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| fabformwiki:research:research_efforts [2023/10/11 18:51] – [International Research] rpschmitz | fabformwiki:research:research_efforts [2023/10/19 15:00] (current) – [Research Papers] rpschmitz |
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| <fs medium>The shape a wall panel could take was first explored using a plaster model with various interior support and perimeter boundary conditions (Figures 1-2). The cloth fabric, when draped over interior supports and secured at the perimeter, deforms as gravity forms the shape of the panel with the fluid plaster as shown in the completed plaster casts (Figure 3). Once a satisfactory design has been obtained, a full scale cast with concrete can be made.</fs> | <fs medium>The shape a wall panel could take was first explored using a plaster model with various interior support and perimeter boundary conditions (Figures 1-2). The cloth fabric, when draped over interior supports and secured at the perimeter, deforms as gravity forms the shape of the panel with the fluid plaster as shown in the completed plaster casts (Figure 3). Once a satisfactory design has been obtained, a full-scale cast with concrete can be made.</fs> |
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| <fs medium>The casting of a full scale panel using concrete requires finding a fabric capable of supporting the weight of the wet concrete. For this purpose, a geotextile fabric made of woven polypropylene fibers was utilized. Assorted interior supports were added to the formwork (Figure 4) and the flexible fabric material was pre tensioned at the perimeter (Figure 5). Depending upon the configuration of these interior support conditions, three dimensional funicular tension curves are produced in the fabric as it deformed under the weight of the wet concrete (Figure 6). Reinforcement added to the panel only served to hold it together and was not designed for any particular loading condition for the completed panel (Figures 7 and 8) Figure 9 shows the formwork used for the completed wall panel shown in Figure 10. Alternatively a completed wall panel may also serve as a form. The glass fiber reinforced concrete (GFRC) wall panel shown in Figure 11 was cast on the finished surface of the panel Shown in Figure 10.</fs> | <fs medium>The casting of a full-scale panel using concrete requires finding a fabric capable of supporting the weight of the wet concrete. For this purpose, a geotextile fabric made of woven polypropylene fibers was utilized. Assorted interior supports were added to the formwork (Figure 4) and the flexible fabric material was pre tensioned at the perimeter (Figure 5). Depending upon the configuration of these interior support conditions, three-dimensional funicular tension curves are produced in the fabric as it deformed under the weight of the wet concrete (Figure 6). Reinforcement added to the panel only served to hold it together and was not designed for any particular loading condition for the completed panel (Figures 7 and 8) Figure 9 shows the formwork used for the completed wall panel shown in Figure 10. Alternatively a completed wall panel may also serve as a form. The glass fiber reinforced concrete (GFRC) wall panel shown in Figure 11 was cast on the finished surface of the panel Shown in Figure 10.</fs> |
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| <fs medium>We believe however, until new fabrics are developed the benefits of using geotextiles far outweighs any disadvantages.</fs>\\ | <fs medium>We believe however, until new fabrics are developed the benefits of using geotextiles far outweighs any disadvantages.</fs>\\ |
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| ===== Engineering Complex Forms ===== | ===== Engineering Complex Forms ===== |
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| <fs large>See [[fabformwiki:research:usa:usa_schmitz|USA_Schmitz]] for current research efforts.</fs> | <fs large>See [[fabformwiki:research:usa:usa_schmitz|USA_Schmitz]] for current research efforts.</fs> |
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| ===== International Research ===== | ===== International Research ===== |
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| <fs medium>While the list of countries conducting research into the use of fabric as a formwork for architectural works continues to grow, the research at [[fabwiki:research:canada:canada_research|C.A.S.T.]] has been the most innovative and pioneering effort the author has seen to date. Their research centers on the development of new technologies for forming concrete structural members using fabric formworks. They seek to:</fs> | <fs medium>While the list of countries conducting research into the use of fabric as a formwork for architectural works continues to grow, the research at [[fabformwiki:research:canada:canada_research|C.A.S.T.]] has been the most innovative and pioneering effort the author has seen to date. Their research centers on the development of new technologies for forming concrete structural members using fabric formworks. They seek to:</fs> |
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| <fs medium>The engineering of these complex and exotic vault and thin-shell panel shapes will require an approach different than the form-finding approach described above for a horizontal fabric formed precast panel. Whereas Isler tested small scale models of his shell structures and then scaled them up to full size these vaults and thin-shell wall panels may already be at full-scale before they are put to use. Two approaches to the engineering analysis of these thin-shell panel shapes might be considered. One is a photographic method using a commercially available software program called PhotoModeler® Scanner [7]. This program imports images from a digital camera to create a dense point cloud and mesh data which can be exported to FEA software. Another method might be to use High Definition Laser Scanning which also creates a dense point cloud and mesh data which can be exported to FEA software. Both approaches will involve an iterative process where one would first image the basic member shape and then analyze it for the superimposed design loads. Results of the first analysis would show where weak points in the member occur. Further analysis would suggest to what degree the member needs to be built-up using additional textile reinforcement and concrete materials.</fs> | <fs medium>The engineering of these complex and exotic vault and thin-shell panel shapes will require an approach different than the form-finding approach described above for a horizontal fabric formed precast panel. Whereas Isler tested small scale models of his shell structures and then scaled them up to full size these vaults and thin-shell wall panels may already be at full-scale before they are put to use. Two approaches to the engineering analysis of these thin-shell panel shapes might be considered. One is a photographic method using a commercially available software program called PhotoModeler® Scanner [7]. This program imports images from a digital camera to create a dense point cloud and mesh data which can be exported to FEA software. Another method might be to use High Definition Laser Scanning which also creates a dense point cloud and mesh data which can be exported to FEA software. Both approaches will involve an iterative process where one would first image the basic member shape and then analyze it for the superimposed design loads. Results of the first analysis would show where weak points in the member occur. Further analysis would suggest to what degree the member needs to be built-up using additional textile reinforcement and concrete materials.</fs> |
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| ===== Conclusions and Further Research ===== | ===== Conclusions and Further Research ===== |
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| <fs medium>We hope this article has piqued your interest and left you inspired. Readers interested in additional information are encouraged to visit the websites listed under Further information especially, the [[http://www.umanitoba.ca/cast_building/|C.A.S.T.]] website at the University of Manitoba where numerous examples and literature on this topic may be found.</fs> | <fs medium>We hope this article has piqued your interest and left you inspired. Readers interested in additional information are encouraged to visit the websites listed under Further information especially, the [[http://www.umanitoba.ca/cast_building/|C.A.S.T.]] website at the University of Manitoba where numerous examples and literature on this topic may be found.</fs> |
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| ===== Research Papers ===== | ===== Research Papers ===== |
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| ===== References ===== | ===== References ===== |
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