The First Pour

My first fabric formwork pour was a success! Using three assembled pieces, I was able to create a concrete that molded to the fabric between support points. The assembly had three pieces-a base on which the support points were glued, a lower frame over which the fabric was stretched tightly and a third frame into which I poured the concrete. To make sure the concrete wouldn't adhere to the fabric I applied several layers of spray shellac as well as petroleum jelly to the fabric. On the next pour I might not apply so much petroleum as it did affect the surface texture even if it made it very easy to pull the concrete away from the fabric. My next step is to make an inverse mold of this mold but stretching the fabric over the already poured concrete and pouring new concrete over that. Below are some pictures of the process. The first is the three frames unassmebled, the second the assembled frames with the concrete poured, and the last the finished product.

Forming Flexibly

My original interest in concrete formwork led me to find the curious idea of fabric formwork, which is being developed as an efficient and “green” alternative to traditional formwork options. Developed primarily by an entity known as CAST (The Center for Architectural Structures and Technology) at the University of Manitoba, fabric, primarily geotextiles commonly used in road construction, is being used as a formwork that gives architectural beams and columns a more efficient shape, cutting down on the amount of material used than when creating more traditional-shaped pieces. The results are beams that look almost exactly like a moment diagram of the concrete-deeper at locations with more stress or strain, slimmer at areas under little strain. Not only is the shape the most efficient use of the material, but the shape itself is elegant and appears natural due to its basis in mathematics and physics. To the human eye, it just makes sense.

Fabric formwork also gives the finished concrete a level of strength not given by other formwork due to the filtering that occurs through the fabric. The porosity of the fabric allows air bubbles and extra mix water to filter through the formwork membrane. The formwork itself is also very lightweight, inexpensive, and, due to its flexibility, reusable for multiple castings.

Aside from the efficiencies that can be produced in structural concrete members, fabric concrete also provides flexibility in design for architects, allowing them to create a variety of forms otherwise impossible with more orthogonal formwork types. The shapes created by fabric are tensile geometries, something that would be hard to obtain in concrete, a naturally compressive material.

One of the main architects exploring the possibilities of fabric formwork is Kenzo Unno, who uses fabric formwork to obtain both an efficient use of material and certain aesthetic desires in his work. In his research, Kenzo Unno was able to create a “zero waste” wall assembly into which the concrete is poured and the only piece that is then removed is the fabric formwork, which can then be reused for another casting or as an earth stabilizer. A diagram of the wall assembly can be seen at the right. The linear wood pieces on the exterior become battens onto which the exterior cladding is applied. These wall assembly pieces can easily be constructed off-site, and then dropped into place on the construction site.

Aesthetically, Kenzo Unno has done a lot of cast-in-place walls in fabric formwork, giving walls a soft, pillow-like surface, and again reducing the amount of material wasted during construction. His cast-in-place walls have come in two forms, one known as the frame method, the other as the quilt-point method. The frame method uses a series of vertical restraints in between which the fabric is stretched and the concrete poured. The quilt-point method uses a series of ties in the walls between which the fabric is stretched and the concrete poured. The concrete is vibrated externally by poking the wet concrete contained by the fabric with a stick and, as in the case of the quilt-point method, the fabric being stretched by the concrete forms into its natural tension geometries, allowing it to be entirely self-sufficient structurally.

Fabric formwork has also been used to create precast concrete panels in a variety of forms. The method for producing these forms is simple-first a rectangular frame of the dimensions of the final panel is laid down inside of which intermediate supports are placed (these supports will retain the fabric at these points and the fabric will in turn bow between them). Next, a pre-tensioned fabric membrane is placed over this frame, on top of which an upper frame that will contain the wet concrete is placed. This frame will determine the edge thickness of the panel and inside of it any reinforcement can be placed. When wet concrete is poured into this assembly, it causes the fabric to deflect downward creating three-dimensional tension curves between the designated support points of the base frame. The castings created from this method can then in turn be used to create inverse castings by pouring a new casting along its surface on top of a layer of fabric.

The implications that this research has on the future of concrete as a building material are huge. Not only is it efficient in how it uses materials in construction and creates a strong product through the filtering process, but it provides an aesthetic to concrete previously unavailable. I like that the fabric formwork uses the properties of wet concrete to create its form. Instead of trying to contain the wet concrete, it works with what it naturally wants to do unlike many other types of formwork, allowing what is seen as a “difficult” property of the material to become its driving force. The next step will be to test some of these processes myself-specifically the precast panel construction method-on a smaller scale.

What aspects of this research will translate into the warming hut is yet to be seen. I definitely like the idea that using this formwork will allow for less waste as our hut is located at the top of a very steep mountain side and so to have a lot of waste due to construction would be very inefficient indeed. I also think the efficiently shaped beams that give a very natural form to the architecture is something I think I’d like to apply to the warming hut. Let’s see what the castings help me discover.

References:

"CAST :: Fabric Formwork." University of Manitoba. Web. 23 Jan. 2011. http://www.umanitboa.ca/cast_building/research/fabric_formwork/index.html

Miller, Anne. "Concrete Dreams." Canadian Architect (2008): 71-73. Print.

West, Mark. Kenzo Unno Fabric Formed Walls. PDF.

West, Mark. Prestressed Fabric Formworks For Precast Concrete Panels. Centre for Architectural Structures and Technology. PDF.

West, Mark. "True to Form." Canadian Architect: 54-56. Print.

Measured Object Excercise

A throwback to 1st year, my measured object. I really enjoyed this exercise as it was nice to hand draw something for a change.

The Warming Hut

Starting off studio with a small design problem-a warming hut for skiers that incorporates the complexity of a steeply sloped site and the complexities present when designing with concrete. When looking up precedents, one theme came through pretty strongly-the idea of centrality. Most warming huts are organized around the stove or fire, which makes for an efficient transfer of heat to many people but also provides the perfect place for people to gather and talk.


I see the warming hut being a very welcoming place on the side of this large, frosted mountain. In a landscape that can seem pretty forbidding to humans, the warming hut should provide a sense of comfort just upon sight. It is why I chose to nestle my warming hut in a nook of sorts of the mountain-a place where the land almost folds back in on itself, which would allow the warming hut to be almost embraced by the mountain. Most warming huts do this when they're constructed of materials that inherently provide that sense of warmth, like wood, however, with a concrete structure, this could prove to be a challenge. To me, concrete has always seemed to be a fairly cold material, institutional almost, so the challenge will be to make concrete friendly and inviting. Almost the exact opposite of this idea is the image seen here-what seems to be almost an ice fortress on the mountain that looks like something from out of the Lord of the Rings. While uninviting, it does have its place on the mountain and it fits in almost perfectly with the bulky snow peaks and tall evergreens surrounding it.

ESPANA!!!

Two Day Trips and The Grand Finale

Our first day trip was to Igualada, where we visited a cemetery tucked away among industrial warehouses on the cliff of a large gorge. It was a very different style of cemetery with rows of tombs set into the cliff-side. Here was truely a place where people could visit their loved ones in a peaceful setting. On our return to Barcelona that day, we visited a public library that also included outdoor public space behind it. The library itself was really nice-I could see myself bringing work there, plus it was right next door to an excellent coffeeshop.
Our next day trip was to Granada where the purpose was less to see specific architecture than to wander around the small town. A long medieval wall runs along the top of a large hill overlooking the town and the mountains behind it and from there we could watch planes flying in and lightning striking the mountain tops.
Our last day in Barcelona we visited the Jean Nouvel shopping center which is very well integrated into the city fabric and looks a lot like a skyscraper turned on its side with its many setbacks along the street. From there we visited the School of Architecture at the university where those of us staying for the workshop in Barcelona will be spending two weeks. Also there was a fantastic architecture library and bookstore-both great places to spend lots of time, as I'm sure I will.
Lastly, we went to an apartment complex that really redefines living in an apartment building, for each apartment has either windows or patios both looking inward towards the interior courtyards and outwards at the city. The corridors leading to the apartments are such that you are forced to meet your neighbors and interact with both the people around you and the city. The whole complex acts as its own small neighborhood with movie screenings and outdoor pools on the roof. The architect's offices were right next door in these fantastic converted silos that looked like something out of jurassic park.
We were supposed to take the funicular up to the top of Tibidabo, the highest point in the city, but did not have time. (I did make it up there the next day and the views were amazing as you can see...)
That night we all went out to an excellent tapas dinner together where we presented our professors (who love maps) with a map of Spain/Portugal on which we had written and drawn all the random and hilarious thing that had happened in each city. It was a great night for reminiscing on all that had happend on our month across Spain and Portugal.

Chicken Heads, Fire Running, and Floating Planes

We started the day visiting a couple of Barcelona's famous outdoor markets where every variety of fruit, vegetable, and meat is sold. We had a fairly curious task here-to find the strangest thing we could buy for under one euro. We found some pretty strange things including chicken heads, rabbit heads and even some animal's brain that came in its very own brain box. If you weren't grossed out enough, here's a picture...
Aside from these oddities, the markets had so much that was delicious including lots of fresh and dried fruit-even dried kiwis and raspberries which i had to try, naturally.
We also paid a visit to the Barcelona Center for Architecture, which had an exhibit on state financed buildings as well as a fantastic architecture bookstore-always dangerous. Continuing our walk around the old city, we came upon an old Catalan tradition of fire running in which kids get to dress up like devils and run around with a firecracker on a pitchfork. Even the littlest kids were allowed to participate and didn't seem the least bit scared. I did creepily take a video of one of them...
After lunch, we walked to see Nouvel's iconic skyscraper that is as of now the tallest building on the Barcelona skyline and lights up in an array of colors at night. We continued down Diagonal street, so called because it moves diagonally through the city grid, go figure, and stopped at a park by Nouvel and one by Miralles both of which play with ways to make surfaces or planes that divide up the park. One even had the planters hanging as if they were the tree canopy.
We ended the day at a bar watching the disappointing results of the U.S. versus Ghana game. Oh well, maybe next time...
The next day we met at Plaza Espana and deaded to Mies mecca-the Barcelona Pavillion. Created for the -29 World's Expo, the Pavillion is a temporary structure that was rebuilt in the 80's and consists of a series of planes that seem to just float, as if they were in movement and were just captured for a moment in this position. The richness of the materials also make the pavillion somewhat of a jewel-different types of marble, pristine glass and, of course, travertine floors.
Right across the street was the Barcelona Cixa Forum housd in a converted warhouse. The roof of the building reminded me of the roof of Case Mila-with a series of interconnected walkways/roof surfaces, creating a small city on top of the city. There we found a plyaful photography exhibition by Jacques Lartigue of people mid-jump, in flight, and included a series of 3D imges.
We broke for lunch at the top of Montjuif which had fantastic views of the city and then continued up the mountain to the Botanical Gardens and site of the '92 Olympics. The Gardens were very pretty with plants from all over the world and, again, excellent views of the city. After taking the funicular down the mountain, we found another to climb-we were headed for Parc Gruell, the parc designed by Gaudi. This park was massive and had so much Gaudi in it, it could have almost been a Gaudi amusement park.
We ended the day in the Gracia neighborhood home to actual locals and a Lebanese bar/restaurant where Argentina was overwhelmingly favored to win in their game against Mexico, which they did.