Blog posts - Recreate

December 8, 2023

Ahmad Alnajjar, PhD student at KTH

ReCreate project is a forward-thinking initiative that explores the reuse of precast concrete elements from various angles. A key aspect of this project is evaluating the climate benefits from a life cycle perspective. Our recent work, particularly in the Swedish pilot construction, has shown promising results in reducing embodied carbon – a crucial step in sustainable and circular building practices. About 92% of embodied carbon was avoided at the building level which is largely attributed to the reuse of concrete elements, including precast concrete elements. This achievement aligns with previous research highlighting the benefits of reusing precast concrete and further emphasizes the reuse’s effectiveness in mitigating the environmental impact of construction. Unlike most previous studies, the embodied carbon evaluation of the Swedish ReCreate pilot project stands closer to real-world applicability. It is based on field experiments conducted by seasoned professionals in the building sector, adding practical validity and depth to our findings.

An important facet of our findings in the ReCreate project underscores a significant advantage in the reuse of whole precast concrete elements over traditional recycling methods. Through our comprehensive analysis, it has become evident that the embodied carbon savings achieved by reusing entire elements are considerably greater than those realized by merely crushing to recycled concrete aggregate and shredding the rebar to steel scrap. This distinction is crucial, as it highlights the substantial environmental benefits of reusing structures in their complete form. By opting for reuse over recycling, we not only retain the material’s inherent value but also significantly reduce the carbon footprint associated with the production of new building materials.

Our assessment has also brought to light interesting insights. Contrary to common concerns, we found for example that the transportation of reused elements does not significantly add to the project’s carbon footprint, as it is comparable to the transport distances of new building materials. We hope that this finding will encourage building industry actors to reconsider their material sourcing strategies, recognizing that incorporating reused elements can be both environmentally beneficial and logistically viable.

Currently, our team is focused on comprehensively understanding the future availability and demand for pre-used precast concrete elements. We are assessing both the timing of their availability and the quantities that can be effectively reused in new construction projects. By addressing these critical aspects, we aim to elucidate the role that reusing precast concrete elements can play in meeting Sweden’s and the EU’s ambitious climate goals.

Through the ReCreate project, we are exploring new avenues in construction, aiming to make a meaningful contribution to sustainable building practices. Our team is dedicated to not only implementing these innovative practices but also to rigorously documenting and analyzing our findings. Our research will soon be available in various scientific journals, providing a detailed and scholarly overview of our work and its implications for sustainable construction. Keep an eye on our progress as we delve further to uncover the potential and challenges of this innovative approach and look out for our publications to gain a deeper understanding of the impact and scope of our project.

by ReCreate project

November 13, 2023

Matias Rokio, Tampere University – 13 November 2023

My name is Matias Rokio, and for the year 2023, I’ve been doing research in ReCreate. My background is in industrial engineering and management, and I have been studying since 2017 at Tampere University. I graduated with an M.Sc in June 2023 and wrote my Master’s thesis on resilience in Finnish health care with an emphasis on information asymmetries. My minor in sustainable production steered me towards the areas of sustainability and circular economy, which I feel should receive a lot of attention in research in varied fields. Currently, I am in the process of applying for a doctoral position at Tampere University, which I will hopefully receive sometime during this year. In my personal life, along with my work as a researcher, I am a semi-professional drummer in a few different groups and doing all kinds of session work for different artists.

Currently, I am working at Tampere University in a CROPS research group, which collaborates with ReCreate’s WP7 through my research. According to WP7 objectives, the work package aims to accelerate the development of a scalable and profitable business model for reused precast concrete components in different environments. Especially within the construction industry, the circular economy has tremendous potential in driving a transition towards more sustainable practises, as concrete manufacturing alone generates around 4-8% of the world’s CO2 emissions.

My research article on ReCreate approaches the concrete element reuse from project management’s perspective, with an aim to unveil how applying circular economy principles in projects affects the inter-organisational collaboration and value creation in the project front-end. In my research, the front-end spans the planning phase of the Finnish country pilot, where the deconstruction of an office building in Tampere city centre and the subsequent phases to it were planned in detail. The purpose of the research is to enrich the discussion around sustainable project management and showcase a project where sustainability is promoted through circular economy practises. Also, the circular economy discussion, despite its trending and important nature, is currently still lacking in the project management context, which makes the research interesting for project management scholars.

In the research, we found out that when a construction project is based on the reuse principle, the front-end phase requires more actors to collaborate in the project planning and some actors are required to take on new tasks in the project. For example, a structural engineering company was an integral part of the deconstruction planning of the building, whereas, in a conventional demolition project, the demolition company does the planning by themselves. It is also evident that there are several new business opportunities for the actors involved that could build new services and marketplaces around the reusable concrete elements and reach new customers through collaboration in the project. Currently, several barriers to the wider adoption of concrete elements reuse still remain, as manufacturing new concrete elements is relatively cheap whilst detaching, and refurbishing the old elements is somewhat time-consuming, and a regulative incentive for adopting the reuse principle is lacking.

by ReCreate project

November 10, 2023

Viktoria Arnold, researcher at BTU Cottbus – Senftenberg, Germany

The assessment of the sustainability of buildings has been increasing rapidly in recent years. This is not only related to the international goals of the United Nations, which are set out in Agenda 2030[1] and include global ecological, economic and socio-cultural aspects in the building sector (SDG 11[2], 12[3] and 13[4]). It is also linked not only, but in large part, to the national goals of the United Nations, which each country has set for itself. Germany, for example, has set a goal of achieving greenhouse gas neutrality in its building stock by 2050[5]. Different countries have different requirement methods. Some countries have made it mandatory to submit a so-called Climate Declaration for future building during the approval phase and to comply with certain limits for greenhouse gas emissions, such as the Netherlands, Sweden and Finland. Other countries, such as Germany, subsidise climate-friendly construction and renovation measures. Some builder-owners are just interested in building sustainably and climate-friendly and want to know what design decisions, building products and materials have what impact on the environment. And what contribution the building as a whole makes to resource and climate protection during its entire life cycle. To find this out, many sustainability assessment systems for buildings are used, which have LCA (Life Cycle Assessment) as one of the most important criteria. The basis for LCA is the EPDs (Environmental Product Declarations) based on ISO 14025 and EN 15804 for the different building products and materials. The more building products and materials have an EPD, the more accurate the calculation of the environmental impact of a building. This will greatly assist the builder-owner when deciding on certain construction and architectural solutions, and what contribution the building as a whole makes to resource and climate protection throughout its complete life cycle.

I am doing my doctorate at BTU on sustainability assessment of single-family houses. For such buildings, which are nowadays a luxury from a climatic point of view, such an assessment is particularly important.

In the ReCreate project, our German Cluster is particularly responsible for work package 6 “Energy and Climate”, which aims to evaluate the environmental and economic impacts (LCA and LCC (Life Cycle Costing)) of the reuse of precast concrete elements. Our major objective is to produce one or more EPDs for the precast concrete elements (ceiling, exterior and interior wall) suitable for reuse. This will enable LCA for new buildings with the reused elements and distinguish such resource and climate-friendly projects from others. Several previous research projects led by Prof. Angelika Mettke[6] have shown that the reuse of concrete building elements can significantly reduce the carbon footprint and energy consumption in the product phase by up to 93-98% compared to new production[7].

We notice again and again in our research that reuse can only be possible if the parts are still considered in the installed condition and the careful disassembly is carried out by an experienced company in the best case. Recently, the new DIN SPEC 91484[8] has been published, which is the basis for evaluating the high-quality connection potential for building products before demolition and renovation works where Prof. Mettke has been involved. Another prerequisite for successful reuse is that the building documents are available and, if possible, up to date. This is rarely the case with existing industrially constructed buildings that are up for deconstruction. That is why today’s initiative on the building resource passport is very important, where all building materials and products used, as well as their quality and recyclability, are recorded and kept up to date. It is also important to look now at what can be used to build more sustainable buildings so that the new building can be reused later at the end of its life cycle.

I am asking all these research questions in my doctoral thesis because it is still not so far that one comes to the idea of building a single-family house from used precast concrete elements.

[1] Sustainable Development Goals

[2] SDG 11 Make cities inclusive, safe, resilient and sustainable

[3] SDG 12 Ensure sustainable consumption and production patterns

[4] SDG 13 Take urgent action to combat climate change and its impacts

[5] Deutsche Nachhaltigkeitsstrategie Weiterentwicklung 2021, p. 103

[6] Structural Recycling Unit, Faculty 2 of Environment and Natural Sciences, BTU Cottbus – Senftenberg

[7] Mettke, A. (2010). Material- und Produktrecycling – am Beispiel von Plattenbauten. Zusammenfassende Arbeit von 66 eigenen Veröffentlichungen, Cottbus, Techn. Univ., Habil.-Schr. p. 235–243

[8] DIN SPEC 91484:2023-09 “Procedures for recording building products as a basis for evaluations of connection use potential prior to demolition and renovation work.”

by ReCreate project

September 27, 2023

Arlind Dervishaj, architect and doctoral researcher at KTH Royal Institute of Technology

The use of digital tools for the design of buildings has become a common practice for architects and engineers alike, commonly referred under the umbrella term digital design. The range of digital tools at our disposal and their utilization has been growing, with reference to Building Information Modelling (BIM), environmental design tools, computational design plugins, and optimization algorithms. Additionally, 3D printing, robotic fabrication, virtual reality, and Artificial Intelligence (AI) are becoming more commonplace not only in research environments but also with practical applications within the architecture and engineering fields. Despite these advancements that have made it easier to design and assess the sustainability of projects, buildings remain a major contributor to climate change, responsible for 37% of global carbon emissions, half of all extracted raw materials, and waste generation due to construction and demolition activities. In light of these challenges, the circular economy concept presents a promising solution, with digital technologies playing a crucial role as enablers. The importance of reevaluating the relationship between design and the digital became the focus of the 41^st eCAADe (Education and Research in Computer-Aided Architectural Design in Europe) conference hosted at TU Graz under the theme Digital Design Reconsidered.

At eCAADe 2023, I presented a refereed paper, with co-authors Arianna Fonsati, José Hernández Vargas, and prof. Kjartan Gudmundsson [1]. The paper is titled Modelling Precast Concrete for a Circular Economy in the Built Environment with subtitle Level of Information Need guidelines for digital design and collaboration. This was also the first presentation in the eCAADe session on BIM & Sustainability. I kicked off my presentation by captivating the audience with striking examples of AI-generated buildings crafted from reclaimed concrete elements, setting the stage for an important question to follow.

Can we design buildings with reused elements simply with a text prompt and AI or is there more to consider?

Before the design process, the practice of reuse involves a series of essential steps, which encompass, among other things, the identification of suitable buildings and components for reuse, the process of deconstruction, the management of storage, and the implementation of quality assurance measures. Reliable and up-to-date information is crucial in supporting designers and stakeholders in making decisions for circular construction. Various data capture methods for buildings exist to facilitate their identification and potential reuse. These methods encompass technologies such as laser scanning, photogrammetry, scan-to-BIM workflows, and machine learning algorithms. Examples of the latter include identifying materials and components at urban and building scales, and some even automate the creation of 3D models from point clouds.

Nevertheless, a substantial gap remains within the literature with relevance for practice concerning the specifics of required data and the process of sharing and requesting information to enable reuse and collaboration of different parties. To address this challenge, we developed a set of digital reuse guidelines tailored specifically for precast concrete. These guidelines are based on the Level of Information Need (LOIN) standard EN 17412-1:2020 [2], and are informed by our experience in the ReCreate project, which includes construction pilots conducted in Sweden (Swedish pilot at the H22 City Expo) and in partner countries. Our study not only embraces the EN 17412 standard but also takes it a step further by extending its applicability for digital reuse in circular construction. These guidelines are designed to enhance the reliability of information across the reuse process and construction cycles. They introduce innovative concepts, such as the creation of digital templates that evolve into digital twins of reused precast elements. Furthermore, they can be used for specifying information requirements for reused as well as for newly produced elements. Additionally, as part of our comprehensive approach, we have included a comparison of the geometrical modelling aspects of LOIN in two widely used CAD and BIM software platforms, Rhino and Revit.

Currently, our ongoing research within the ReCreate project continues to explore and expand upon various aspects that can relate to the LOIN framework. As an example, another recent paper authored by me, José, and Kjartan was presented at the 2023 EC3 & 40^th CIB W78 conference in Crete, Greece [3]. This paper explores the timely theme of tracking and tracing building elements, where more background information can be found in the literature [4], [5]. We present a novel digital workflow for modelling various tracking tags in the BIM model such as QR codes, Radio Frequency Identification (RFID), and Bluetooth. Moreover, we present promising results from laboratory tests that, arguably for the first time, explore the utilization of Near Field Communication (NFC), which is a subset of RFID, and its integration with Bluetooth technology.

More facets on the topic of reuse are being investigated within ReCreate that will further demonstrate the applicability and potential of digital reuse in creating a circular built environment. Our research encompasses a wide spectrum of considerations, including data capture and sharing methods, material passports, destructive and non-destructive testing of concrete structures, and innovations in the design processes. These ongoing efforts aim to advance sustainability and circularity in the built environment through the integration of digital technologies.

References:

[1] A. Dervishaj, A. Fonsati, J. Hernández Vargas, and K. Gudmundsson, “Modelling Precast Concrete for a Circular Economy in the Built Environment,” in Digital Design Reconsidered – Proceedings of the 41st Conference on Education and Research in Computer Aided Architectural Design in Europe (eCAADe 2023), W. Dokonal, Hirschberg Urs, and G. Wurzer, Eds., Graz: eCAADe, TU Graz, Sep. 2023, pp. 177–186. doi: 10.52842/conf.ecaade.2023.2.177.

[2] European Committee for Standardization (CEN), “Building Information Modelling – Level of Information Need – Part 1: Concepts and principles (EN 17412-1:2020),” 2020 Accessed: May 18, 2022. [Online]. Available: https://www.sis.se/en/produkter/standardization/technical-drawings/construction-drawings/ss-en-17412-12020/

[3] A. Dervishaj, J. Hernández Vargas, and K. Gudmundsson, “Enabling reuse of prefabricated concrete components through multiple tracking technologies and digital twins,” in European Conference on Computing in Construction and the 40th International CIB W78 Conference, Heraklion: European Council on Computing in Construction, Jul. 2023, pp. 1–8. doi: 10.35490/EC3.2023.220.

[4] M. Jansen et al., “Current approaches to the digital product passport for a circular economy: an overview of projects and initiatives,” vol. 198, 2022, doi: 10.48506/OPUS-8042.

[5] European Commission, “Transition pathway for Construction.” Accessed: Mar. 17, 2023. [Online]. Available: https://ec.europa.eu/docsroom/documents/53854

by ReCreate project

September 14, 2023

Using object-oriented programming to bridge the gap between architecture and structural engineering in a circular design.

Fred Mudge, Eindhoven University of Technology – 14 September 2023

Over the past several decades, the construction industry has been responsible for large portions of annual global CO₂ emissions and overall material usage. To counteract this, the ReCreate project aims to establish a circular value chain for precast concrete buildings – a switch which could offer massive improvements to the industry’s sustainability by keeping materials in use for longer, thereby preserving the value contained in the existing building stock and reducing the need for new materials. This requires research and development across the entire reuse process, from deconstruction, transport and logistics, quality control, design and planning of new buildings up to reassembly in a new location and for a new purpose.

As a doctoral researcher at TU Eindhoven, my work focuses on the topic of design within the above context and aims to assist architects and engineers to design circular buildings, by developing a software application which provides functionality specifically for this task.

In a traditional building design workflow, the architect normally produces a design based on relatively few constraints. A structural engineer reviews the design and presents reinforcements to ensure that the structure is sufficiently robust and stable. After all designs have been finalized, construction can commence and (for precast systems) elements are manufactured that match the designs. The design process for reused elements is fundamentally different because the geometric and structural attributes of the elements are already fixed at the start of the design process. The challenge for a designer is therefore to select and arrange elements into a spatially effective building structure considering their respective geometries. Each addition or change to this arrangement affects the distribution of forces through the structure. The forces exerted on each element should therefore be calculated continuously and compared to its relevant structural capacities (axial force, bending moment etc.) to ensure no element is loaded past a safe limit.

The design application addresses both challenges mentioned above. It includes a feature for browsing through a library (database) of previously used building components that are available for reuse. A user can then select and import desired elements directly into a 3D building information modelling (BIM) environment and place them in a new design assembly. Furthermore, automatic structural load calculation methods using finite element methods (FEM) are built into the application and can be performed on-demand, to identify any elements exerted past their capacities. Lastly, environmental benefit is quantified and enhanced by automatic embodied carbon calculation, considering factors such as the distance of an element from the construction site and the amount of CO₂ required to get it into its new position.

Considering the novelty of reusing concrete building components, the first step to developing the application was to create a so-called “object model” for creating and storing digital representations of physical building elements. This requires a sound understanding of the parameters that describe all relevant aspects (geometric, structural etc.) of the various types of elements (beams, columns, wall panels, slabs etc.). These parameters, element types and how they interact and relate to each other also help define the database schema for storing element information (i.e., the element library). A trial database was created and populated with element data from a recently completed deconstruction project – Prinsenhof A in Arnhem, the Netherlands.

A user can browse through a library of elements, import and position them in a Revit model to make up a new building design.

Subsequently, the focus shifted to developing algorithms for automatically connecting elements within the model, based on their relative locations, and for calculating structural forces and moments within all elements, based on expected floor loadings and the anticipated “load paths” that eventually take all forces down to the building’s foundations. Lastly, a framework for calculating the environmental impact resulting from using new and reused precast concrete building components will be developed and added to the application, to ensure that an environmental benefit is achieved for each reuse design, compared to a design consisting of newly manufactured elements.

Currently, the design application is developed as an add-on for Autodesk Revit. New building designs are therefore in the form of a Revit (.rvt) model, which can be easily converted to a more universal format such as Industry Foundation Class (.ifc). The design application is currently still under development, with a “proof of concept” prototype planned for the end of 2023.

Newer Posts

Blog posts - Recreate - Page 2

ReCreating the building sector future toward net zero emission with precast concrete reuse

Circular Economy in Construction: Unveiling Sustainable Practices and Project Management Insights

EPD for the reused precast concrete elements to support the sustainability assessment of the buildings

Digital Reuse: Leveraging technology for a circular built environment in the age of AI

BIM software for designing with reused concrete building components

ReCreate is going to participate in the Tallinn Architecture Biennale 2024!

Exploring an informed design process in the reuse of structural concrete elements

Focusing on digital supply chain management and information sharing – interview with Kjartan Gudmundsson

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