ETH Zurich, working in collaboration with Zaha Hadid Architects Computation and Design Group (ZHCODE) and Architecture Extrapolated (R-Ex) have unveiled a 3D-knitted shell serving as the primary shaping element for curved concrete structures.
The “KnitCandela” prototype represents the first application of this technology at an architectural scale, a five-tonne concrete structure on display at the Museo Universitario Arte Contemporaneo in Mexico City.
Forming part of ZHA’s first exhibition in Latin America, KnitCandela “pays homage to the Spanish-Mexican architect and engineer Felix Candela” by reimagining his inventive concrete shell structures through an innovative KnitCrete formwork technology. With a knitting time of 36 hours, the cable-net and fabric formwork system allows for expressive, freeform concrete surfaces to be constructed without the needs for molds.
The knitted fabric for KnitCandela, developed at ETH Zurich, was transported from Mexico to Switzerland in two checked suitcases, totaling 350 kilometers of yarn weighing 25 kilograms. The pavilion’s thin, double-curved concrete shells hence weigh only 5 tonnes in total, despite a surface area of 50 square meters.
The pavilion was constructed using a double-layered 3D textile consisting of four long strips. The lower layer forms the ceiling, adopting a colorful pattern, while the upper layer contains “sleeves for the cables of the formwork system and pockets for simple balloons, which, after the entire structure is coated in concrete, become hollow spaces that help save on materials and on weight.”
The soft, colorful textile interior of KnitCandela’s shell and its hard, concrete exterior is visible from all viewing angles. The textile’s striped pattern expresses the knitting fabrication process and the radial symmetry of the shape. This patterning, along with the simultaneous visibility of the soft interior and the hard exterior of the shell enhances the visitor’s spatial experience and the curvatures of the KnitCandela’s form.
-Zaha Hadid Architects
News of the innovative pavilion follows news earlier this year that ETH Zurich has fabricated the world’s first full-scale architectural project using 3D sand printing. 2018 also saw the university use robots to construct a three-story timber-framed house.