Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting
The construction industry is a slow adopter of new technologies and materials. However, interdisciplinary research efforts in digital fabrication methods with concrete aim to make a real impact on the way we build by showing faster production, higher quality and enlarged freedom of design. In this p...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-05-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/13/9/2084 |
| _version_ | 1797569154410086400 |
|---|---|
| author | Anna Szabo Lex Reiter Ena Lloret-Fritschi Fabio Gramazio Matthias Kohler Robert J. Flatt |
| author_facet | Anna Szabo Lex Reiter Ena Lloret-Fritschi Fabio Gramazio Matthias Kohler Robert J. Flatt |
| author_sort | Anna Szabo |
| collection | DOAJ |
| description | The construction industry is a slow adopter of new technologies and materials. However, interdisciplinary research efforts in digital fabrication methods with concrete aim to make a real impact on the way we build by showing faster production, higher quality and enlarged freedom of design. In this paper, the potential and constraints of a specific digital slip-forming process, smart dynamic casting (SDC), are investigated with a material-focused approach in the complex task of producing thin folded structures. Firstly, the workability and the strength evolution of different material compositions are studied to achieve the constant processing rate for SDC. Secondly, friction between the formwork walls and the concrete, a key aspect in slip-casting, is studied with a simplified experimental setup to identify if any of these mixes would provide an advantage for processing. Finally, a theoretical framework is constructed to link the material properties, the process conditions and the designed geometry. This framework introduces the ‘SDC number’ as a simplified approach to formulate the process window, the suitable conditions for slip-forming. The experimental results prove the assumption of the model that friction is proportional to yield stress for all base compositions and acceleration methods regardless of the filling history. The results are evaluated in the context of the narrow process window of thin folded structures as well as the wider process window of columns. The necessity of consistent strength evolution is underlined for narrow windows. Further, friction is shown to be the highest initially, thus with both narrow and wide process windows, after a successful start-up the continuation of slipping is less prone to failure. The proposed theoretical model could provide material and geometry-specific slipping strategy for start time and slipping rate during production. |
| first_indexed | 2024-03-10T20:06:52Z |
| format | Article |
| id | doaj.art-d4fd3ede4aec4b189d7327f2b43a58cc |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T20:06:52Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-d4fd3ede4aec4b189d7327f2b43a58cc2023-11-19T23:13:29ZengMDPI AGMaterials1996-19442020-05-01139208410.3390/ma13092084Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic CastingAnna Szabo0Lex Reiter1Ena Lloret-Fritschi2Fabio Gramazio3Matthias Kohler4Robert J. Flatt5Institute of Technology in Architecture, ETH Zurich, Stefano-Franscini-Platz 1, 8093 Zürich, SwitzerlandInstitute for Building Materials, ETH Zurich, Stefano-Franscini-Platz 3, 8093 Zürich, SwitzerlandInstitute of Technology in Architecture, ETH Zurich, Stefano-Franscini-Platz 1, 8093 Zürich, SwitzerlandInstitute of Technology in Architecture, ETH Zurich, Stefano-Franscini-Platz 1, 8093 Zürich, SwitzerlandInstitute of Technology in Architecture, ETH Zurich, Stefano-Franscini-Platz 1, 8093 Zürich, SwitzerlandInstitute for Building Materials, ETH Zurich, Stefano-Franscini-Platz 3, 8093 Zürich, SwitzerlandThe construction industry is a slow adopter of new technologies and materials. However, interdisciplinary research efforts in digital fabrication methods with concrete aim to make a real impact on the way we build by showing faster production, higher quality and enlarged freedom of design. In this paper, the potential and constraints of a specific digital slip-forming process, smart dynamic casting (SDC), are investigated with a material-focused approach in the complex task of producing thin folded structures. Firstly, the workability and the strength evolution of different material compositions are studied to achieve the constant processing rate for SDC. Secondly, friction between the formwork walls and the concrete, a key aspect in slip-casting, is studied with a simplified experimental setup to identify if any of these mixes would provide an advantage for processing. Finally, a theoretical framework is constructed to link the material properties, the process conditions and the designed geometry. This framework introduces the ‘SDC number’ as a simplified approach to formulate the process window, the suitable conditions for slip-forming. The experimental results prove the assumption of the model that friction is proportional to yield stress for all base compositions and acceleration methods regardless of the filling history. The results are evaluated in the context of the narrow process window of thin folded structures as well as the wider process window of columns. The necessity of consistent strength evolution is underlined for narrow windows. Further, friction is shown to be the highest initially, thus with both narrow and wide process windows, after a successful start-up the continuation of slipping is less prone to failure. The proposed theoretical model could provide material and geometry-specific slipping strategy for start time and slipping rate during production.https://www.mdpi.com/1996-1944/13/9/2084smart dynamic castingset on demandacceleratorprocess windowSDC number |
| spellingShingle | Anna Szabo Lex Reiter Ena Lloret-Fritschi Fabio Gramazio Matthias Kohler Robert J. Flatt Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting Materials smart dynamic casting set on demand accelerator process window SDC number |
| title | Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting |
| title_full | Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting |
| title_fullStr | Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting |
| title_full_unstemmed | Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting |
| title_short | Mastering Yield Stress Evolution and Formwork Friction for Smart Dynamic Casting |
| title_sort | mastering yield stress evolution and formwork friction for smart dynamic casting |
| topic | smart dynamic casting set on demand accelerator process window SDC number |
| url | https://www.mdpi.com/1996-1944/13/9/2084 |
| work_keys_str_mv | AT annaszabo masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting AT lexreiter masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting AT enalloretfritschi masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting AT fabiogramazio masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting AT matthiaskohler masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting AT robertjflatt masteringyieldstressevolutionandformworkfrictionforsmartdynamiccasting |