Fabric formed concrete benches

As a direct continuation of the previous post on an upcoming concrete workshop in which students will design and produce benches, here's another couple of examples. Bench could be read as just another word for span - it's just a matter of scale, whether the span holds a person or a floor, right?

[Image of fabric formed beam - could be used as bench, by CAST at University of Manitoba, Canada]

Fabric formed beam - or bench
Above image is cast as a beam of 22 metres. - I've sat on it, so you could use it as a bench, I guess - What's interesting about this piece when it comes to producing a long span is the fact that it was cast in just two flat sheets of fabric!
The beam is actually quite old and the good people at CAST (very firgurative abreviation for Centre for Architectural Structures and Technology at the University of Manitoba).
Do read more about the pioneering work at CAST and professor Mark West here.

[Image of Buenos Aires concrete bench by Grupo Bondi, 2010]

[Detail of concrete bench with aluminium clamp tube, photo from Grupo Bondi]

Fabric formed furniture
The pieces of furniture by the Argentinian Grupo Bondi definitely look familiar. (see the post on the Ambiguous Chair here). The guys have been working with flexible molds for some years and, opposed to the research pieces done elsewhere, there's actually price tags on most items.

The bench weighs 145 kgs. The concrete mattress sits on iron legs and will fool you with the apparent upholstered bulges. Previous work could be shells? The cushion below is only 39 kgs according to the designers.

[Concrete furniture by Grupo Bondi]

I bet that those pieces must have been cast in fabrics or similar flexible formwork. Do check out the web site for more design ideas cast in flexible formwork and products to order.

The stunning shell solution
I need to show you a more recent project from CAST. Ronnie Araya works there as an assistant Professor and did these beautiful thin shells that also have some spin off work for furniture. - the overall interest is architectural structures - but, as mentioned befor - working with technologies at a furniture scale is an interesting starting point - and something that is more likely to sooner have a life outside the studio than large load bearing structures.
I wrote more about this piece in this previous post

[Image of rigid fabric formwork and the cast shell - I think this is a scale model in plaster. Image courtesy of CAST]

[Image of full scale PVC-coated mold ready to be cast with GFRC, Glass Fibre Reinforced Concrete, Photo from CAST].

Read more about the stunning shell work at CAST here. The words is that the studio is doing a project with shells like these - so I guess work does get out of the lab! Can't wait to see it!

One Gaudí beam and fabric formed shells

At the recent Structural Membranes conference in Stuttgart, Ronnie Araya presented a paper on the current research at CAST. This summer Ronnie and his crew have produced a number of shell structures in a sort of composite formwork created by tensioned sheets of fabrics and padded frc. The methods are low tech and fairly simple; the structures are effective in using only a minimum of materials to obtain structural properties; and the images of the structures are just beautiful.

 

[image: formwork and cast shell structure in fibre reinforced conrete (frc) done at CAST, Winnipeg, Manitoba, photo by CAST]

I spent this past weekend in Barcelona and got the chance to visit Casa Batlló by Antoni Gaudí. A lot can be said about the structures produced from the mind set of the brilliant Catalan architect, however, I want to point out the immediate ressemblance with the work done at CAST. I know Gaudí is a huge source of inspiration af knowledge to CAST; references I've come across have been concentrating on the design work using hanging chain models and catenary curves.

The image below shows a beam or possibly just a shell covering the details of the top of the skylight - more on that later - When I saw this part of the structure I was stunned at the close ressemblance to the works Ronnie had presented only weeks before.  The actual construction methods are pretty different as far as I'm informed. Gaudí used brick and plaster to a great extend in this house - I'm pretty sure that the simplicity of the CAST methods (using technical textiles and frc) deviced a century after Batlló would inspire the old master - both certainly inspire me.

[image: Beam across the atrium in Casa Batlló, Barcelona, photo: Anne-Mette Manelius]