Research has shown that using 3d knitted concrete shells in architecture can save on construction time and materials.
The prototype KnitCandela is the first application of knitted concrete on an architectural scale, and uses a 3d knitted shell. The prototype was exhibited in Mexico City, having been brought there inside two suitcases as normal checked baggage.
What is knitted concrete?
The prototype KnitCandela is a four metre tall curved knitted concrete shell. The structure is supported by a steel cable net. The knitted textile weighs only 25 kilograms and the cable net around 30 but they supported over 5 tonnes of concrete curves.
After the knitted textile had been transported to the museum in Mexico City, it was tensioned between a temporary boundary frame and sprayed with a specially formulated cement mixture. Although the initial layer was only a few millimetres thick, it was sufficient to create a rigid mould. Once the mould hardened, conventional fibre-reinforced concrete was applied.
According to ETH Zurich, the structure is an homage to Spanish-Mexican architect Felix Candela (1910-1997) and a collaboration with Zaha Hadid Architects Computation and Design Group (ZHCODE), and Architecture Extrapolated (R-Ex).
What is the advantage of 3d knitted shells for construction?
Mariana Popescu and Lex Reiter developed the technology as part of Switzerland’s National Centre of Competence in Research (NCCR) in Digital Fabrication research project.
Popescu commented: “Knitting offers a key advantage that we no longer need to create 3D shapes by assembling various parts. With the right knitting pattern, we can produce a flexible formwork for any and all kinds of shell structures, pockets and channels just by pressing a button.”
To a certain extent, the group is pioneering a new form of 3D printing. However, Phillipe Block, Professor of Architecture and Structure at ETH Zurich, adds: “it doesn’t require a completely new kind of machine. A conventional knitting machine will do just fine.”
The future for construction
According to ETH Zurich, Popescu’s research shows that using knitted concrete in architectural applications cuts down on material, labour and waste. Using a 3d knitted concrete shell also simplifies the construction process for complex shapes.