Frame and Form

In this installment of the library we talk about the exhibition Bones Various. This shows part of the architect's work Miguel Fisac Serna (1913-2006), specifically, a group of precast concrete pieces whose shape is similar to bony structures.

Santa Ana - Miguel Fisac

Jaroslav Pelikan hit upon the idea of such sites following a creative process whose main premise is summarized in the following quote:

“Concrete is heavy, The drawback is that you can say, and then, where it does not work, non-working areas can be removed”

Miguel Fisac

The fact that resembled parts of cow bones Fisac gave confidence in the appropriateness of your idea.

Several bones - different parts

With these pieces Fisac getting very intuitive link between structure and form, or saying it other way, function and form. Thanks to bones separation between purely resistant elements and architectural cladding and insulation vanishes.

Cover Hydrographic Studies Center - estructura y forma. Photo of Alex del Rio (2007)

Fisac bones are a set of pieces in which the possibility to shape the concrete being used to its limit. The bones have great expressive plastic sculpture by acquiring additional condition to the structure.

The bones are divided into two groups; the first corresponds to parts postensadas (section asymmetric). Fisac was a pioneer in Spain of applying post-tensioning in building (so far only been applied to the field of bridges). From the standpoint of constructive (for large spans) the voussoirs which are post-tensioned elements can be transported more easily than girders as assembly work can be done in.

Part CEDEX - Post-tensioned concrete

The additional advantage of post-tensioning is the fact that the trajectory of the active armor can be designed to counteract the effects of permanent charges under various sections of the structural element thus optimizing the function of prestress.

Curved path of post-tensioned to compensate for the effect of dead weight

The other parts are pretensadas (symmetrically). In these pieces the active armor is straight and therefore not as easy to counter permanent loads unable to adjust the trajectory of the cable. Instead, symmetry of these parts provides great lateral stability to the center of gravity coincide with the shear center.

Part Valladolid - Prestressed Concrete

Part Valladolid - Santa Ana

The difficulty of making constructive pieces of concrete hollow thin wall is not negligible and deserves special mention. The formwork system, that developed in both types of parts denoted admirable creativity and inventiveness. Fisac surrounded himself throughout his career in technical and creative entrepreneurs and innovators like Richard Barredo and Vicente Peiró. These structural solutions are often applied long before the regulations covering these technologies.

Preparation of formwork

Dovelas part Trapeze

It is important to analyze the contribution of Fisac in the context in which there was. In the Spain of autarky that had to invent it did not exist with the available. Competition was limited as the industrial. Although this paradoxical situation favored the creativity and the ability to realize their own creations.

In this sense Fisac is similar to other great designers and builders as Freyssinet, Maillart or Candle in which innovation, design and economic competitiveness of the proposed solution was its major asset.

Metadata:

Web Exposure, very complete page on which the exhibition curator Fermin Gonzalez Blanco shows in detail the characteristics of each of the bones and multiple additional material. Most photos and images from this post have been extracted from this page.

Exhibition Catalog, highly recommended reading which is covered in written format the elements of the exhibition.

Dossier of exposure (PDF)

Official website of the Foundation Center Fisac Serna

Jaroslav Pelikan on Flickr

Several bones in eyes of the 2 (Video)