ReCon: Development of a resilient hook-and-loop-fastening-system for the adaptable assembly of building components in the building industry
Short Description
The global contribution of the construction industry to climate change becomes apparent on the basis of final energy consumption (approx. 34%), energy-related CO2 emissions (approx. 37%) and resource consumption (approx. 31%). A consistent circular economy can help to reduce these key figures, especially resource consumption. Two essential core elements of circular construction are "deconstructability" and essential "information" about the elements used, their composition and properties. Accordingly, the Austrian circular economy strategy from 2022 requires buildings to be flexible in terms of use, modular construction, separability and reusability of components. As well as the recording of material data over the entire life cycle and its documentation in digital form to strengthen reuse, recycling and recovery practices.
The current construction industry is based on the joining methods of casting, welding, gluing, foaming and sealing, while there is no management of component data (installation date, material composition, position, dismantling instructions, etc.) with a system that would be necessary for the establishment of a circular economy. As a result, buildings are currently being created that cannot be integrated into a circular economy, or only partially, and then only at great expense.
To solve these problems, this project proposes the establishment of a "resilient" hook and loop connection in building construction, between short-lived and long-lived and subsequently materially heterogeneous components. This connection offers damage-free dismantling as well as technical and spatial flexibility on a physical level, and continuous component data management on a virtual or digital level through the integration of current storage technologies. In this context, the aim of the project is to develop a concept for the hook-and-loop connection system (depending on the application situation) and to verify its applicability at component level. For this purpose, literature research, concept development and the experimental investigation of individual system components were carried out methodically. In each case at the construction, paper technology, electrical engineering and digital levels.
As a result, two application situations ("floor slab in concrete construction" and "floor slab in timber construction") were defined, the potential of the hook-and-loop connection in these situations was determined and the constructional requirements (service life, load transfer) were analyzed. Furthermore, concepts for a hook and loop connection system were developed. To this end, literature research, concept development and the experimental investigation of individual system components were carried out using laboratory tests. In each case on a structural, paper technology, electrotechnical and digital level.
During the tests with industrial hook and loop products, a ductile load-bearing behavior of the hook and loop connection was determined. The large deformations that hook and loop can absorb are ideal for structural applications, as this ensures that failure is announced and load redistribution is possible in many applications. It was also found that, depending on the hook and loop product, both the orientation of the two hook and loop components in relation to each other and the temperature (can) have an influence on the adhesive tensile strength. It was also confirmed that (larger) eccentricities of the load application lead to a reduction in the adhesive tensile strength (in relation to the entire hook and loop surface) due to the one-sided load.
As part of manufacturing tests, concrete and wooden hook and loop components with round and square mushroom head elements as well as with T-shaped or V-shaped grooves were produced. Plastic hook and loop components, which were produced using 3D printing in different scales and geometries (X-mushroom heads and O-mushroom heads), form the counterpart. A hook and loop paper system was developed and produced that includes folded or curved mushroom heads, as well as a counterpart consisting of slots that are narrower than the thickness of the mushroom heads. All of these hook and loop systems developed in the project have adhesive tensile strengths that are comparable with commercially available hook and loop products.
As a building component data system, a building structure was defined on a digital level and provided with potentially required metadata, as well as translated into a digital dashboard and an electronic level. In addition, the system was applied using selected user scenarios (planning with reuse components, maintenance and repair). At the electronic level, a system was developed in which RFID chips and QR codes are located on or on the side of the architecture, in predefined elements or in rooms.
In follow-up projects, the behavior of the industrial hook-and-loop connection under alternating climatic stresses and the influences on the adhesive tensile strength are to be investigated further. The processes used in the project to produce hook and loop components from raw building materials were used to test feasibility and have not yet been optimized in terms of process, technology or ecological aspects. This needs to be addressed in follow-up projects. There is also a need for research into the further development and specification of the component data system in the context of different users and the integration of digital component information into existing planning environments. As well as the integration of unique identifiers (RFID chips, QR codes) and basic data (long-term archiving) into the building construction.
Project Partners
Project management
Graz University of Technology, Institute of Architecture Technology
Project or cooperation partners
- Graz University of Technology, Laboratory for Structural Engineering
- Graz University of Technology, Institute of Bioproducts and Paper Technology
- Axtesys GmbH, Graz
- NET-Automation GmbH, Zeltweg
Contact Address
Graz University of Technology
Institute of Architecture Technology
Rechbauerstr. 12/I
A-8010 Graz
Univ.-Prof. Dipl.-Ing. Architekt Roger Riewe (project manager)
Tel.: +43 (316) 873 6300
E-mail: riewe@tugraz.at
Web: www.iat.tugraz.at
Dipl.-Ing. Dr.techn. Matthias Raudaschl (deputy project manager)
Tel.: +43 (316) 873 6808
E-mail: matthias.raudaschl@tugraz.at
Dipl.-Ing. Toni Levak (University Assistant)
Tel.: +43 (316) 873 6307
E-mail: toni.levak@tugraz.at