Formworks - Assignment 01

New Space Through Plasticity 

Miguel Lantigua

Spring 2013

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The inauguration of concrete casting through rigid formwork techniques in itself radically altered the construction industry, consequently a large sum of the architecture produced, especially in the latter half of the 19^th and early 20th century since the rediscovery of concrete. Indeed the adaptation of this building material inevitable attributed to the proliferation of concrete architecture. Despite its revolutionary break through, techniques in formwork construction had not remained natural. Fabric formwork, which one can argue as the second most critical phase of the material’s development, is a building technique which deploys the use of structural membranes, that is, fabric, as a means to generate concrete components through the molding process. Yet while such transition/ method of formwork drastically alters the image and possibilities in the use of concrete, what remains consistent between rigid and the flexibility that is fabric formwork is its fast production, economics, and manipulation opportunities. However, it is critical to not fancy formwork techniques ‘merely’ per its economic qualities, rather what makes this method of construction so appealing is the opportunity to use the plasticity of concrete, which in the case of fabric formwork, is enhanced in possibilities made by the inherent properties of fabric, to generate dynamic forms and spaces previously unconceivable and achievable in rigid formwork techniques.

Fabric formwork finally allows us to ‘further’ apply conceptual architectural approaches, particularly those which deal with more relatable spaces, by allowing concrete to be as free as it truly is, that is, its ability to take any shape, rather than be confided to rigid boarders which lake the reliability to us, specifically the complexity that is our bodies. In a nutshell, formwork in general should not be deployed on the mere basis of its fast pace economic qualities. More than this, ‘fabric’ formworks unlike the limitations of metal, wood, and brick construction, which are rigid components, allows us to contribute to how we generate space through reinventing how ways of producing both conceptual and structural systems.

The following projects, accompanied with links, are in support of the above argument, in fact, deploying the very conceptual and structural notions mentioned. Please do look into this further and learn of the space and conceptual possibilities made possible by fabric formworks:

Note: Image captions are of the project's author

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This first project inspired by Eadward Muybridge, explores the role of the human body in the formation of space through the use of concrete fabric formworks, that is, first recording the movement of bodies in space.

Excerpt: : The idea of physically recording the movements of a body within a space spawned a series of photographic studies using motion-capture photography pioneered by Eadward Muybridge. Combining these methods with more recent digital technology helped record and map how the body occupies an interstitial space. The actions of sleeping, walking and sitting within a defined space were recorded in plan and elevation with a camera. Combining the individual frames into a composite image manifested the ghost of the space once occupied by the body.

Program sequence of interstitial space in plan 

Flexible fabric formwork mechanism 

Internal walkthrough of the defined interstitial space

Output of concrete panels created by the machine

This second project asks the question of: what a beam and column could become. A beam needn’t be joined to a column as two individual pieces, could they be cast as a single element using sewing to stitch and shape the formwork using sleeves?

In which they  explored the possiblities of:  a more rational form might result if each element was cast together as a single entity using the qualities of the fabric to dicate the form. Our joint was made in the formwork itself.

Project link: http://richardbush.wordpress.com/     

Video: http://vimeo.com/53981192 

Fabric Forming: Understanding the Method Assignment 1

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FABRIC FORMING: UNDERSTANDING THE METHOD
Fabric form making can be understood as a response, perhaps an evolution, to traditional concrete construction. 


By hybridizing both technologies - concrete casting and fabric forming - new possibilities of construction emerge, possibilities that explore the inherent qualities of both. Concrete, for example, is a material that is naturally solid, dense, strong and stubbornly permanent. Thus, contrasted with the qualities of fabric - soft, free-forming ephemeral material - one, then, can exploit this combination resulting in a frozen dynamism and conjuring a dualism between both opposites. 

Conceptually and practically, this method is questioning our traditional conception of what it is to make and assemble. Since the early 1950’s, modern architects architects have expanded these questions by reconsidering the role of form. Thus, the following is a collection of images by designers grappling with this method. 

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Erwin Hauer, Austrian born sculptor, began, in the 50’s, to explore infinite continuous surfaces. From these, perforated modular structures developed that lent themselves to architectural usage. He continued to develop these patented designs along with the technology to produce them, and installed the modular, light-diffusing walls in buildings throughout the United States and seven other countries. These designs are listed in domus 1928-1999 among the quintessential works of modernism.

ERWIN HAUER WALL DESIGN III, NURBS MODEL

ERWIN HAUER WALL II, CONSTRUCTION 1953

Jeremy 1.

Dali's diagram of the PCM method

1.

In Delirious New York, Le Corbusier’s fondness of concrete as the material choice of architectural modernism is compared to the Paranoid Critical Method which Dali used as a creative process.

Concrete is hard, but was once infinitely lenient. That something so strong and rigid can have the appearance of an easily manipulated substance is the basis of its potential to be something uncanny and interesting. Probably, this notion is only a result of the current state of technical development of concrete casting, and the uncanniness is only a misunderstanding of the true potential of the material.  

Concrete is heavy, and flows freely in its uncured state, but needs a temporary house that will hold it in place, that will let it cure for several weeks of time.

The vast majority of concrete formwork takes advantage of the stiffness of a material to harness this weight and viscous pressure of concrete to give it a temporary housing. Shutter ply, various kinds of rigid plastic or foam.

Fabric is a material form that, in most cases, completely lenient and elastic to some (sometimes great) degree, thus only carries tension. Fabric concrete casts rely on the weight and viscous pressure of the body of the concrete fluid, and the dimensions + elasticity of the fabric for the form of the product to be determined, or found. It swells and drapes, hangs and expands as forces are applied to it making it inherently more difficult to control with high levels of precision.

Photo credit Toshio Shibata

Decorative columns. via

2.

The first order of fabric casting seems to take on its moldability to create forms that are generally not associated with hard materials, for example to stabilize a fagile ground condition. The columns from C.A.S.T.’s research are interesting as the forms are uncommon in concrete, but they do not perform structural functions, and are purely decorative.

Material System Organization - P Wall. 2009 @ SF MOMA. via

In the case of P wall the formworks take advantage of the ductile nature of fabric, which results in a system that combines elastic fabric, rods and the weight of the material for a configurable setup. each panel is, although made from the same system, a variant of each other.

C.A.S.T. - Flying Vault. via

3.

With a more practical goal in mind, this freeform property of fabric can be used to find optimal geometries for specific structural tasks through catenary exercises.

Here, in a research conducted by C.A.S.T., a square fabric is stretched downwards from a square frame downwards to maintain the modularity intact, resulting in folds or ridges in the fabric where concrete is directly cast off of. While the overall curvature is the response of the fabric to the weight of concrete (or gravity acting on concrete), something that can be achieved with chains or ropes as Gaudi did, the ridges, forming perpendicular to the applied forces, are something inherent to fabric formworks.

Balloon cast porcelain by Miwa Koizumi via

Pre-tensioned thin shell panel by C.A.S.T. via

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Here a new possibility seems to be in casting thin shells. While an easily achievable property in other materials like porcelain, similar to concrete but with a fundamental difference in its hardening process, shell casting, or single sided casting of concrete is a relatively new frontier in concrete. there seems to be a possibility for an even more efficient structural application in this method. In this example a fabric is pre-tensioned to create matural fold ribbings, where a shell of concrete is cast off of.

Fabric Formworks / Research

FABRIC FORMWORKS : 

Fabric formwork is a building technology that involves the use of structural membranes as the main facing material for concrete moulds. Unlike traditional formwork, the material is highly flexible and can deflect under the pressure of fresh concrete. The resulting forms exhibit curvature as well as excellent surface finishes that are generally not associated with concrete structures. 

Fabric formwork was invented proper in the Industrial Revolution but was also used briefly in the engineering of the Roman times. Architect and engineer Vitruvius, created cofferdams using two retaining walls that are filled with clay in woven reed baskets. Vaulting with a plaster finish was also constructed by the use of reeds tied together to form the lower surface on which a sand mortar is applied. Fabric formwork was until this point,only for  utilitarian purposes and started to make more of an architectural influence with Miguel Fisac, a Spanish architect, in the 1950s. Fisac was well travelled and found this own unique style. 

Diagram of Evolution of Fabric Formworks

Historical Review in Detail :  History


Interest: 

The production of thin, doubly curved shell elements, which are difficult to produce and reinforce with conventional means. These shell elements can be used as façade panels, self-bearing roofing structures, or permanent formwork elements. In the latter case, large spans can be realized, with very appealing design and a perfect surface finish.When adding flexible and dense glass fibre textile reinforcement to a fine tuned mortar, a ductile cementitious composite with tensile capacity can be produced. Hence, the steel reinforcement can be omitted and the freedom of shape, inherent to fluid fresh concrete, can be fully exploited. Creating Shell elements, using Geotextiles for enforcement. 

FormFinding

Some Examples :


1) Fabric Formed Hyperbolic Paraboloids
Hyperboloids

2) Structures:
These could be simply artworks or a way to carry complex systems within a building. 
Fatty Shell

3) Larger infrastructure Projects:

Large Span Cable Net and Fabric Formworks Bridge

This project investigates the feasibility of using large cable-nets with a secondary system of geotextiles as formwork for concrete shells. This new concept builds upon existing architectural vocabulary, ideas and advantages found in fabric formwork technology, cable-nets and tensioned membrane roofs, to allow for large-scale, long-span structures.

Bridge

4) FDM : Force Density Method for Fabric Formworks:

Design and analysis of fabric formworks

Fabric formwork is characterized by the use of coated fabrics or geotextiles as the main material for a concrete mold. This method allows concrete`s inherent fluidity to create new forms of concrete architecture and aesthetics. The design considerations for these formworks are similar to those in the design and engineering of tensioned membrane structures, involving the interaction of prestress, non-linear material behavior and the support conditions. Additionally, fabric formwork has concrete pressures, contact analysis and fabric wrinkling as complicating factors. Through combinations of form finding and analysis, this research aims to develop new tools for the structurally informed design of fabric formed structural systems.

5) Lightweight Structures

Lightweight structures video

6) CAST:
The casting of a full-scale panel using concrete requires finding a fabric capable of supporting the weight of the wet concrete. For this purpose, a geotextile fabric made of woven polypropylene fibers was utilized by C.A.S.T. The flexible fabric material was pre-tensioned in the formwork and assorted interior supports were added. Depending upon the configuration of these interior support conditions, three dimensional funicular tension curves were produced in the fabric as it deformed under the weight of the wet concrete
Cast



7) Geotextiles & Fabric Formworks

Woven PP and PE are produced with high tensile strength and low elongations. They have high capability for filtration and distribution of load and manufactured from individually woven, ultraviolet (UV)-resistant Polypropylene fibers. Geotextiles are produced as non-coated or coated using a layer of PE.The main use of Geotextiles is the stabilization of soil but some builders, architects and researchers have adopted them to be used as formwork for concrete.

In 1960 Felix Candela used burlap (jute) to form his concrete shells. A decade later, Miguel Fisac used plastic sheets as fabric formwork and in 1980’s Bindhoff and Lamberton used Nylon fabrics. PE and PP woven fabrics became commercially available in mid 1980’s. Use of PE and PP woven fabrics as formwork for concrete was introduced in late 1980’s by Mark West and Richard Fearn more or less at the same time along with Kenzo Unno who used a plastic construction scaffolding netting as concrete formwork.

In order to study specific effects on concrete strength and quality obtained by using commercially available woven polyolefin fabrics or geotextiles, it was necessary to form concrete cylinders using a variety of fabrics and concrete mix designs. A fabric used as concrete formwork must be strong enough to carry the hydrostatic pressure and the hoop tension imposed by wet concrete. In addition, it should be adequately porous to allow discharge (bleeding) of the excess mix water from the fresh concrete while preventing the loss of solid elements (fines) particularly cement and flyash particles.

8) Zero Waste Formworks



Unno's 'zero-waste' formwork uses a reinforcement cage to support the fabric, so bracing and propping elements are not required. For insulated construction, the fabric, together with rigid polystyrene insulation boards, forms the shuttering. Furring strips – long, thin strips of wood or metal –are used as support, and remain in place after the concrete is formed to provide fixing points for cladding. After use, the fabric, a woven polypropylene geotextile, can be washed and used again.

Other Interesting Links:

Concretely

Retaining Wall Project

Formworks - Assignment 1

 With his suggestions for the use of tied reeds in the casting of concrete, Vitruvius may be one of the first people to ever describe a type of flexible 'fabric' formwork.  Reed imprints found in the underground 15th-Century concrete vaulting of Villa Medici in Rome suggest that these flexible plants were indeed used to create a lightweight formwork that could be easily maneuvered in tight spaces.

Reed centring in the Roman concrete vaults beneath
Villa Medici, Rome.  Reproduced by permission of Matthew Bronski. 1

It was not until the Industrial Revolution, however, that a true fabric formwork, as we know it today, first appeared.  Attributed to German architect / builder/mason, Gustav Lilienthal, the method of pouring floors into suspended fabrics saved on centring, materials, and labor.  Further, the geometries of fabric-formed concrete is more efficient--the catenary curves of the concrete follow the bending moments and also save around 20% of concrete needed in a beam.  

Fabric formwork progressed quickly and was given a geotechnical application for hydraulic purposes in canals and embankments.  

Ybarra Hotel Tres Islas (1972). 

Reproduced by permission of Fundación Miguel Fisac. 2

20th-Century Spanish Architect Miguel Fisac was arguably one of the first people to acknowledge fabric formworks for its aesthetic qualities--not simply its structural, utilitarian functions.  He created hollow, bone-like beam structures that turned away from wooden formwork surface patterning, and he did his best to express the tactile, plastic qualities of concrete.  In some ways, Fisac's expression of the textile nature of the material within his facade panels is reminiscent of Frank Lloyd Wright's textile blocks, which ironically were not made using textiles, but rather complex rigid moulds.  Still, the notion that a heavy, solid material could be used to express delicate, intricately patterned materials (and could do so in a light, modular way) was revolutionary.

Frank Lloyd Wright Textile Blocks. 3

Frank Lloyd Wright Textile Blocks Connection Details. 4

These are qualities with which designers have continued to experiment.  The invention and mass-production of durable synthetic materials in the late 20th-Century changed the practice of fabric formworks in an extraordinary way.  Kenzo Unno, Mark West, and Rick Fearn have each pushed the limits of concrete in aesthetic, technical/structural, and environmental ways.  Aiming to have no material waste, and to enhance surface material quality have been driving goals.  Further, experimentation surrounding structural optimization has shown that fabric formworks can not only produce voluptuous structures, but seemingly impossible thin forms as well. 

CAST Truss, University of Manitoba. 5

SFMoMA - P_Wall (2009). 6

Additionally, the increasing use of parametric software and digital fabrication techniques has made it much easier to design and create dissimilar modular panels.  Concrete must no longer be though of as a stiff, bleak medium of Modernism, but rather, as a malleable, exciting material to be constantly reinvented.

SFMoMA - P_Wall (2009). 7

FattyShell, a student project using rubber and concrete. 

Reproduced by permission of Kyle Sturgeon, University of Michigan. 8

Image Sources:

1. http://www.fabricforming.org/images/papers/Veenendaal,%20D.%20History%20and%20overview%20of%20fabric%20formwork.pdf

2. http://www.fabricforming.org/images/papers/Veenendaal,%20D.%20History%20and%20overview%20of%20fabric%20formwork.pdf

3. http://www.santamonicapropertyblog.com/wp-content/uploads/2011/08/East-Wall-detail-2-edit.jpg

4. http://sdrdesign.com/blockTNH4.jpg

5. http://www.umanitoba.ca/cast_building/assets/images/fabric_formwork/truss/CAST_Truss_View_SLIDE.jpg

6. http://matsysdesign.com/category/projects/p_wall2009/

7. http://matsysdesign.com/category/projects/p_wall2009/

8. http://www.fabricforming.org/images/papers/Veenendaal,%20D.%20History%20and%20overview%20of%20fabric%20formwork.pdf

Assignment 1: Research

Fabric formwork allows more of a dialogue between the formwork and the concrete being poured.  In the final structure you are able to read not just the form but the process of the pour and how the structure that held the pour was created and supported.  Fabric formwork brings concrete back to its origins by allowing it to fluidly create a form.  The image below shows the fluidity of the concrete as it bulged within the fabric formwork.

Fabric formwork is beneficial in how it is less expensive, complicated, and labor intensive than using rigid formwork.  Fabric also gives the structure a nice finish, thus eliminating the need to return after the curing to refinish the material.  Different fabrics used can produce slightly different finishes to the concrete.

The three dimensional curves that are created can also be altered by adjusting the elasticity and prestress levels of the fabric membrane.  The ability of fabric to let excess water leak out also makes the concrete form stronger. 

Fabric membranes can only resist tension forces, so some sort of framework is needed to hold the fabric in order to achieve the amount of deflection one is aiming for.  Japanese architect Kenzo Unno has developed two different framework methods for supporting the pouring of concrete walls.  The first method is the Frame Method which involves using linear elements held in place by bracings to control the deflection of the fabric. 

The second method, the Quilt-Point Method, uses form ties and washers to control the deflection of the concrete.  These methods are both successful in preventing the wall from becoming one giant deflection.

Details can also be easily integrated into the fabric formwork casting process.  The fabric formwork is able to deflect around frames or joints so that smooth connections are made between elements.  In the images below of the Nakashima “Stone Renaissance” house, a stone was inserted to create a seamless joint around the protrusion.  In the second photo where the concrete wall meets the glass, a blockout was placed inside the fabric formwork to form a notch where the glass would then be able to be inserted.

Sources:

http://www.umanitoba.ca/cast_building/assets/downloads/PDFS/Fabric_Formwork/Kenzo_Unno_Article.pdf

 

http://www.concretedecor.net/Articles/CD1001/CD1001_Fabric_Formwork.cfm

http://www.fabricforming.org/index.php?page=about