Erik Stenberg, architect and senior lecturer in architecture at KTH – School of Architecture and the Built Environment (ABE) in Stockholm, answered a few questions on why reusing concrete is important in urban development projects.
Why is the reuse of concrete important?
– This is where the biggest environmental benefits can be made. If you access the concrete in the structure of houses, you can achieve the largest reduction in carbon dioxide.
Why is it important in urban development projects?
– It is becoming more and more important to look at the entire life cycle and carbon footprint of the entire urban development and not just individual buildings. We have to look at what was there before and what will come after. We need to make better use of the resources that are already above ground. Also, the historical dimension has nothing to do with carbon dioxide pollution, but with cherishing a legacy, taking advantage of what is good and building on it, and improving what needs to be improved.
What are the benefits of using reused concrete?
– This is exactly what we test in ReCreate. The thesis is that the concrete continues to harden during its lifespan and the technical lifetime is much longer than the service life of the buildings. Therefore, reused concrete should be better than new concrete both constructively and environmentally as we do not use and extract resources from the earth’s crust.
So concrete is made to last longer than the time we use it today?
– It lasts much longer. The concrete you usually see is the one that is exposed outwards to the external elements and it is usually hit harder by rain, weather, cold, or salts (depending on where it is) than concrete that has been sitting hot and dry. If the concrete is hot and dry, it lasts forever.
What opportunities do you see when it comes to reusing concrete?
– I look at the material and historical values and that we get a healthier discussion about how urban development should be done, and that we consume fewer resources when we build in the future. This is the biggest change that needs to happen, not just thinking ‘new’ all the time but rather that we take care of what we already have.
Answering the challenges of tomorrow requires bold and visionary solutions and initiatives
H22is an ambitious initiative brought by the city of Helsingborg to develop future solutions directed at improving the quality of life in a smarter, more sustainable city.
That is why the initiative is organizing the H22 City Expo – an international event in Helsingborg that will run for 35 days and that will also serve as a platform for presenting innovative work and new solutions. The key focus of these solutions pertains to welfare and urban development, or in other words, how innovation can help improve the quality of everyday life for everyone living and working in Helsingborg.
H22 City Expo will gather the world’s visionary leaders and urban disruptors to explore local solutions for the global challenges that will define our future – and where cities must lead the charge.
Cutting edge technology, future homes, and the newest takes on a sustainable city will be heavily featured in the expo. Visitors and residents of Helsingborg will be able to interact with hundreds of innovative ideas and solutions and will also be able to put forth their own input! Each participant will be a living component in an urban lab that brings together industry leaders, public sector pioneers, and passionate residents to develop, share, and test real-life solutions in real-time.
ReCreate @ H22 City Expo 2022
Concrete is a big challenge for the climate and also one of the most important components of our buildings. The main goal of the ReCreate project is to introduce the concept of circularity into construction and to make the construction of new buildings and our future homes with reused concrete elements a viable option for the future of sustainable construction. It also examines the systemic changes needed throughout the construction process, from demolishing to the design of new buildings, to making circular building standard practice.
Areas such as Drottninghög in Helsingborg are in need of revitalization and development. Demolishing and building new buildings entails creating a greater environmental impact, more waste, and an increased use of resources in comparison with maintaining and renovating buildings. That is why reusing materials such as concrete could be an important method with which a reduction of the negative environmental effects could be achieved.
The Swedish contributors, KTH and Helsingborgshem, are presenting their first results and practical examples of how building materials can be reused.
For at least half a century, concrete has been the world’s most used building material and, at the same time, accounts for the majority of both building materials and demolition waste and is carbon dioxide demanding. Despite its great potential, a very small part of the concrete is recycled. ”We want to change that in the ReCreate project!”, says Erik Stenberg – architect and senior architecture lecturer at the KTH School of Architecture and the built environment (ABE) in Stockholm.
ReCreate is an international EU-funded project that is led by KTH in Sweden, which, together with Helsingborgshem and Strängbetong, uses recycled concrete elements from, among other things, demolished houses in the residential area of Drottninghög in Helsingborg. The recycled concrete is then used as a building material in the Swedish project’s pilot which will be part of the city fair H22 City Expo in Helsingborg this summer.
”By reusing concrete elements and developing circular construction, it may be possible to reduce climate impact and waste volumes in the future. The project develops and examines the changes needed in the entire construction process when concrete is recycled; from demolition to the design of a new building and its dismantling, to see how it is possible to use all concrete elements or just parts of them in new buildings.” Erik Stenberg explains.
In January 2020, Helsingborgshem began demolishing three multi-family houses on Grönkullagatan on Drottninghög to make room for the new City Quarter. In connection with the demolition, concrete elements were dismantled and preserved, which have now been analyzed and recycled within the ReCreate project.
”We want to reduce both our climate impact and our waste volumes. Therefore, it feels important that we develop circular construction so that in the event of future demolition, we will hopefully be able to reuse concrete elements on a larger scale. During H22, we want to spread the knowledge and hope to inspire the real estate and construction industry to continue development in recycling”, says Christine Delander Eksten, project manager at Helsingborgshem.
As part of the H22 City Expo at Drottninghög, several proposals for the recycling of concrete elements will be presented.
”There will of course be a focus on how new buildings can be created with old concrete elements. We will present and show how the exhibition building itself has been built and we will have 3D-printed models of cutting-edge projects from our ReCreate colleagues in Finland, Germany, and the Netherlands on site. The next generation of architects from KTH have made student projects based on the recycled concrete elements from Drottninghög and its dimensions and conditions”, says Erik Stenberg.
Visit ReCreate and the H22 City Expo between May 30 and July 3. Welcome to Drottninghög!
The international City Expo at Drottninghög will take place from May 30 – to July 3, 2022, where the city of Helsingborg will be inviting the world to take part in the city’s sustainable and innovative social solutions. Helsingborgshem will be developing the area, along with the residents, the city of Helsingborg, and various other partners. The innovative and dialogue-based approach has generated international interest and during the H22 City Expo, you will be able to see the development on site. There will be a folk festival, food, experiences, lectures, music, and exhibitions. Welcome to Drottninghög and H22 City Expo this summer!
More on the ReCreate pilot project
ReCreate’s Swedish pilot project during the city fair H22 City Expo will be a small building that is only a stone’s throw from the center of Drottninghög. The pilot project consists of recycled concrete elements and other concrete parts and is built on a concrete slab where a preschool previously stood. The concrete comes from demolished houses in Drottninghög and other demolition properties in Helsingborg. Extruded concrete will also include the concrete parts that have been left over in their production and windows and doors that will be recycled from the preschool, while the amount of newly produced material in the pavilion will be limited. After H22, the pavilion will be dismantled as it was designed to be disassembled easily. The project is currently working on finding recipients who can reuse the different parts after H22 and is co-financed by EU Horizon 2020.
On the 7th of April, the ReCreate team of the AG Constructional Recycling of the BTU Cottbus met with the project partners at the location of the potential donor building Otto-Nuschke-Str. 9-14 (see photo 1) in Hohenmölsen for the 3rd German country cluster meeting, where Mr. Gottschling (Ecosoil GmbH) and the architect Mr. Dreetz were present as project partners.
Additionally, the mayor of the small-town Mr. Haugk and the chairman of WoBau Hohenmölsen GmbH (owner of the potential donor building) Mr. Luckanus also attended the meeting. After a discussion in the town hall on the possible realization of a (re)construction project with the used concrete elements and on the organization of the deconstruction itself, a possible building site (see photo 2) and the deconstruction object (donor building) in Otto-Nuschke-Str. were visited. On April 19, the gutting of the upper two floors of the residential building will begin and the scaffolding will be erected. From May 2 onwards, the partial deconstruction will be carried out by the company Ecosoil GmbH.
The BTU research team has begun to examine the condition of selected concrete elements intended for reuse in the installed position. In addition to geometric construction surveys, concrete compressive strength measurements were carried out using rebound hammers (see photo 3). The purpose of this is to evaluate the structural condition of the concrete elements, which are about 40 years old, so they’ll be able to make a statement on their reuse within the scope of the suitability test. The technical measurement investigations will be continued in April along with the involvement of students and finally, the concrete elements suitable for reuse will be marked.
Tampere University researchers from WP 7 in Finland visited KTH and the Swedish country cluster in Stockholm in October 2021
Two researchers, Linnea Harala and Lauri Alkki, from Tampere University Work Package 7 in Finland visited KTH and the Swedish country cluster in Stockholm in October 2021. The research of Work Package 7 focuses on the business aspects within ReCreate and the first research deliverable focuses on mapping the local ecosystems of concrete element reuse. The examination of these ecosystems was initiated in summer 2021 within the Finnish Country Cluster by research interviews and ethnographic follow-up. After we had gained a basic overview of the actors, their linkages and ecosystem structures within the Finnish country cluster, we expanded our ecosystem research activities to the Swedish country cluster.
During the research visit to Stockholm, Linnea and Lauri were warmly welcomed to KTH by the Swedish country cluster. This first research visit included formal and informal activities facilitating to get to know each other during meetings, campus tours and delicious lunches. The main research activities included research interviews with the key ecosystem actors and ethnographic follow-up on a reference project site visit and during the Swedish country cluster meeting. However, in addition to these research activities, networking and exchanging knowledge between the country clusters was also of great importance for the collaboration between the Finnish and Swedish country clusters.
ReCreate’s first cross-country cluster research visit exceeded our expectations and laid the groundwork for international future research collaboration within ReCreate. International collaboration was soon initiated as at the beginning of 2022 researchers from the Finnish country cluster started a joint research publication project together with researchers from the Swedish country cluster. This article aims to create an understanding of the concrete element reuse ecosystems in Finland and Sweden. All in all, this research visit was a great way to initiate cross-country cluster collaboration within ReCreate, exchange ideas and knowledge and ultimately improve ReCreate’s influence to maximize impact.
ReCreate project and Country cluster and work package 1 leader Erik Stenberg from KTH Royal Institute of Technology, are featured in The magazine Rum’s editorial staffs’ annual list of the 100 𝐦𝐨𝐬𝐭 𝐩𝐨𝐰𝐞𝐫𝐟𝐮𝐥 𝐢𝐧 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐃𝐞𝐬𝐢𝐠𝐧 𝐢𝐧 𝐒𝐰𝐞𝐝𝐞𝐧! 🎉
Rum is a magazine about architecture, interior design, and design aimed at professional architects and designers or people with a special interest in these areas.
The first months within the ReCreate project brought forward a vital step in moving the project forward with the completion of its first Milestone within the Work Package 8 (Policy support and social acceptability).
The Milestone, developed by Tampere University, with Paul Jonker-Hoffrén as the main author, is the Fieldwork protocol, which ensures consistency and compatibility in data collection. The Fieldwork protocol focuses on the study of work in the circular economy, and its primary goal is to ensure consistency and compatibility in data gathering for Task 8.2.
Work package 8 includes fieldwork at the (de)construction sites as well as interviews with policymakers and other actors, with a specific focus on work and work processes. This fieldwork protocol is centred on creating a set of research steps that is useful for both observational fieldwork and interviews.
The ReCreate project has at its core four pilot projects, in which concrete elements are reused. The pilot projects are constructed at different phases of the project, due to the availability of the elements and the flow of the policy processes related to construction projects. The pilots are in Germany, the Netherlands, Finland and Sweden. The four countries are different in terms of policy environments and pilot projects. However different these pilot projects may be on the surface, on a different level employees and other workers face the same elementary problem of work: how to translate a given task into concrete actions. Experience and education form the basis for the practice of work.
The fieldwork protocol includes sections on ethnographic and interview methods specifically adapted to the research setting in ReCreate. Construction sites are potentially hazardous, therefore data collection should take into account the role of the researcher in maintaining workplace safety. Furthermore, the construction site has a specific rhythm and space, which the researcher should understand and respect.
These border conditions add to the understanding of work in the circular economy. Performing ethically sound data collection in the construction sector includes not only the regular privacy issues but also specifically consideration of work safety issues.