Concrete as stereogeneous construction or an academic material?

This post is an attempt to describe a concept that I have coined – stereogeneity – or concrete as a material and as process. If you wonder how that stereo word has any relation with concrete – it may be good to know that stereophonic or stereo sound means solid sound – because stereos is Greek for solid or hard and phone is voice in Greek (news to me).

While we may forget that sound is solid – there is rarely any forgetting that of concrete. So, often, concrete is explained in simple ways as the contrast between liquid and solid. Architects explain their fascination with the material because it, at least conceptually, is easily molded like a piece of clay in the hand. Yet the truth is, of course, more complex.

Multiple design tasks for concrete
For even minimal construction projects such as student workshops this means that they have to design structural formwork principles, the concrete object/structure, as well as the process of construction – and all simultaneously. I guess this focus on the relationship between architectural technology and the expression of construction and materials is somewhat old school tectonics. But I love it – call it tectonics or not, this approach to architecture is bound to a Scandinavian pragmatic and sober tradition in design and construction. – and then it is the foundation for constructing fabric formed concrete. Everything shows – the potential as well as the ‘danger’ when the slightest pinches, the shape and position of formtie impactos, - and when things go slightly wrong. – it all shows.

[Detail of the Walking Chromosome Column by yours Concretely, 2013. The formwork is closed using a seam technique and the fabric is sweating excess mix water under the hydrostatic pressure of the freshly poured concrete]

Take off the aesthetics hat and wear what?
In order to discuss as well as develop the architectural potentials for fabric formwork it has proved necessary to define a concept to embrace this relation rather than the concrete 'results'. With only a few built examples of fabric formed concrete and thus no context for a judgement, I am really reluctant to use aesthetics or beauty as factors for evalation here because it is not so relevant if you love or are repulsed by strange bulging concrete. If you do not like it, fine, but wearing the habitual hat of the aesthetic limits the scope of any investigation.

Concrete-ness?
The pioneer in fabric formwork, Mark West, once referenced an essay by American art critic and poet Peter Schjeldahl in which he describes concrete-ness and the presence and personality and intrinsic dichotomy of the liquid and solid characteristics of concrete.
 “Concrete is the most careless, promiscuous stuff until it is committed, when it becomes fa¬natically adamant. Liquid rock, concrete is born under a sign of paradox and does not care […] 
Concrete hardens in the shape of whatever container received its flow, its momentary sensual abandon in thoughtless submission to half-loved gravity. Once it has set, what a difference! Concrete becomes adamant, fanatical, a Puritan, a rock, Robespierre – the divinity! – of the shape it comprises, be the shape a glopped heap on the ground or a concert hall, ridiculous or sublime.”

Right, liquid concrete is promiscuous – it lets itself embrace in any shape and caress by any material formwork. Solid concrete on the other hand is not to be messed with. While describing each material extreme Scheldal’s approach to concrete-ness does not quite encompass the techniques, intentions, nor materials of getting from one condition to the other.

Concrete in Greek
I turned to my friend, the Greek author Iosif Alygizakis, to help me out. With his kind assistance I wanted to coin a term that would encompass how or that concrete when cured and solid appears with signs of its becoming. Why Greek you may wonder?? – well there are two direct reasons. – I have been studying the theories of Gottfried Semper and here concrete lies between a number of his schematic labels for materials and procedures – exactly due to the different materials, techniques and conditions of the material. The concept of stereotomi (cut stone or ‘mass’) is often associated with brickwork. Tectonic with timber, Ceramics with clay, and textile with weavings or the clad/draped façade.

Greek in many tongues
The other reason is very pragmatic – for the longest time I did not know which language I was writing my PhD dissertation… Danish or English. Greek is neutral in the sense that it is used in both languages and always means the same.
Iosif dissected words and meaning through almost mathematical methods and summa summarum he created a new word based on the words for solid stereos and for becoming  - i.e. to begin to be, genés

Stereo|genés

Στερεό|γενές written without the  |  in the middle

Genés – not genesis
Genés is an ending – which comes the verb: ginomai [ginomæ]
- it means: to become – it means – to be in the process of becoming something, to begin to be
- and – becoming what?? – well, StereoThe Gr. Ginomai refers to procedure of becoming. It describes the process of the becoming of – through a procedure.
What does it become – stereo – Gr. solid – by this formulation we don't need the word fluid, liquid.
It is absolute
If it becomes solid – stereo – so, of course, it was totally understandably liquid
Of factual ideas or constructural items in order for them to become something else, something – as an aftermath as a product. – important – it is through a series of manufacture.
Stereo-geneous – the English – an adjective

[above is basically notes taken from Iosif explaining the meaning of the words and their connection]

Petro or stereo
In the US there seem to be a use of the word cultured stone as a commercial word for concrete for design and architecture – and perhaps especially for home owners. – liquid stone and cultured stone – the words can be found in Iosif ‘s other suggestion petrogenés, petro is Greek for stone. I went for stereos because, well – concrete is more than stone to me and I liked how it sounded too.

[Detail of striking the formwork for the Walking Chromosome Column by yours Concretely, TEK1 2013. The seam as well as the fabric have left stereogeneous traces.

Sekler's tectonic
The discussion of concrete as material and process is not new - and also the relationship between structural principles, materials, techniques and construction is overly described, I know. Stereogeneity is to concrete, especially in situ concrete, what Eduards Sekler’s use of the term tectonic is to the overall relation is between structural principles, techniques and the expressed physical manifestation.

So, in English, stereogenés is stereogeneity. The value of concrete as a substance is stereogeneous – it is something that develops from a liquid to a solid state.

And how to use this?? Well, in my dissertation work I have developed the use the term by discussing qualities in built concrete works by architects such as Louis Kahn, Frank Lloyd Wright, Jean Nouvel and Peter Zumthor – to describe the relation between process and materiality. For the analytical cases of fabric formed concrete I have been even more specific and looked at the role of particular details in construction: The form-tie, the frame, and the textile. Furthermore, the aspect of conditions or states between liquid and solid has allowed to focus on a particular state in the 'becoming' of the analytical cases, say the intentions behind experiments, the particular technique behind a detail versus its stereogeneous consequence at the end.

– I  hope to return to this topic and the cases in a stereogeneous light in future posts.

References
Manelius, Anne-Mette (2012) Fabric Formwork - Investigations into Steregeneity and Formwork Tectonics in Architectural Constructions, PhD dissertation, Royal Danish Academy of Fine Arts, School of Architecture.
Schjeldahl, Peter (1994) Columns & Catalogues. Great Barrington MA: The Figures.
Sekler, Eduard. “Structure, Construction, Tectonics.” In Structure in Art and Science, edited by Gyorgy Kepes, 89- 95. New York: George Braziller, 1965.

As always, please accredit me if you use any of the original points or images from this post. I'd love to know how you used or applied it and what your think.

Formwork tectonics - to round a square column

[2-meter high fabric-formed concrete column]

Formal consequence

The use of flexible molds entails a direct formal relation between the tectonic principles of the formwork structure, the type of concrete pour, and its concrete consequence, so to speak. It is a potential to develop the details in formwork construction because they are technical as well as aesthetic/form giving. On the other hand, this formal consequence means that all mistakes show themselves as well with equal power, and this is a disadvantage of the building method unless you see mess-ups as a charm. The dilemma of course is that working meticulously in construction shows high-level craftsmanship. This comes at a price in hours and wages, in Denmark 70% of the cost of concrete elements go to wages.

[Images of fabric-formed plaster model 1:4] 

Formwork tectonics

One of the student groups at the 2013 TEK1 workshop at RDAFA also concluded this from their preliminary experiments with fabric formed plaster casts. When attempting to literately tailor the fabric formwork the ruthless character of the poured plaster changed initial intentions to less controlled and little desired folds and bulges (not shown here). It took a long time to work with intricate principles and it still proved difficult to anticipate and achieve the results they desired. As a result, the students devised a formwork principle that, while simple to construct, would still result in sharp, controlled edges as well as soft curving surfaces. The principle was tested in the model shown above

  

Formgiver and structure

The storyboard shows the steps of constructing the column and the simplicity and tectonics of the structural formwork principle. The title is Compression and Expansion and refers to the role of the formwork sheets and the consequence on the poured fabric mold. I love how the interlocking and formgiving mdf-sheets are also what holds up the fabric tube. The principle means that the column has a square footprint and always two flat surfaces and two curved ones, i.e. quite a complex geometry.

 

[Left: the formwork structure ready for the pour. Right, detail of the formwork structure before stripping ; bits of cement has filtered through the fabric along with excess mix water during the pour.]

[Sketches from student report showing the principles and the steps of constructing the formwork]

 

Creases and shifts

Despite their work at simplifying the process for ultimate control, for the resulting fabric-formed concrete column, students were unhappy about little creases from the fabric as well as the asymmetry of the bulges. Especially the bottom has uneven bulges, which could have been avoided by adjusting the fabric tube before and during the pour, as well as working the concrete from outside the formwork – simply moving the fresh concrete by pushing against the membrane mold. Note, however, how identical creases can be found on the surface of the plaster model cast using the same principle.

This first meeting with concrete and principles formwork tectonics for first-year students is promising. If you are in Copenhagen, swing by the quay behind the RDAFA and check out the columns.

Credits

Work and drawings by: Oskar Mannov, Sidsel Petersen, Nora Ødegård, Cuong Tran, and Toke Ridderson.

TEK1 2013 concrete workshop organized and taught by Finn Bach, Tenna Beck, and Anne-Mette Manelius (yours Concretely) for the Institute of Architectural Technology at the RDAFASA

PS

I have written much more about formwork tectonics and stereogeneity (concrete as material and as process) in my PhD dissertation

Workshop - Draped Concrete in the Rotation Column

This Rotated Column was designed by students and constructed during the last weeks' TEK1 workshop at the Royal Danish Academy of Fine Arts, School of Architecture

[Rotated fabric-formed concrete column]

 It is easy to see the principle behind Rotation Column: the formwork tube is rotated to create a spiral shaped column. The top and bottom are rigid boxes to supply contrast.

The formwork membrane is attached to the top and bottom and furthermore zip-tied to the reinforcement inside.

[Detail of the formwork before the pour. The series of wires is actually a very simple and strong way to make a seam in fabric formwork. The to ends are rolled up and pinched with twisted metal wire or zip-ties]

 While the team had already tested the principle in several plaster casts where the fabric got stuck in the plaster, they kept this principles and optimistically hoped that the concrete would not react the same way at the large scale.

The team had to use a heat gun to strike the formwork stuck in the concrete. At the end a wonderfully soft-looking column came out.

The Rotation Column (Draped Concrete) was part of the TEK1-concrete workshop in 2013.
Members of the Team: Alexander Egebjerg, Aron Wigh, Markus Nilssen Kinstad, Albin Arvidsson, Lea Møller, Dahlia Dudas
Supervisors: yours concretely, Finn Bach and Tenna Beck

Fabric-Formed Concrete Columns

Just finished a wonderful workshop with first-year architecture students at the Royal Danish Academy of Fine Arts in Copenhagen. The theme of the workshop was columns.
In the past four years I have organized and taught a number of similar full-scale workshops but never written much about the workshop frame. This post will go through some of the thoughts behind the elements and activities of the workshop.

[The family of fabric-formed concrete columns]

[The formwork structures on pour day with the concrete pump in the background]

Studying concrete in relation to its mold
Concrete is studied best in relation to its formwork, as material and process. The use of fabric formwork is an excellent tool to introduce concrete and formwork principles in order to enforce an individual and curious understanding of what concrete and the process of casting is all about.

The concrete workshop is a highlight of the TEK1 course, a mandatory four-week course about architectural technology. This year, 35 students (a quarter of the class) were in my workshop. 

Columns

The theme of the workshop was columns. As the most basic structural and architectural element the column is loadbearing as well as the defining space. The student's approach varied greatly. And their focus sprung from either the textile principles of draping or sewing, or principles of the construction process and how to use minimal means and simple process to construct their formwork.

For a fabric-formed column the main objectives of the formwork is a) contain concrete, b) stay in place (erect), c) additional sculptural features. A and B remain the crucial aspects but the point is, of course, that by erecting the formwork structures in a clever way, the formwork-tectonic principles also have a direct formal consequence on the concrete column. Furthermore, the closing detail or seam of the fabric is important as well. Basically, focus remains on a few important details and their effect - as ornament or as 'invisible'

Afternoon 1: Brainstorm

First step in our workshop is a one-hour brainstorm. At this workshop, 6 groups sketched and played with fabric for an hour after which we have a short pin-up. The point is that by sharing these initial ideas creates a pool of knowledge as well as a number of themes and categories to discuss. Themes of concrete's sculptural form, textile notions, and design principles derived from construction become clear from discussing the sketches and ideas. Looking back now it seems that this initial categorization of approaches has helped the teams to remain clear - at least the themes are pretty clear in their work, anyway.

Afternoon 2: Plaster

The workshop is all much about making. And about making something fast. 

A great way to make decisions and learn from principles in fabric formwork, is to do small scale casts in plaster. This is a method practiced at CAST and it works really well in the student workshops. For this workshop we had a plaster lab allowing us to mess around with plaster and the student teams were super enthusiastic, playful and productive.

[Detail of plaster cast in a fabric mold with impactos]

[learning by doing, casting plaster in fabric molds. The blow-out experiences are much nicer to experience first at a smaller scale]

[Selection of plaster models cast in a few hours]

Day 4: First Concrete mix and pour

As a way to change scale and focus from plaster to concrete, it was fun and appropriate to build simple formwork frames as well as mixing and placing concrete, heavy as it is. Each team had their plinth and were given U profile reinforcement to place according to their column design.

It turned out excellent to leave the formwork boards on the foundation during the entire workshop. In this way the column formworks could be fastened to the ground. 

[Students placing concrete mixed in the mixer in the background. The wooden formwork boards allowed the teams to attach their formwork bracing]

Constructing full-scale formwork structures

Producing several plaster casts allows teams to discuss construction techniques as well as the expression and geometry of their finished column. The full-scale work entails a different and much more material oriented approach. One team wanted to stitch their formwork together and had to devise a special needle tool to do it at this large scale, with a thick nylon rope, and in a controlled manner.

[Student group discussing their principle of stitching as an element of formal and technical form tie or restraining]

[The stitched formwork. The column becomes more like a wall or at least a double column]

[Over the top but great. Our 2 cubic meters of concrete came with a pump as well as a truck. The 'pump man' was the coolest and a very patient guy]

[Concrete fever - Keeping cool and waiting for concrete]

[The rope remains embedded in the concrete. The team managed to remove the fabric around the stitches]

Acknowledgements

The concrete factory Unicon sponsored the concrete pour

We received cement from Aalborg Portland to mix and pour the foundations

Supervisers and organizers: Anne-Mette Manelius (yours concretely), Finn Bach and Tenna Beck.

Stitched Column (Betonsyning) team: Agnes Garnow, Marcus Innvær, Mikkel Kühnel Witthøfft, Alexander Kristensen, Rasmus Feddersen, Michael Brandrup 

Prototyping Architecture - exhibition and conference

[Image of the fabric-formed concrete column by yours concretely in the exhibition space for Prototyping Architecture. Photo by Agnese Sanvito]

I am looking forward to presenting a paper at the Prototyping Architecture conference in London.  The conference is organized in connection with an exhibition of the same name, which is a collection of a broad variety of architectural 'prototypes' ranging from a 3d printed violin that I am not so certain of how to categorize architecturally, to a 1:1 mock-up of the Loblolly House by Kieran Timberlake, to a number of research objects testing new manufacturing techniques and materials. The field of fabric forming is based on prototyping in the sense that every new experiment is the prototype of material and process.

The first exhibition venue was at the University of Nottingham. I contributed to the exhibition there with the design and production of a prefabricated fabric mold, which I then brought to the site (the prototyping hall at the school of architecture) in a bag , unfolded it there and arranged a concrete pour. In lack of a better name, I refer to the column as the PA Column (PA as in Prototyping Architecture)

[the formwork hanging over the fabric-formed column at the exhibition venue at the University of Nottingham. Photo by Victoria Gaskell]

Here follows the text that accompanies the exhibited object: Fabric formwork is a new construction method for concrete structures that utilizes sheets of fabric as flexible, lightweight moulds. Based on a recently completed PhD project about the architectural potentials of fabric formwork for concrete, the fabric-formed column designed and constructed especially for the Prototyping Architecture exhibitions is the investigation and material prototyping of a lightweight, prefabricated fabric mould, which unfolds to be cast on site. The three-legged concrete column is form-optimized for stability and constructed with minimal means.

The principles of tensioning the fabric, of restraining it, and placing concrete have a direct formal consequence as a material dialogue between relaxation and control; thus the technique encourages an architectural understanding of concrete as material and as process. Essentially the exhibited prototype must then be understood as the formwork, the process, and the concrete object, and the contribution discusses the future of industrialized concrete architecture by emphasizing the prefabrication of intelligent, and lightweight moulds as an alternative to ‘dumb’ and heavy concrete elements.

With the high ceiling of the exhibition venue at the Prototyping Hall of University of Nottingham the mould was exhibited, hung next to the concrete object and details of the sculptural concrete object could be compared with its two-dimensional textile origin. In London, the ceiling is much lower and there was no room for the formwork, which is really a shame for the understanding of the piece as a prototype.

[The homemade flight bag containing the entire formwork structure: wooden braces/form ties, metal clamps, tools, everything besides the concrete mix]

[yours concretely hand-filling the formwork aided by the great student workers in Nottingham]

[Detail of the PA Column after it was moved to the Building Centre in London]

The title of my presentation is Fabric Formwork - Prototyping concrete as material and process - and I better get back to finishing it.

Here's the link to the program of the conference - I'm very excited to go.