An overview of methods to build full-scale
architectural complex (mostly double curved) surfaces and
structures.
1. Artisanal methods
a. There is a very long history to shaping building materials into
double curved structures. The fact that the 'natural' catenary form,
when reversed, forms an almost pure compression structure (with
hardly any bending or shear forces) made the resulting 'beehive'
shape much-favoured for the construction of simple stone or
adobe dwellings. No form work was needed for these construction;
some times a non-loadbearing form-guide system was employed to guide
the masons..
b. outlining the complex forms in a network of ribs was pratcticed
in Romanesque and Gothic arcitecture. These ribs were built on rigid
form work; in turn, the ribs supported the small double-curved
vaults, built without scaffolding, that made up the roof surface
structure.
2. Full-scaffolding method (still
built in artisanal manner)
a. Ruled surface forms (mainly hyperbolic paraboloids) were used
numerous times by the pioneering architect-engineer-builder Felix
Candela.
3. Prefabricated element system
a. In the Philips pavilion at the Brussled Expo 58 exhibition a
compex 3D volume made up by hyperbolic parabolois, is sub-divided in
small double curved reinforced thin concrete panles that are cast on
a sand bed mould. These elements are kept in place and post
tensioned by a double net of 7mm steel strands that are stretched
between rigi edge beams.
3. Computer aided design and construction
4. Modern, computer designed and robot manufactured complex
structures are generally made out of short straight structural
members, with a covering material (glass or metal panels) that, more
often than not, can be flat.
Examples: British Museum, London, roof and Patent office, Washington
D.C. roof, the Blob, Eindhoven Holland.Double curved glass panels
are used in Zaha hadids Nordpark inclined raiway stations in
Austria, and the Kunsthaus in Graz, Austria.
5. Modern computer designed 3D structures with a steel meber frame,
covered by double-curved gass panels that are cast in a
pre-fabrication shop.
Examples: Zaha Hadid Nord bahn in Salzburg Austria and hadi
Artisanal, scaffolding-free double-curved construction.
1. Compressive/composite materials
3D forms in Architecture, have, until about 20 years ago, been
created exclusively in an artisanal fashion.
Beehive domes (and similarly vaulted structures) have, since
time-immemorial been constructed, using mudbrick or stone. The
structual form follows (approximately) the funicular pattern, which
guarantees that the resulting structure is almost free of
bending forces; in addition, the form allows construction, layer by
layer with out the use of full-surface scaffolding.
Gramzio and Kohler's robot construction method essentially copy this
ancient system:
Double curved Gothic vaults as well as elaboratly
sculpted interiors during the Rocco era were always
hand-made, even though a reuse of hand-made molds would be
maximized.
Gothic double curved rib-guided
construction
gothic rib vault with double-curved infill
panels Gothic King's
College fan vault
Catalan vaults (again, this system could be
executed by Gramzio and Kohler's pick and place robot.)
The Catalan vault system is a unique system, using thin
ceramic tiles held together by unusually 'sticky' lime mortar, which
made it possible to build double curved shells of relatively large
spans by laminating 3 or more layers of these tiles,
cantilevering one layer out from the one before it, using no
structural form work, only lightweight guides to help the masons to
stay on course. This ancient technique was used to great effect by
the architect Antoni Gaudi, and was introduced into the United
States by the Guatovino family which used the system with great
success in major buildings like the Boston Public Library and Grand
Central Station in New York.
catalan vault construction
Guastovino system double-curved timbrel vualting system.
http://blog.makezine.com/archive/2009/06/lost-knowledge-timbrel-vaulting.html
Felic Candela' reinforced concrete thin shells
in the shape of ruled surfaces cast
on full scaffolding.
Felix Candela is credited with introducing large scale reinforced
concrete structural Hyperbolic Paraboloids into the practice of
architecture after WWII. He choose this particular 3D geometric form
for its simple mathematical expression, and for the fact that all
hypars consist of ruled surfaces, meaning that the double curved
surfaces are exclusively made up of straight lines. This quality
makes it possible to create the complex double curved 'umbrella's'
and composite vaults that Candela is rightly famous for, using
only straight form-work planks supported on straight beams.
Thin-shell large span construction was
popular in the forties, fifties and early seventies, and
fell then out of favour, replaced by less labour-intensive
steel truss construction.
The Philips pavilion at the Brussels Expo '58 (The first
effort at panelization of large double curved surfaces)
http://de-de.de/lectures-and-workshops/rationalization/
Post-tensioned reinforced thin shells constructed of
small precast elements
The Philips pavilion at Expo '58 in Brussels is an
interesting example of a large scale building using hyperbolic
paraboloids as a basic structural form, but, unlike Candela's
poured-in-place method, concrete prefabricated panels were used,
held together by an unusual external system of post-tensioning
cables that followed the straight-line geometry of the hypars.
I quote: http://digital.lib.umd.edu/worldsfairs/record.jsp?pid=umd:1011
"The execution of the design proved to be problematic. Xenakis'
own structural solution involved a tensile structure of steel cables
strung from steel posts at the ends of the "tent" to form the
hyperbolic parabaloids. It was rejected on the grounds that the
interior would require more solid, acoustically insulating walls. Le
Corbusier and the sound engineers wanted a structure of concrete to
keep exterior noise from interfering with the presentation. But the
complex shapes of Xenakis' hyperbolic parabaloids made it impossible
to build a conventional poured concrete structure. The solution that
would satisfy both Xenakis' ideas and the acoustical requirements of
the Poéme Electronique was a system of precast concrete
panels hung in tension from wire cables. Because hyperbolic
parabaloids are generated by straight lines, the method of using
precast panels was easy to implement. This ingenious compromise was
devised by Hoyte Duyster, the chief engineer for the Philips
project. The panels were constructed in a hangar shed from a simple
sand mold that matched the curvature of the pavilion. Once the
panels were cast around the sand mold, they were numbered, shipped
to the construction site and quickly assembled. They would hang on
steel cables strung from thin concrete ribs that were cast in place.
These ribs are visible in the photograph where the walls converge at
the ends of the pavilion. The result was a quickly and efficiently
constructed building that fulfilled the requirements of the
Poéme Electronique. "
The prefabrication of the thin-shell concrete panels making up the
Philips pavilion was done using a laborious sand casting method of
the individual concrete panels.
This precedent is particularly relevant to our proposal: a complex
surface structure was divided into individual sub elements that came
in a great diversity of geometries. Our proposed rapid prototyping
of elements could have replaced the elaborate hand work that went
into the making of the Philips pavilion.
Interestingly, in recent years there have been attempts to rebuild
the pavilion (demolished when the exhibition was over) in the
hometown of the Philips Company, Eindhoven, Holland. But this time
new robotic methods are proposed to produce the pavilion.
Make link to new philips pavilion. NEW TECHNOLOGY
Tensile roofs; the 'natural way to construct
large scale lightweight, double-curved surfaces.
Frei Otto German pavilion
Montreal
Jeddah Air Terminal
Computer modeling and form. Parametric design>> fluid design..
the algorith runs ahead of the plan and the construction, like in
the Baroque period.
Low pressure air-supported buildings; another very
efficient method of spanning large areas with double curved
skins.
High Pressure Pneumatic buildings (a
dead end .. requires large and constant input of energy and
monitoring)
Geodesic domes; a
pre-computer straight stick structure with almost standard 3D
plastic panel-infill panels.
Recent computer designed and robot constructed
freeform surface made up of straight stick and flat panel
systems:
Foster's free-form roof systems.
The complex free-form surfaces are sub-dided into small
triangular units that can be framed by short members and covered by
flat glass panels:
Examples: the British Museum roof and the Blob Eindhoven (by
Fuksas).
In the Patent Ofice roofing project the complex roof surface was
subdivided into squares, and the whole structure is supported
indepently on slnder columns.
The recently completed "Blob" in Eindhoven Holland. Flat
triangular glass and aluminum panels on a triangulated free-form
structure. Architect Fuksas, Italy.
Freeform double curved glass panels cast on robot-produced
molds, supported by a complex robot manufactured steel frame
work:
Zaha Hadid Nordpark inclined railway stations in
Innsbruck, Austria
Finally:
Double-curved architectural scale rapid prototyping
Frederico Dini, Italy and his radiolaria structure
built by Cartesian robot using snad and a binder.
Loughborough University team with Richard
Boswell.
Contour Crafting at the University of California
http:www.buildfreeform.com
CNC produced large sale double curved surfaces.
