Structural design, digital fabrication and construction of the cable-net and knitted formwork of the KnitCandela concrete shell
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Date
2021-06
Publication Type
Journal Article
ETH Bibliography
yes
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Abstract
This paper describes the structural design, digital fabrication and construction of KnitCandela, a free-form, concrete waffle shell with KnitCrete, a falsework-less formwork approach using a custom prefabricated knitted textile as multi-functional, structural shuttering layer and a form-found cable net as the main load-bearing formwork. The digitally designed and fabricated textile provided integrated features for inserting and guiding elements such as cables and inflatables that helped shape the sophisticated mould.
With a total weight of only 55 kg, the 50 m2 formwork was easy and compact to transport. On site, the formwork was tensioned into a timber and steel rig, the pockets were inflated, and then coated with a thin layer of custom-developed, fast-setting cement paste. This paste served as a first stiffening layer for the textile, minimising the formwork’s deformations during further concrete application. Fibre-reinforced concrete was manually applied onto the formwork to realise a 3 cm-thick shell with 4 cm-deep rib stiffeners.
The novel approach, for the first time applied at architectural scale in this project, enables the building of bespoke, doubly-curved geometries in concrete, with a fast construction time and minimal waste, while also reducing the cost and labour of manufacturing complex parts.
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Publication status
published
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Editor
Book title
Journal / series
Volume
31
Pages / Article No.
1287 - 1299
Publisher
Elsevier
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Flexible formwork; Weft-knitting; Stay-in-place formwork; Concrete waffle shell; KnitCrete; Digital fabrication
Organisational unit
03847 - Block, Philippe / Block, Philippe
03891 - Flatt, Robert J. / Flatt, Robert J.
02284 - NFS Digitale Fabrikation / NCCR Digital Fabrication
Notes
Funding
141853 - Digital Fabrication - Advanced Building Processes in Architecture (SNF)