested in the shape and capability of each element after deconstruction, WP3: the logistics and processing and WP4: the quality management.

The knowledge gained through this process will be captured in a design guideline (deliverable 5.1) at the end of the project.

4. How does Task 5.3 highlight the challenges and complexities faced in the architectural and structural design process when reusing precast concrete elements?

Task 5.3’s focus is the understanding and developing of a design approach and actively implementing it in the design process in the pilot projects. The traditional approach of an architect developing a space concept first and an engineer designing the structural elements afterword to erect this space does not work when the pool of existing elements limits what they might be used for. Means: the design process needs to run “in reverse”. To understand the capability of the existing elements and what uses they can be put to, requires a close interaction of architects and engineers from the very beginning of the project.
Each country cluster approaches this separately and faces different architectural and structural challenges. Those experiences are discussed within the ReCreate project team and the experiences will be summarized in the form of a best-practice recommendation that incorporates the lessons learned from the project.

5. How does Task 5.3 propose to incorporate artificial intelligence (AI) and neural networks into the design process? What benefits are expected from using AI in this context?

When it comes to designing with reclaimed elements, different design approaches can be explored and different country clusters follow different approaches of how to start with a stock of reclaimed, prefabricated concrete elements and get to the finished product:  a building partially designed from those elements.
That insights gained and lessons learned will be gathered in a design manual that will be published as D5.1 at the end of the project.

Generally, the most straight-forward approach to designing with precast concrete elements is trial- and-error.

The larger the implicit knowledge about the reclaimed elements and reuse options are, the better the outcome will be.

Another possibility is a design optimisation aided by parametric design tools. Within the project research is undertaken how the design process can be aided by existing and newly developed design tools that allow for an optimisation.

Also, an AI-aided element matching between a pool of existing elements and a proposed new design will be explored. Especially when the list of reclaimed elements is very large, human trial-and-error can reach its limits. The AI-aided approach tries to do a first step by exploring a matching algorithm that highlights optimisation potential and best matches.

6. Can you tell us more on the processes and challenges that you are facing with the connections in task 5.2 and how do they influence the rest of your work? What are some of the risks that are present here? In the context of design for disassembly (DfD), how does Task 5.2 investigate the possibility of easier deconstructability in the new connections?

The feasibility and ease of new structural connections construction for reclaimed element has a large impact of the likelihood integration of reuse structural elements. In WP5 options to reconnect those structural elements will be explored. Particular attention is paid here to when the same connection points can be reused (with minor adjustments) during reinstallation. The connections that are to be used in the construction of the pilot projects are described. New connection types are also being developed in the project, those put a great emphasis on the possibility for a simple future deconstruction.
The general approach in the recreate project is, that both, new connection details that allow for an easier future disassembly are being developed in project funded university research studies. At the same time in the real life pilot projects conventional connection details that already exist, might also be used.

7. What is the relationship between the re-use of precast concrete elements and sustainability certificates, such as DGNB as discussed in Task 5.3?

When it comes to evaluating the sustainability of the reuse of precast concrete elements from an ecological viewpoint, two aspects can be highlighted. The reuse may help to save both finite resources and avoid new production emissions.
The topic of resource conservation in the context of a circular economy has recently come increasingly into focus, and green building certificates are trying to account for it. One example is here the the DGNB, where I am a member of the committee for lifecycle and circular design, the “DGNB Ausschuss für Lebenszyklus und zirkuläres Bauen“.

Important aspects such as reuse and deconstructability, which are addressed within WP5, are discussed here.

Additionally, a buildings carbon footprint is of course an important aspect to consider when it comes to evaluate the overall sustainability. Within WP5 internal meetings, the use of “LCA-as-a-Design-Tool” is repeatedly addressed. The goal is to actively identify and prioritize the lowest-emission design variant through regular design-integrated LCA (Life Cycle Assessment). Here we also closely collaborate with WP6.

8. How does Task 5.4 ensure a smooth implementation of the four real-life pilot projects, considering factors like transportation, supplementary materials, and equipment?

Let’s have another interview next year, then we can answer this question 😊

9. Who is Patrick Teuffel when he’s not working on the project and what does he like to do in his free time?

As for my personal preferences, I thoroughly enjoy engaging in sports like running and mountain biking, finding exhilaration in the great outdoors. Additionally, I have a passion for savoring good food, particularly exploring diverse culinary experiences. Living in the vibrant city of Berlin, I find immense pleasure in attending concerts and immersing myself in its dynamic cultural scene. Furthermore, I have a strong interest for exploration, fueled by my love for traveling and exploring the world, seeking out new adventures and experiences wherever I go. Last, but not least, I’m doing the final editing of this text in a spa – now you know where you can find me on a Sunday afternoon.


April 19, 2024
Paul-Jonker-Hoffren.png

We are privileged to continue our interview series featuring the talented individuals behind the ReCreate project. In this edition, we showcase Paul Jonker-Hoffrén, who focuses on policy issues related to circularity in construction and labor market.

Can you introduce yourself a bit, and tell us about your background and role in your institution and the project?

I’m originally Dutch, but I’m living in Finland. I have a background from the Netherlands in public administration and public policy research. It involves policy analysis studies and a bit of law in economics and sociology. However, until this project, I did not deal with it professionally. In Finland, I got my doctorate in labour sociology. In Finland, I’m working on labour market issues in labour market relations issues, such as relating to self-employment, the possession of labour unions etc. ReCreate Project to me is an opportunity to combine public administration and public policy research with labour market issues. In this project, I can focus on the policy aspects of circularity in construction as well as labour market issues. In my Work Package, we study work processes and the skills needed in the future to maintain the labour market for construction.

Can you provide an overview of your Work Package, its objectives and why are policy support and social acceptance important for reused precast concrete components?

My Work Package has two distinct things. The first one is about policy regarding circularity in construction and how those policies relate to legislation. The second is focusing on work process analysis. I’m not interested in how many people will be working in a circular construction, but I’m interested in studying how the work of current builders, architects and civil engineers would change through the idea of circularity. For some of them, things will change, and for some, it won’t. For example, for architects, we have to invent new methods. Regarding its objectives, they are here to make visible the policy environment in which this reuse happens and what kind of impact it has on work processes. 

It is important to know where the material comes from. If you think of demolishing whole city blocks of obsolete buildings and when you apply the ReCreate methods or any kind of reuse to that kind of scale then you also have to include the social aspects of this reuse because you have to have in mind that people who are living in those buildings have to go somewhere. Including all of this, social acceptability is important in the scalability of reuse because there has to be enough social support for this kind of urban renewal program.

What specific stakeholders are involved in the examination of legal possibilities and barriers at the EU, national, and local levels for the reuse of precast concrete components?

Our second deliverable in this Work Package answers this question, but it is not public yet. There is a lot of EU legislation on this and there are many directives which are involved. For example, the revision of the waste directive is now translated into National legislation and it will become active in 2028 or later. As this project ends in 2025 it won’t apply to us in that sense so at this moment we depend on National legislation. In the second deliverable, we have an overview of the valid norms for our four countries. It includes information on building permits, environmental law, work safety, waste issues and that kind of material standards (what kind of material should be used). 

At the local level, you have many different stakeholders in the legal policy environment and they vary a lot between our countries. That is because you have, on one hand- administrative rules, and on the other- responsibility for supervising construction safety.

How does the evaluation of social acceptability differ for the stakeholders involved in the circular value chain, including the impact on work and employment for the company stakeholders?

The social acceptability for stakeholders begins with profitability. For example, in Germany, there is quite a lot of experience with reusing concrete elements for various purposes. There are traditional DDR styles, big houses, but people are leaving because there’s a lot of free housing or empty housing- houses are too big. The solution was to cut off the top floors of this DDR building and make what was left into more modern and smaller housing units. Instead of crushing all the concrete and putting it on the roads or using it somewhere else, they use the elements to build new houses. 

Do you think that the part of Germany will be revitalized in a sense and that it will result in it being more desirable for people to move back there?

That is the idea. These new buildings are more desirable to live in. It seems that not a lot of people want to live in DDR flats anymore. If you look at reuse, especially in social acceptability, then the German case is specific on the topic of social acceptability because there is the former Eastern Germany and the migration away from there which causes an oversupply of housing. Finland has also noticed a kind of migration from small rural cities to the south of Finland or cities that have universities, but currently, it is not nearly at the scale of Germany. In the Netherlands, there are 50s and 60s housing estates which are not so desirable. The problem in the Netherlands is that there is not enough space. In terms of migration into the cities, there is an opposite tendency.

What are the key legal possibilities and barriers that need to be assessed concerning the reuse of precast concrete components throughout the circular value chain?

The key problem is, if you deconstruct a building, then those materials should not be wasted. In the EU we have end of waste status, which in Finland and Sweden is already implemented. If you deconstruct a building then you can apply for end-of-waste status. This means that it’s not building waste, but a potential new resource. It is very important in terms of legal and policy environment because as long the element is in the building there is no problem, but as soon as you take it out then it could be potentially waste and it is not reusable. In different countries, there are different routes to get to that status and it involves, in a very early stage, construction or deconstruction project leaders who have to be in contact with authorities that approve elements. You always need aspects like the structural characteristics of building materials that are acceptable and make sure that there aren’t hazardous substances. 

Other than that, there are not so many reasons why all of a sudden the same material should change its legal status from when it’s in a building or out of a building. Building materials should always be safe and good to use, if they don’t meet the standards then you shouldn’t use them. Authorities are not entirely sure how this works and what kind of test of building material it should require. This is what we do in ReCreate.

To get the national authorities to implement these practices that we are developing for the project, would it be easier to go and advocate this directly to the European Union, which would then modify the legislation and then send it to national legislation, or it is better and quicker to advocate it directly to National authorities?

Construction project regulation includes many of these things and it is such a document that National authorities have to refer to. Also, you have Eurocodes and similar industry norms. They have a national implementation, for example, climate. In Finland, you have higher snow load criteria than in Italy. It is not so much a lack of legislation, but more a question of what information the authority accepts and what information the authority requests. It is not only the skills of architects and engineers, but we also have to talk about the building inspectors who can check the building permit applications. 

How does this WP aim to systematically assess the social acceptability of the reuse of precast concrete components for the relevant stakeholders, particularly considering work and employment aspects?

That depends on the national circumstances. We are interested in the companies involved. Concrete-producing companies are involved in the project. In the Netherlands, there is a concrete agreement (kind of a sectoral agreement) on how to reach the emissions goals for that specific sector. At that level, I would say that they don’t have much interest in reuse because these other waste to reduce emissions are much closer to their normal production processes. This means if they can innovate, they can jump on the circularity train. Reuse, as we do in ReCreate, may be difficult for them because they’re standard way of doing business may be completely rethought.

Do you think that the market can add additional value to their business by buying older buildings (that no one wants to live in) for cheap prices and then selling these precast concrete elements for companies that want to use them?

That is one potential direction which is quite close to what the Dutch company is doing. The benefit of these concrete production companies is that they have so much information about their product, as well as all the equipment they need. I could envision that in the future these concrete production companies become kind of knowledge-producing, because in the processes that we have in ReCreate (and hopefully soon elsewhere) everything in the end turns on the availability of information because all the parties involved in the value chain need information. It’s still a bit unclear what exactly is the information needed at which stage. On the other hand, concrete produces can relatively easily produce all this information that is needed about the concrete elements. In that sense, I could imagine that if they start to move in that direction, instead of making concrete they could make digital twins of these older elements which have loads of information about them.

Do you have some intrinsic motivation for the ReCreate project and what motivates you to work on it? Do you think that we will achieve our climate goals by 2050?

I’m a bit pessimistic. I see a lot of potential here in this project. It is important that we can show all the methods, the materials and all the emissions impact of these pilots vs. normal buildings. But, if you want to make a difference you have to consider vast amounts of construction. For example, in the Rotterdam case, one consultancy firm used the kind of historical BIM model to estimate the amount of material that would be freed up from all the plant deconstructions in Rotterdam until 2030. Then you can make a big difference. The problem is, when you consider that kind of scale, you run into social issues. Calculations on paper are fine, but the point then becomes extremely political in the sense that someone has to decide what these materials are used for. That is a difficult problem because you have the municipality which has housing policies and interests on how much of what should be built; you have housing corporations which want to make money. In the Dutch case you can’t make much money with social housing, so technically or financially speaking they would probably build other than social housing except they are bound to build mostly social housing. For people who are living or want to live in the city, you have this kind of vague political pressure on what the housing market should look like, but there isn’t a right answer to that because it depends on which actor you are. Here you run into a political economy issue that, at best, is a compromise between different interests. In that way, I’m pessimistic because I see technical possibilities of these methods, but socially and politically is much more difficult than we may acknowledge.

Do you have anything else that you want people who read our website to know about your work package or yourself?

I think it’s very positive that also authorities are very pragmatic and they see that there is a connection between these abstract climate agreements and what they do. I always like to say that implementing circular construction is something which happens at the local level because in the end it is municipalities which sign off the building permits and they have local climate plans and housing plans for new and old areas. Even though we have great national and international plans and agreements, I think that important work is done at the local level by all the firms involved, civil servants and other authorities involved. It is important to remember that climate policy is not something that is somewhere out there, but it is really involved in local decision-making. 

I: To top it off – who is Paul Jonker–Hoffrén when he’s not working on the ReCreate project and when he’s not working at the University?

P: I’m interested in football. We have a summer cottage which I maintain. One of my main interests, apart from work, is music. When I have a free moment I listen to music. I used to play guitar and bass, but I switched to modular synthesis.

In summary, the interview with Paul Jonker-Hoffrén offers valuable insights into the intersection of policy, social acceptability, and circularity in construction. Through his expertise, we gain a deeper understanding of the challenges and opportunities inherent in the ReCreate project. Paul’s discussion highlights the importance of navigating legal frameworks, engaging stakeholders, and addressing social concerns to foster sustainable practices in the construction industry. His remarks emphasize the significance of local decision-making in driving meaningful change and advancing climate goals.


March 15, 2024
Inari-Weijo-Ramboll.png

Inari Weijo, business development manager (refurbishment), Ramboll Finland

During my master’s thesis work over 15 years ago, I familiarised myself with precast production and its history in Finland. After that, precast concrete has been playing a role in one way or another in my work career. Many projects have involved either repairing precast concrete buildings or building new ones. Since the 1970’s, precast concrete production has formed a significant part of the Finnish construction sector. The systematic and ‘simple’ method provided a standardized way to build, and it quickly became very widespread. The precast concrete system has been criticized for producing a unified stock of buildings, reducing versatility in urban environment and suppressing designers’ creativity. Since the early days, though, the technique spread to erecting ever more complex and monumental buildings. It has been foundational for providing a fast and trusted way for building construction in Finland. There are thousands and thousands of precast concrete buildings here, and some of them are already slated for demolition. A part of the buildings suffers from degradation, but many are just mislocated from today’s point of view.

Figure 1. Finnish deconstruction pilot in Tampere, building vacated before the deconstruction of elements for reuse.

I believe that technical know-how is essential for creativity and enables responsible and sustainable construction. We must be more aware of our decisions’ environmental impacts when building new. Architects’ and engineers’ creativity is ever more challenged as we must prioritize sustainability values. Knowing the technical limitations and possibilities is crucial, so that creativity can be unleashed in the right place at the right time, and adverse uncertainties can be eliminated. Building new is inevitable in the future too, but we need to redefine ‘new’. We must apply regenerative thinking, create net positive solutions and aim for more ambitious circularity. The actions we undertake should have a positive impact on nature and the environment so that instead of consuming it, they restore and revive it. This is a leading value for Ramboll.

Figure 2. Regenerative approach to construction. Image source: Ramboll.

The prevalence of precast technology and the aim for a regenerative effect on environment are two leading thoughts that that drive our ambition here at Ramboll to examine and challenge the present business as usual in the construction sector. The headline’s statement inspires me and my colleagues at Ramboll Finland when we seek to find alternative ways to utilize what already exists. The built environment is a bank of building parts that has technically perfectly fine components stocked in it, preserved intact inside buildings. Only processes and systems to utilize them effectively are needed. I sometimes face people itemising reasons and obstacles why reusing building parts is way too difficult. I believe this pessimistic attitude may well up from the insecurity that follows from the building sector changing dramatically. There may also be a disbelief whether the huge leap, which is necessary, can be taken. Some of the items that the sceptics list are well known, some are relevant, and some are just fictional. We need to keep solving them one by one, showcasing with real-life projects that this is possible and acquire more experience to narrow down the gaping hole between the ‘old’ and the ‘new’ way of building.

An important milestone has been reached when the Finnish cluster finished the deconstruction of the pilot building in Tampere this autumn. We succeeded to reclaim several hundred hollow-core slabs, columns and beams intact, ready for use on next building site. It’s been encouraging to gain good test results, both before deconstruction, through a condition investigation, and after deconstruction, as some of the deconstructed elements have been load tested. All has been well from an engineer’s perspective! Now, the reclaimed building parts are being fitted into prospective new building projects. The search for the new building site has not been stalled because of any technical issues but rather by the currently poor market situation.

That final issue to solve – an important one indeed – is the business model that can support reuse. A circular business needs more collaboration among all the players in the field. Technically we are ready to say ‘yes’ to reusing precast concrete elements!

Figure 3. Reclaimed hollow-core slab, deconstructed from the donor building in Tampere.


February 28, 2024
Jose-Hernandez-Vargas_ReCreate-blogpost.png

José Hernández Vargas

Architect and PhD student at KTH Royal Institute of Technology

A precondition for reusing precast elements is a correct understanding of the underlying logic of different building systems and the structural interactions between concrete elements. The analysis of existing precast systems starts with a thorough examination across multiple scales, as building layouts, individual elements and their connections are interdependent.

During ReCreate, several precast concrete systems have been identified and studied. While specific pre-demolition auditing and quality control are critical steps towards reusing concrete elements, this ordering of precast elements operates at an earlier and more abstract level, providing a knowledge base for known precast systems that may apply to multiple instances. This task attempts to provide an overview and develop guidelines for the further classification and digitalisation of precast elements as potential material for reuse. Moreover, the information gathered can serve as methodological guidelines for other systems that may differ from the studied cases but follow the same core principles.

When examining technical drawings from historical precast systems it is important to identify patterns that reveal the systematic ordering of the elements. This initial step involves identifying the underlying measurement system from the axes of the building, from which standard layouts can be inferred in discrete modules. Strict repetition patterns can often be found, especially in residential buildings, where building blocks are constituted by the repetition of a building module defined by a staircase. Similarly, this building module can be divided into residential units corresponding to the individual flats on each floor. Each unit defines in turn a defined arrangement of precast elements that can be precisely estimated for each building.

Thus, architectural and structural knowledge of precast buildings is essential for accurately estimating the building stock and potential for reuse of precast buildings. Given the economies of scale involved in this kind of building, the goal of this step is to build a knowledge base to establish workflows for the ordering and analysis of potential donor buildings for reuse.

Building scale

At the building scale, the analysis centres on the identification and classification of precast structures by structural principles and different building types. Precast buildings can be found in all sorts of applications. Yet, despite the wide range of structural solutions they predominantly follow a limited set of basic structural systems. The most prevalent structural frameworks for precast concrete include the portal-frame, skeletal structures, and wall-frame structures. Structural systems for arranging precast structural systems are closely linked to the building types they serve, responding to the intended program’s requirements. For example, portal-frame structures are most suitable for industrial buildings that require large open spaces. Conversely, for residential buildings wall-frame structures are more often the most cost-effective solution as load-bearing walls also separate living spaces. Beyond buildings completely built out of precast components, specialised subsystems can be found for facades, floors and roofs in combination with other structural systems.

System Skarne 66 (Sweden) and their main structural components form the original technical drawings (left) and as a digital 3D model (right)

Component scale

At the scale of individual precast elements, the foremost classification derives from grouping them by their structural role in the structure, i.e., as walls, columns, slabs, roofs, beams, foundations, and stairs that constitute the structure of the building. These categories are based on the Industry Foundation Classes (IFC) Standard (ISO16739-1), which provides a consistent framework for describing elements within the construction industry. These groups can be understood and modelled as variations of the same parametric object, akin to a family of building components. This process is key for building a comprehensive database of precast elements contained in each building.

To further understand the arrangement of elements that constitute a system, the overall dimensions of each element can be plotted to reveal the dispersion of distinct types within the system. In this example, all the elements are aligned in Cartesian space to define the largest dimension on each axis. This method allows the creation of a ‘fingerprint’ of each building, that shows a concise overview of the dispersion of element types and the individual quantities involved. Alignments resulting from common features such as floor heights and standard modules, can also be observed.

Comparison of the ‘fingerprint’ tool showing the types of elements used in System Skarne 66 (Sweden) and BES (Finland). Dot size indicates the number of elements of each type whereas colour corresponds to the main component categories.

Connector scale

At the connector scale, the different relationships between concrete elements can be related to force transfers and security features to ensure the correct and reliable transmission of forces. Connectors are key to ensuring structural integrity by managing structural loads while accommodating additional stresses and strains that arise from thermal movements, residual loads, seismic loads, and fire exposure, among others. A key aspect for evaluating the connectors is the assessment of the alternatives for disassembly and possibly reusing the connector. Analysing precast buildings at the connector scale allows the identification of the compatibility of precast elements across multiple systems from the analysis and comparison of structural details.

Ordering precast systems across these three scales provides a comprehensive picture of how precast systems are conceived, manufactured, and assembled. This knowledge is instrumental for understanding the possibilities that these elements offer for the next building lifecycle. This ordering will serve as the basis for classifying different precast systems into taxonomies and for the digitalisation of existing precast stocks as material for reuse in future projects.





EU FUNDING

“This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 958200”.

Follow us: