Posts tagged with "thin shell structures":

Ultrathin concrete roof to cap a net-positive energy rooftop apartment

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A full-scale prototype of the design was the culmination of a four-year research project by ETH Zürich, and now the thin-shell integrated system's concrete roof is under construction. The razor-thin assembly, built over the course of six months, tapers to an impressive one-inch thickness at the perimeter, averaging two inches thick across its more than 1,700 square feet of surface area. The ongoing project, sponsored by ETH Zürich, NCCR Digital Fabrication, and Holcim Schweiz, will lead to the completion of a rooftop apartment unit called HiLo, which will offer live-work space for guest faculty of Empa, the Swiss Federal Laboratories for Materials Science and Technology.  
  • Facade Manufacturer Jakob (cables); Bruno Lehmann (rods and cable-net components); Blumer Lehmann (timber); Dafotech (steel supports + plates); Bieri (fabric cutting + sewing)
  • Architects supermanoeuvre; Bollinger+Grohmann
  • Facade Installer Marti (general contractor); Bürgin Creations (concrete); Holcim Schweiz (concrete development); Doka (scaffolding)
  • Facade Consultants ETH Zürich (Block Research Group, Mathematical and Physical Geodesy, Automatic Control Laboratory)
  • Location Zürich & Dübendorf, Switzerland
  • Date of Completion 2017-18
  • System thin shell concrete with integrated systems
  • Products custom assembly of concrete, steel cable net, polymer textile formwork, heating and cooling coils, insulation, and thin-film photovoltaic cells
The rooftop structure rises about 24 feet high, encompassing 1,300 square feet. Innovations in thin-shell building techniques were explored by the Block Research Group, led by Professor Block and senior researcher Dr. Tom Van Mele, together with the architecture office supermanoeuvre. The team purposefully avoided wasteful non-reusable formwork, opting instead to develop a net of steel cables stretched into a reusable scaffolding structure. The cable net supported a polymer textile that forms the shell surface. According to ETH Zurich press release, “this not only enabled the researchers to save a great deal on material for construction, they were also able to provide a solution to efficiently realise completely new kinds of design.” The construction technique leaves the interior floor area below the roof relatively unobstructed, allowing interior construction work to proceed concurrently. Altogether, this method is expected to condense construction to eight to ten weeks. Block Research Group and NCCR Digital Fabrication were able to digitally model dynamic forces wet concrete applies to the lightweight cable net and textile formwork, so that the overall geometry and structuring of the surface can be calibrated to produce an accurate result. This level of optimization is perhaps most evident in the capacity of the reusable formwork system to hold around 25 times its own weight (20 tons of wet concrete will eventually load onto the formwork).
Experts from Bürgin Creations and Marti sprayed the concrete using a method developed specifically for this purpose, ensuring that the textile could withstand the pressure at all times. Together with Holcim Schweiz, the scientists determined the correct concrete mix, which had to be fluid enough to be sprayed and vibrated yet viscous enough to not flow off the fabric shuttering, even in the vertical spots. The innovative concrete structure offers more than a new method for constructing concrete shell structures: it’s aim is to be an intelligent, lightweight energy-producing system. This is achieved by careful assembly of multiple layers of building systems. Two layers of concrete sandwich together insulation, heating and cooling coils, while thin-film photovoltaic cells wrap the exterior surface. The residential unit, enclosed by this roof system, and an adaptive solar-shaded facade, is expected to generate more energy than it consumes.  “We’ve shown that it’s possible to build an exciting thin concrete shell structure using a lightweight, flexible formwork, thus demonstrating that complex concrete structures can be formed without wasting large amounts of material for their construction” said Block in a press release. Because we developed the system and built the prototype step by step with our partners from industry, we now know that our approach will work at the NEST construction site.” You can view progress at the Dübendorf, Switzerland construction site via live webcam, accessed here.

Interactive Thermoplastic Pavilion by B+U

A thin shell pavilion with an audio feedback program invites engagement.

Apertures, the amorphous pavilion designed and fabricated by Baumgartner+Uriu (B+U) with students from SCI-Arc, challenges two of architecture’s defining dualities: the distinction between wall and window, and the division between exterior and interior. “Conceptually, we were looking at objects that are multi-directional and have apertures as their main theme,” said partner Herwig Baumgartner. “That was one aspect of it; the other was the barriers between inside and outside and how we can dissolve these. We’re interested in architecture that’s responsive through either movement or sound.” As visitors pass through or otherwise engage with the 16-foot-tall, 1/8-inch-thick structure’s many rounded openings, attached heat sensors trigger sounds based on human bio-rhythms, creating a feedback loop that encourages active exploration of the space. In addition to the themes of apertures and inside versus outside, B+U were interested in investigating the technology of thin shell structures. “How can you build something that’s over ten feet tall and very thin, and what’s the minimal material you can get away with?” asked Baumgartner. The architects used digital modeling software including Maya to determine the pavilion’s form, then constructed a series of mockups in different materials. “We’d be working with consultants, or we’d ask fabricators: how would they build this?” recalled partner Scott Uriu. “We were thrown quite a few interesting ideas. A lot of them wouldn’t quite pan out, but we were always working back and forth between digital and analog design.” The designers originally tried building Apertures out of acoustic foam. “It was interesting for us because it creates an absorptive environment, but it was very weak,” said Baumgartner. They considered supporting it with an egg-crate structure. “But in the end we said, ‘Let’s get rid of the structure and make the surface the structure,’” he explained. They landed on heat-formed plastic, a thin material that becomes self-supporting when molded into certain shapes. “We did a mockup and we really liked it,” said Baumgartner. “It’s glossy and shiny on the outside, but the inside was matte. It has a very different interior and exterior.” Matt Melnyck, a principal at Nous Engineering, worked closely with B+U to insure the pavilion’s stability.
  • Fabricator B+U with SCI-Arc students
  • Designers B+U
  • Location Los Angeles
  • Date of Completion 2014
  • Material thermoplastic polymer resin, aluminum rivets
  • Process Maya, modeling, CNC milling, heat forming, bolting, lifting
With 35 students from SCI-Arc, B+U CNC-milled polyurethane foam molds for the pavilion’s 233 panels. At Warner Bros. Staff Shop, they poured the hot plastic resin over the molds, then cut out and painted the components. Reveals and guides milled into the molds indicate attachment points; the panels are joined with aluminum rivets. On site at SCI-Arc, the design team assembled the panels into nine sections of 30-40 panels each before lifting them into place. Designed for easy assembly and disassembly, the structure “breaks down into 233 panels and nests well,” said Uriu. Media artist Hannes Köcher developed Apertures’ audio program based on B+U’s concept. “If you stick your head through the apertures or you walk through them, the majority of them have sensors. Different sensors trigger different sounds—we basically made a thermal map of the object,” said Baumgartner. “When you’re in the space and especially when there’s multiple people in the space, it heats up. The sound starts building up over time, almost like a polyphony thing.” Because the audio is delivered through transducer speakers, visitors feel as well as hear the rhythms. During its spring showing at SCI-Arc, the result was exactly as B+U had hoped, Baumgartner reflected. “People started interacting with it, entering into a sort of feedback with the sounds.”