Uncategorized - Recreate

December 10, 2024

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As part of the ReCreate project, WP7 plays a pivotal role in developing circular business models for concrete reuse, contributing to the overall goal of establishing sustainable and economically viable practices in the construction industry. In this interview, key team members from Tampere University—Leena Aarikka-Stenroos, Mikko Sairanen, Linnea Harala, and Lauri Alkki—share updates on their progress, insights into co-creating business models, and the value propositions they’ve explored for expanding the reuse business across Europe.

Can you share some updates on what WP7 has achieved so far within the ReCreate project?

LEENA: Absolutely! We’ve hit two important milestones. First, we’ve mapped out how different countries approach the reuse of building materials, focusing on three specific cases. This has helped us understand how actors in the construction industry are involved in reusing concrete elements. Second, we’ve started developing business models that show how companies can profit from reusing concrete. Moving forward, we aim to keep refining our understanding of how these processes work across different countries to ensure the project’s success.

WP7 focuses on developing circular business models at both company and value chain levels. Can you explain how these business models are being co-created and how they contribute to the project’s goals?

MIKKO: We’ve created business model canvases to map out how companies can profitably reuse concrete. These canvases cover three levels: the overall system, individual company profiles, and specific process stages like quality control or storage. Different countries have slightly different setups. For instance, in Germany and the Netherlands, some companies manage most process stages from deconstruction to reconstruction, while in other countries, multiple companies handle different parts of the process. By analyzing and mapping these models, we help companies figure out how to make this approach profitable, both in the short and long term.

LEENA: I’d like to add that we’ve noticed a lot of variation in how these models work across different countries. Some companies only handle deconstruction, while others do both deconstruction and reconstruction, which affects their business approach. This diversity helps us understand how different roles and processes can be profitable.

Could you share some insights into the value propositions, value creation, and value capture strategies explored within WP7 for concrete reuse?

LINNEA: We found several ways that reusing building components can create value, either through cost savings or new revenue. Key factors include the design and condition of the donor building, location, logistics, and efficient project management. Regulations and industry acceptance of circular practices also play a big role in creating value.

LAURI: In the Netherlands, we saw that “one-on-one” reuse, where components are taken from one building and directly used in another, is the most profitable approach at the moment, but of course it requires a key actor who can take responsibility along the process from deconstruction to construction. Overall, in all pilot projects companies also gained new skills, especially in deconstruction and design, which are critical to enabling component reuse.

MIKKO: In Finland, making concrete reuse profitable is a challenge, especially due to high deconstruction labour costs. Success depends on strong regulations, efficient demand management, and clear strategies for reuse. The Netherlands and Germany are good examples of how to do this effectively.

LEENA: Learning is key. Companies may face higher costs at first, but as they gain experience in deconstruction and reuse, they become faster and more efficient, lowering costs in the long run.

One of WP7’s objectives is to identify strategies to expand the reuse business across Europe. Can you explain these strategies and how they deal with the local nature of the building industry?

LINNEA: We’ve considered the idea of creating a marketplace for concrete elements, which could help expand reuse. However, there are challenges in making this work locally and deciding who would manage and profit from it.

LEENA: Construction companies often work in different countries, and they can apply what they learn in one place to another. For example, a Finnish company in our project wants to use its new practices across all the countries they operate in. However, different countries interpret regulations differently, which can be a challenge.

LAURI: That’s a great point, especially since we have large companies like Skanska and Ramboll in the project. Sharing knowledge between countries is key, and some countries offer great examples for others to learn from.

How does the analysis of safety and health aspects translate into economic value within the concrete reuse ecosystem, and what measures are being considered to enhance safety and health in this context?

LEENA: Safety and health analysis is crucial but incurs costs, such as for quality checks and safe practices. We need efficient ways to integrate these assessments, potentially using digital technologies, to minimize expenses while ensuring safety, which is vital for economic value in concrete reuse.

LAURI: In our discussions with Skanska, safety concerns about reused concrete elements were prominent. It’s essential to communicate to customers that these elements are thoroughly tested and safe to build trust in the market.MIKKO: Brand reputation in construction hinges on safety and quality. Companies must meet these expectations to protect their image, making quality a critical aspect of our analysis.

LINNEA: Work safety regulations can vary, affecting project costs and feasibility. For instance, Germany has stricter safety standards compared to Finland, impacting deconstruction costs.

Can you elaborate on the connections between social and legal barriers and economic value within the concrete reuse business models?

MIKKO: Social challenges, like public trust in reused concrete, can influence demand and economic value. Legal barriers, such as product compliance and market access issues, also affect economic viability. Balancing these factors is essential for successful business models.

LEENA: The Finnish Ministry of Environment values expertise in creating supportive regulations for circular processes, aligning with our project’s goals to shape favourable EU and national legislation for component reuse.

LAURI: In Finland, there’s confusion over classifying deconstructed elements as waste or not, which complicates handling and permits. This uncertainty has caused delays in the pilot project.

LINNEA: Ownership of elements is vital; in Finland, construction companies retain ownership from harvesting to sale, simplifying the process.

How do you envision the role of technology, societal acceptance, and regulatory factors in shaping the economic aspects of concrete reuse, as discussed in Task 7.4?

LEENA: Technology, societal acceptance, and regulatory factors are interconnected in influencing concrete reuse economics. Advancements like automation and digital modelling enhance feasibility and efficiency. Societal trust in reused materials boosts demand, while balanced regulations are needed to support innovation without hindering business. Effective communication and marketing can foster societal acceptance, helping to increase demand for reused concrete elements.

WP7 focuses on identifying easily achievable improvements and economic benefits in concrete reuse. What are some of the “low-hanging fruits” that have been identified, and how can they accelerate the transition toward more sustainable building construction?

LEENA: We’re identifying simple improvements, or “low-hanging fruits”, that can promote concrete reuse. While still gathering data, we see that small changes can encourage companies to embrace reuse without a complete overhaul.

LAURI: A key improvement involves rethinking collaboration roles in construction. Embracing broader collaboration beyond traditional roles can significantly enhance concrete reuse efforts.

MIKKO: Effective data management and communication among all parties are crucial. Knowing where deconstructed elements will be reused and planning accordingly can optimize the entire process.

In your journey with the ReCreate project, could you share a memorable experience or moment that has had a significant impact on your perspective or approach to sustainable construction and circular economy initiatives?

LINNEA: As a doctoral researcher, my most impactful experience was visiting the German cluster, where I saw how cost-effective building component reuse transformed old elements into new spaces. It was enlightening.

LEENA: A key moment for me was realizing the potential of concrete reuse in reducing emissions and seeing the project’s problem-solving spirit that drives sustainable improvements.

MIKKO: Visiting Lagemaat in the Netherlands was eye-opening; seeing their profitable concrete reuse operations changed my perspective on feasibility in this area.

LAURI: My memorable moments include witnessing the Lagemaat operations and the progress of our Finnish pilot project, both highlighting the project’s impact.

In summary, WP7’s efforts within the ReCreate project are forging a path toward a more sustainable and economically viable construction industry through the development of circular business models for concrete reuse. The insights gained from diverse country analyses, coupled with innovative strategies for collaboration and technology integration, underscore the potential for significant advancements in this field. By addressing safety, social acceptance, and regulatory challenges, the team is not only enhancing the viability of reused concrete but also building a robust framework for future circular practices. As these initiatives continue to evolve, they hold the promise of transforming the construction landscape across Europe, making it more resilient and environmentally responsible.

by ReCreate project

September 27, 2024

Written by Linnea Harala & Lauri Alkki

The ReCreate pilot projects in Finland, Sweden, Germany and the Netherlands highlight diverse approaches to implementing concrete element reuse, each influenced by unique building types, contexts and organizational structures. An initial analysis by ReCreate’s business research work package (WP7) has revealed distinct patterns in these approaches, primarily categorized into centralized and decentralized models. During the ReCreate annual meeting in Zagreb, WP7 also organized a workshop to present the identified approaches to other project partners and to get feedback on the initial analysis.

Figure 1 & 2. Workshop between ReCreate partners at the annual meeting in Zagreb on the preliminary results of the two different approaches.

The identified approaches – A) centralized & B) decentralized

The centralized approach is characterized by a single key actor managing multiple phases of deconstruction and reuse. This model is most prominent in the Netherlands. There, the same actor is responsible for deconstructing a building and reusing most of its elements in a new structure, a process referred to as 1-on-1 reuse. The ecosystem in a centralized model is simple, with a central hub managing all operations. The key actor controls the flow of information and data mostly internally, ensuring streamlined communication and decision-making. In addition, the key actor’s business model extends to both deconstruction and reuse, highlighting its capabilities and resources. A strong single actor can oversee the entire project, facilitating optimized and controlled execution. With one key actor at the helm, there is a clearer distribution of tasks and responsibilities. On the other hand, success depends heavily on the performance and capabilities of the key actor.

Conversely, the decentralized approach involves multiple specialized actors managing different phases of deconstruction and reuse. This model is evident in Finland and Sweden, where elements are harvested and reused in various buildings. The ecosystem in the decentralized approach consists of several specialized, complementary companies and organizations. Therefore, effective communication and data sharing between these actors has been identified as a critical factor for success. In the decentralized approach, each actor operates based on its expertise and specialization, contributing to a more diversified and flexible business landscape. The feasibility of the decentralized model depends on how well the project organization coordinates multiple companies. This complexity requires robust inter-organizational collaboration to ensure smooth transitions between phases, as multiple actors require more discussion to define responsibilities at different stages, at least initially.

Overall, it can be seen that in the centralized approach, the control of the dominant key actor can streamline operations, but it relies heavily on this actor’s capabilities. On the other hand, the decentralized approach, while more complex, offers flexibility and the potential to leverage a wider range of expertise. In both approaches, the work phases and tasks are largely the same, but their overlap and sequence may vary. Ultimately, understanding these approaches allows for better strategic decisions throughout the concrete element reuse process, promoting more sustainable and efficient construction practices.

by ReCreate project

July 5, 2024

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.

by ReCreate project

December 13, 2023

Christoph Henschel, BTU

In conventional architectural projects, the use of the building and the design concept typically determine the dimensions of the structure. This means that the height of spaces, as well as the width and length of rooms, are defined by what will happen in them once they are built. Constraints on the size of a building are usually only imposed by limited budgets, the site and its context, or zoning laws. All of this changes drastically when reused precast concrete comes into play. Suddenly, the structure dictates the spatial dimensions, the grid size or the floor heights of the building design. This changes the design task for the architect and presents new challenges. In order to show that these challenges are also full of opportunities, the following text describes the design process for the German pilot project within the ReCreate project, a youth center for the town of Hohenmölsen.

The design task began with a detailed analysis of the elements that could be salvaged from the donor building. Specific types, dimensions and available quantities of exterior and interior walls and ceiling slabs were determined. Preliminary tests of the concrete strength and examination of the reinforcement properties ensured the suitability for reuse in advance. With this catalogue of elements as a starting point, the design process for the new building could begin – always with the goal of using as many reused elements and as little new material as possible.