Concrete Projections

February 21, 2012

The gallery shows some pictures of what started a fun attempt to communicate the method and technique used to construct a material structure in an immaterial way. Using a projector secured to a balcony from high over head, we showed the location of the voids, the location of the steel reinforcement and some other imaginative patterns that completely changed the perception of the concrete surface.

 

 

 

 

Advertisements

Single Cast Fabric Formwork

December 3, 2010

Final Piece

Concept of a single cast structure:

Markings for reinforcement and guides for pouring as well as letters matching up to the holes in the top plate which came in very useful.

It is inevitable that architectural components require connections. However, the position of the connections is required to be in the best interest of the structural element, form, construction and aesthetics. One of the other reasons for pre-fabricating and casting separate pieces to fit together is for transportation, but of course concrete can be poured in situ! This posed a question about what was possible to achieve through the process of stitching – essentially tailoring fabric to generate a form.

We admired the past work done of the previous years, but were critical of the techniques used to connect fabric formed elements and argued that quite a few of the connections were infact unecessary. The qualities of fabric formed concrete is to use its inherent properties of the fabric to manipulate the plasticity of concrete.

Our position asked the question about 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? We thought 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.

The formwork complete and stiched laid out and marked up ready for hanging onto the frame. It can be folded up into a backpack.

Additionally, such a concept opens up new tangents and industrial possibilities in concrete construction methods. Suddenly a piece of fabric formwork can be specified (using the guiding principles), stitched in a textile factory off site, transported easily in a bag to a site, unfolded, hung into position with the use of simple scaffolding and minimal timber structure and cast on site as a single entity. Our aim was to prove this concept with a large free standing singularly cast enclosure: a wall with two columns.

Sleeve joint after casting.

The video of the frame and formwork construction, the pour and the final peel can be seen at the link below.

http://www.youtube.com/watch?v=-8rIywPBTtA

Finished casting.

End Elevation

Our prototype structure was successful with only a couple of complications due to not quite getting one of the columns verticle when we cut the holes – something that could be easily corrected by using a pole as a guide. As a result, the fabric at the sleeve wasn’t tense enough and risked a lack of concrete in the joint. Our solution was the tie the column back to the frame, to straighten it up and put the fabric into tension again. The result is a jaunty slender column that is quite appealing and has the remains of the rope marks on the surface as another reminder of process.

There is an even surface finish with very few imperfections over the whole surface. One area of imperfection however is towards the base of the wall that has not compacted fully because we were distracted by two burst cotton stitches, positioned to control the mass. The bottom most stitch survived, which proves the concept that it a simple 1cm square stitch can be used to control the mass and prevent it bulging. In the case of the other two, we determined that we weakened the fabric around the thread by over sewing it – making the stitch stronger than the cotton itself, resulting in a tare under the pressure of the concrete. We patched the breaches quickly, but the ‘bullet holes’ remain as evidence on the surface. However, it is interesting to see the difference in mass compared to the successful stitch at the base of the wall.

Another slight area of improvement is in the footings, where we were unable to access the concrete during the pour and probably didn’t vibrate the base enough to get a full compaction. The result is that some of the aggregate around the edge comes away and the concrete is imperfect around the base, but it is not in any structural danger.

The sleeve joints are expressed very well

View looking down the wall showing the bulges and the compression

It is possible to observe some beautiful abstract forms that evoke Dieste's work - all as a result of process and knowledge of technique

Looking through the structure. Detail of the surface finish and stitch pattern visible

It is fascinating to walk around the structure and look through the structure at different angles to appreciate the slenderness and the geometry. A space is defined by the structure, that gives an architectural language determined by the positioning of material.

 

In the context of our unit’s title Distructive Technology: Material Immaterial – the discussion that formed a critical part of our design process, that now only exists as notes and sketches, represents an immaterial property of a material concrete structure. In the process we have developed a language, a code, to work with this material and discuss its process and potential wtih other people. We have developed an understanding between material and immaterial.

Production makes perfect.

November 20, 2010

Photo from our intermediate review

Without the doing there is no thinking. Quantity results in quality.

Before our tutor Remo Pedreschi introduced Tyler, Alastair and myself to Eladio Dieste, we had never heard of  him or seen a photo of his work. A month on and he has become a new hero. He was a builder, architect and engineer and constructed some incredible brick structures that demonstrate the wonderous possibilities of mastering a material and using its inherent characteristics to express surface continuity, the detail of joints and structural efficiency. He became a specialist of his chosen medium through the process of refined construction, analysis and varied, improved repetition to create and appreciate buildings that display the value of what precision really means.

Eladio Dieste's Church of Atlantida during construction, Uraguay 1961

‘Today we seem to give more thought to the drawings than to the work itself…I beleive the essential thing is the work, not the plans. And if the plans prove unable to help us express something that we consider valid, this is no reason to abandon our idea.’ (Dieste)

Dieste proved that true expression comes from the act of building and constructing. The limitations of the drawing board, used to create a graphic representation of an imagined building, constrains the necessary knowledge of a material and its capabilities. Knowledge that is only acquired and attained by working with the material to understand its characteristics, properties and behaviour, with the ambition to efficiently ‘…resist through form’ in elegant and often a surprising manner.

Our fabric formed wall and final piece proved to us that Dieste was right. Never since the start of my architectural education have I produced a piece of work without using a drawing board. It speaks volumes that in 6 weeks at Edinburgh my drawing board has been accumulating dust and only used as a make-shift book shelf, totally uninvolved in the design process, whilst a team of us have produced the most personal and rewarding work of our studies so far.

”We are always faced with the limits of what we could calculate…Time consuming, uncertain processes were replaced by efficient rapid analysis.’ (Dieste)

Analysis of the first prototype column

We learnt to obey the accumulated knowledge discovered through the analysis of our previous structures. As Dieste describes ‘it will only be the power of the imagination, the ability to “see” the work through its various stages, that will be our guarantee of viability and efficiency’. This in turn would guide us to ‘a necessary precision’ for the final piece.

Analysis of the prototype wall. Determining the angles of the legs, voids and where creases occurred in the fabric. Assessing the weaker areas of the structure and finding a rule that would inform the production of the next piece of work.

We were reassured in the validity of our design process used for formwork of the wall and our final piece. We devised a set of rules that would maximise the flow and exploit the properties of a wet concrete mix. The design of each prototype was only ever sketched as an idea – the final design was only ever finalised when we were happy with the chalk lines marked out on the fabric and sewn the voids closed. Obeying the rules and making amendments where necessary to arrive at a satisfactory template was integral to the planning process.

Rules for fabric formed concrete design

It would have been impossible to have drawn an accurate plan, section and elevation of the cast concrete until we had designed and sewn the formwork and even then the exact expansion and compression of the fabric in different areas, that greatly affect the form, is almost impossible to determine without limitless and complicated mathematics. However, the consequences of the maths were on display through the analysis of previous work, so we used the knowledge and experience of our past experiments to calculate, anticipate and plan each part of the formwork – discussing, referring to the prototypes and planning how to pour and manage the concrete. The design process was in fact a conversation between the three of us with experience and faith in the materials we were using guiding our decisions.

A series of concept sketches were produced, to communicate an idea of articulating mass and form and establish the parameters of the frame we would be casting in and calculate the size of the fabric required.

A quick oblique sketch, shows the basic layout of the fabric in relation to the frame it would be hung from.

Designing was at 1:1. With discussions about the flow of the concrete, the position of reinforcement and the way the fabric would expand and compress in each area.

The wall design is drawn out , and the sleeve position for the columns determined.

Depicting the slenderness of t

Void detal in the mass of the wallMass reduction in the 'solid' side of the wall

Links to a fabric formed wall

Our first prototype wall, essentially several columns joined together that advance the discoveries and experience gained through the process of making the columns that proceeded it.

The link takes you to the Disruptive Technologies website, where there are several links to articles about the ongoing work and discussions in the unit.

http://fields.eca.ac.uk/disruptivetechnologies/

There are also two videos that show us casting and peeling the wall that clarify the process of hanging, filling and stripping the fabric.

Casting: http://fields.eca.ac.uk/disruptivetechnologies/?p=99

Peeling: http://fields.eca.ac.uk/disruptivetechnologies/?p=106

Mass reduction in the 'solid' side of the wall

Cotton Formed Columns

November 14, 2010

 

First prototype column cast in its formwork

Prototype Column – Discovery through doing

These last few weeks have been an incredible learning curve from the previous post – post-rationalising is important however in a process where technique evolves through production, analysis and improvement.

Our fabric formed concrete has evolved in such a way, quickly moving from the horizontally cast wall panels to familiarising ourselves with the technique of casting vertical column elements. There are only three of us in the unit and we quickly learnt that producing larger pieces requires good team work, ideas from each of us and man-hours to construct the formwork, cast effectively – and to succeed.

We analysed previous projects completed in 5 week workshops that have run over the last four years. Our intention was to take the wealth of experience and knowledge of past experiments and develop these techniques, refine them or even find a new direction to pursue. We were intrigued by a column that clamped the fabric to create voids by preventing the concrete filling certain areas. We liked the thought sewing a void in the fabric instead of using clamps. This technique had scope for further investigation.

The First prototype Column

The first prototype column is an irregular ‘Y’ shape with two voids. The central void was created using shaped MDF clamps, the other void was created by stitching the cotton along the top to create a final structure that read as a ‘y’. We quickly realised that stitching is an important technique in the production of the formwork and the decision to explore the possibilities and limitations of sewing the fabric was taken from there.

Prototype column initial sketch

The best way to design the column was to chalk the outline of the column directly on to the black cotton fabric. From the two-dimensional layout we calculated the diameter of the holes left open at the top – in order to construct the top plate from which the fabric would be hung and pulled into tension. Using a sewing machine we stitched along the lines to fix the shape into the fabric and prevent the concrete flowing into those areas.

Attaching fabric to the formwork

Rigging the base was tricky. A fabric wants to go into a cylinder, but we had prepared a square base so it crumpled up over the ledge. However, the final results are quite pleasing – there is an essence of a classical statue to the form. Constructing the top plate was straight forward using a jigsaw to cut an ellipse and a circle connected by a slit to feed the sewn fabric through. We ensured that the fabric was in tension and top of the column was level, stapling it to the top plate.

Top plate fixing before the pour

Casting and Patching

Patching during the pour

Our mix was probably not quite fluid enough and our first attempt at an arm was quite narrow resulting in aggregate getting stuck at the top and causing a frantic effort to force the aggregate into the arm and compact it sufficiently. In the process of solving this, we didn’t manage to push a steel reinforcing bar into the arm and we were wary that we hadn’t managed to compact the base of the arm well enough. A more serious problem arose, however, when we noticed that we had accidentally pierced the fabric in a couple of places with the vibrating rod. This required some emergency patchwork using excess fabric, pulling it around the arm and stapling it to the central clamp. We prevented the leak, but the evidence is still visible in the final cast – like the scars of construction visible like a bullet hole. Honesty and evidence of construction is important so Louis Kahn would be pleased.

A Greek form?

First Prototype column

Once the column had been ‘peeled’ after a few days curing, we enjoyed the results of our first column cast. The surface finish of the cotton was visible on the surface and the form was very appealing. Another noticeable and informative difference was the quality of finish between the clamped void and the seam stitched void.

The stitched seam was prominent on the surface of the concrete, where it had been rubbed into the surface of the wet cement. The are that was clamped had a rougher surface finish and a different colour, because it wasn’t possible to rub that area in contact with the cement.

The convenience, possibilities and effect created using stitching was an important discovery that we developed in all the following work.

Detail image of the stitched void, visible on the surface of the concrete

Verticle view showing the delicacy of the structure

The first column in the foreground with the next two in the background

 

The Bubble Wrap Bulge

 

Combining two of man’s favourite things!

Concrete is the world’s most used material after water on the planet and is here to stay for the considerable future. Bubble wrap is used for packaging…and for whiling away boredom by popping it!

There is a common perception that concrete is associated with the period of brutalism with monolithic structures that are austere. I quite like those qualities and have designed solid concrete facades in my previous university projects. One of my favourite buildings in London is the Barbican. The design incorporates different levels and terraces that are surrounded by the apartments and there are walkways suspended between the incredible columns and beams – massive even if they’re not elegant. But we’ve been learning to cast concrete in fabric that expresses its plastic quality to try and express elegance through material, process and form.

We discussed with Remo Pedreschi, our tutor, the results of previous workshops of which the fabric formwork technique was investigated. They produced a wall at the entrance to the school of architecture that has a series of concrete panels cast like a pattern book of textures and techniques that inspired our first casts.

Making an Imprint

 

Bubble Wrap frame

 

A special characteristic of casting in fabric is that the weave imprints onto the concrete. A bulge is expressed as the fabric is tensioned under the mass of the concrete and depending on the fabric’s elasticity the size of the bulge can be controlled. The surface can also acquire the pattern, dye and any stitching on the fabric. Surface texture is associated with shadow, light or even a change of temperature, abrasive or smooth to touch. This offers new possibilities for expressive and spatial characteristics that we shall be exploring in an architectural project towards the end of the unit.

The Bubbly results

Bubble wrap is extremely stretchy. The weight of the aggregate pulled the staples out of one side of the frame and we were unable to fill it up to the top, which made the edges very brittle. The concrete, once poured, requires rubbing to draw the smaller particles forward and remove air pockets. However, the water was unable to be released through the plastic so it took a few days to cure and when we came to ‘peel’ it the concrete was very dark. The edge condition was defined by a layer of celotape stuck around the edge of the bubble wrap. This gave a shiny flat edge in contrast to the bubbles although it was very brittle because of the lack of concrete at the edge of the frame.

 

Bubble bulging. The distinctive D shape and inpressive texture

 

The results were brilliant! Each individual bubble had made an intricate inverted imprint on the surface, even the dimples on the bubbles were expressed. What was more remarkable was the contrast between the bubbles against the plastic between them – which was incredibly smooth and shiny. The bubbles were also stretched along the side where the staples had come away from the frame, expressing the forces that had acted on the material as it sagged.

 

Detail texture. The smallest detail in the bubble wrap is expressed with the contrasting shine of the smooth surface between them.

 

 

The remains of the formwork

 

 

The colour is much lighter but the texture is still defined

 

Development – controlling the bulge.

In a second test we aimed to control the amount and area of deflection of the bubble wrap whilst developing a contrasting smooth edge condition. We layed the bubble wrap onto some tough and relatively inflexible geo-texile fabric that prevented the bubble wrap from sagging whilst still expressing the texture. We stapled a cotton fabric boarder around the edge and carefully filled the frame and worked the concrete to improve the surface finish.

 

Cutting a shape into the Geo-textile to control the area of the bubble wrap

 

 

Laying bubble wrap over the geo-textile

 

 

The bulge is controlled

 

 

Edge condition that caused a great result

 

 

A brilliant shine and edge condition with shadow of the prodtruding bubble wrap is also expressed

 

 

Another unexpected texture was the rippling of the cotton boarder and the imprint of the weave offer a supurb, crisp margin that can be replicated on a larger scale

 

 

The restrictive effect of the geo-textile is visible

 

Within a week had learnt a lot about the possibilities this technique and the basics of manipulating the bulges and textures. We made other text panels that shall be discussed in the next blog before commencing work on a minature column – which involved the exploration of stitching and sewing formwork to manipulate form.

 

Bubble wrapped concrete - a detail to be explored later.

 

Grappling with a disrupting definition.

It sounds to me, having read around the topic a little bit, that the actual definition and consequences of Disruptive Technology is still being debated.

The term is was first coined by Harvard business school professor Clayton M. Christensen in his book ‘The Innovator’s Dilemma‘ in which he separated new technology into two categories: sustaining and disruptive.

‘Sustaining technology relies on incremental improvements to an already established technology.’ Where as, ‘disruptive technology lacks refinement, often has performance problems because it is new, appeals to a limited audience, and may not yet have a proven practical application’

…but crucially, the new technology can overtake what has been established and advance products or methodologies beyond what was possible with the original product or idea.

‘Avoid comparing disruptive with established technology – the established will nearly always look better. What is critical is to measure the trajectory of performance improvement achievable in the technology against the trajectory of improvement demanded in the market.’ (Clayton and Christensen.)

Conventional improvement in the business and technological world similarly arises through the linear evolution as a product develops. The disruptive period of upheaval comes when a new product breaks through into the market. It could be a change in method of conducting business or organisation (e.g Tele Marketing), or an actual invention stemming from a scientific discovery (e.g. the development of a transistor), or just a good idea that a small number of people have developed for their own specific requirements and needs which has gradually become more popular.

This is the area of ‘lead-users’ developing their own methodologies in Disruptive Technology that we are interested in as we study our Studio Unit at the University of Edinburgh.

Two theorists: Raynor and Danneels had their definitions:

‘Disruption is a process and not an event…it might take decades for the forces to work their way through the market, but they’re always at work’

‘Disruptive Technologies tend to be associated with the replacement of incumbents by entrants’

By recognising what Disruptive Technologies can provide in the context of architecture, theorists have begun questioning if the term ‘construction industry’ narrows scope for innovation and the need for analysis about how receptive or resistant building trades are new technologies.

Can our methods change in order to improve our buildings?

This is where our new Studio Unit begins and the connection is made to the Blog title ‘Concrete Fabrication’.

 

 

Fabric Mesh

 

I and two other students at the University of Edinburgh are currently aiming to ‘disrupt’ the conventional methods of casting concrete. The traditional methods commonly use solid formwork that requires substantial labour and material with varying results and quality. We aim, under the guidance of our tutor Remo Pedreschi to explore and push the possibilities of using fabric as formwork in terms of form, texture, strength, ease of construction, quality of result, time and cost.

I intend to use this blog to publish our discoveries and discussions, with the intention of sharing information and as a method of recording the progress of the project.

Hopefully this will be an interesting process as we endeavor to disrupt this technology…