Final Assignment: Throw Away Heroes

toronto-bans-plastic-bags

Aim/Goal

The aim was to recreate a plastic bag with concrete casting.

Important factors or characteristics of the plastic bag that I wanted to recreate was its lightness (weight), its creases, its smooth (often) glossy surface and of course the function as a container.

The base of this research, or experiment, derives from the assignment made in the “adaptive formwork” by the concrete guru’s; Daniel Ellis Karlsson, Jakob Lif and myself, but is here a bit more explored.

DSC_1203[1]

 

Method

The method requires: 3(!) plastic bags, sand and concrete.

The first (inner) bag is the create the void, therefore it is filled with sand to hold the pressure. It also gives the casts inside its texture.

The second (middle) bag is to contain the concrete mix and give the outer texture.

The third (outer) bag is to “suspend gravity” by giving support to the cast, it is also filled with sand. This is the least necessary bag, but without it the middle bag would want to expand to its fullest, making the cast balloon-like.

Comments

The concrete should be able to recreate the texture of the plastic bag and fill all hollows while still retaining its stability.

I used a quite standardized and common plastic bag in the series of casting: the Toppits 2 l freezer bag. According to the producer it’s very durable, easy to fill because of the flat bottom and wide opening, and also hygienic. This together with the thin plastic made it the perfect choice.

bild

It gives a very cheap look to the cast, because the plastic lacks rigidness it creases a lot against the supporting sand. A thicker, more rigid, plastic would give a classier look.

A08AF2FA-E86B-4FBE-BE2A-E4618877FF96

Top: plastic foil

Middle: freezer bag

Bottom: plastic bag (big format; approx. 75×75 cm)

Casted against sand (<4 mm)

 

1 part Cement

0,5 part Water

 

I also tried with adding some pigment to distance the final product from the concrete feeling and bring it further to the plastic aesthetic.

 

 

The Story

WP_20170428_10_15_34_Pro

1 part Concrete

0,5 part Water

0,01 part Superplasticizer

After trying to recreate that cast I found that that method gave a very thick and heavy cast, probably due to the amount and size of the aggregate required.

 

WP_20170428_10_14_50_Pro

1 part Concrete

0,5 part Water

To overcome this problem I instead tried to cast without aggregate. The obvious solution! This required a change in technique. The concrete could no longer be added in the end by pouring from the top, but had to be built in the mold. I built up the cast layer by layer, with sand and cement.

The result was more in the spirit of a plastic bag than the first try, but the lack of aggregate and the very fluid concrete mix led to that much of the mix built up in the bottom and the walls only became (too) thin shells at best. This could either be fixed by a more solid mix or/and by adding some aggregate that would give the construction necessary thickness.

 

WP_20170428_10_16_14_Pro

1 part Concrete

1 part Aggregate (sand)

0,5 part Water

So the third try was with a more sturdy mix, that wouldn’t completely give into gravity and settle in the bottom. This was the most successful attempt. Recreating the lightness, but still having some stability, evenly spread thickness, full of wonderful plastic bag creases!

WP_20170428_10_34_41_Pro

WP_20170428_10_35_32_Pro

1 part Concrete

1 part Aggregate (gravel (>4 mm) (first picture) or  sand (<4 m) (second pic.))

0,5 part Water

1 % red pigment for the gravel cast and 0,5 % for the gravel.

 

To further experiment on this method I made two more casts; one with sand as aggregate and on with gravel. I also let the supporting material of the two casts be the reverse from the aggregate. So the mix with the sand as aggregate had gravel as supporting material.

The gravel mix didn’t blend well, leaving pieces of rocks in a cement slurry, which gave to cast a very varying thickness of goods. Breaking in some parts, being too thick in some. This I think could be helped by lowering the water content.

The sand mix came out well, the only whole cast. The walls are a bit too thick to go as a plastic bag, but this could easily be helped by adding less of the concrete mix into the cast. Even though there still is to explore: were the breaking point between “thin and broken” and “thin enough and whole” is.

 

10/10, would cast again.

Advertisements

Final assignment – free form in aggregate

We set out to make an organic free form shape cast only in different sizes of aggregate.

IMG_7181

The result of the first test of aggregate and slurry mix. The straws helped the cement mix to go down in the aggregate and the slurry mix seamed to work so we went up in size for the final cast.

IMG_7900

We used three different sizes of aggregate, very small which we sieved, middle size and quite large pieces for where we wanted the cement mix to go down.

IMG_7904IMG_7906IMG_7907IMG_7908IMG_7909IMG_7911IMG_7912IMG_7913

We poured the cement mix in steps to make sure that it would go down in the aggregate, and built the shape in many layers.

We used the slurry mix we tested in the first experiment:

750 g cement
300 g water
15 g super plasticizer

IMG_7247IMG_7250IMG_7255

The end result.
A piece fell of in the process of removing the cast from the bucket, we could have reinforced the shape with for example steel wire, or greased the bucket before we cast.
Otherwise the shape we got was what we set out do make. The different aggregate made it possible to make voids and the shape was quite easily controlled.

How to go forward.
The method of casting in only different aggregate is good since there is not much waste material, and you don’t need that much cement since it is such a large portion of aggregate.

Final work

Smocking by Erika Vegerfors

18197194_10154479138844080_2106805961_n

18191225_10154479149724080_1260902055_n

18191405_10154479138709080_1543660077_n

18197264_10154479138759080_715684444_n

18216958_10154479133469080_867222018_n

18191050_10154479133449080_555304616_n

18217613_10154479348389080_1917644918_n

Work in progress…

Final assignment.

In the final task, I chose to develop the smocking textile method that I tested earlier. I have now constructed a pattern that “grows”. The idea is that the pattern should extend across several tiles. In the end result, I expect to get three different sizes of tiles, 200×200 mm, 200×150 mm and 150x 350mm which together cover a surface of 350×350 mm and one pattern.

The difficulty in this task was to design the pattern and calculate fabric usage for the 350×350 mm surface due the textile is pulled together by the smocking.

I made the mold in plywood and I mounted the textile with staples on the wood skeleton.

The casting went well at first… But, at three o’clock in the night I forgot to pour in lime stone in the last casting of three. I see this now as a study and can compare how the concrete tiles comes out with or without lime stone in the concrete mix.

The entire process of constructing patterns, to sew, make a wooden mold, cast and finally piling off the fabric stuck in the concrete, makes the process very time-consuming, but very fun.

What I present here on the blog today is a work in progress…

/Erika

 

 

 

final assignment-volcano

In the final assignment, I want to continue with the fluid form, cause I want to develop the uncertainty and changeability of concrete.

At first, I did a small test to find the right supporting material. Pouring the same concrete onto a matte plastic film and a soft plastic bag. Although I know it’s hard to control the shape of fluid concrete, I want to see if it can be affected by material and has a predictable shape.

From the results, we can see too soft material increases the uncertainty of shape and too matte material prevent the flowing of concrete. So at last I chose the harder plastic film and made a pyramid to let the concrete flow down easily.20170426_143100

I simulated the shape of volcano with different layers (different water in every layer).

Firstly I poured down the most fluid concrete (0.200kg) onto the pyramid as the first layer. The concrete went far. After 1 hour, I poured down the less fluid concrete (0.150kg). However, the first layer didn’t dry very well and mixed with the second one. Then I waited another 3 hours and poured down the third concrete (0.100kg). This time it looked with obvious border. Finally I poured down the last concrete (0.050kg) after almost 20 hours.20170428_104057

20170426_14574320170426_15343020170426_18161320170427_155155

As a result, I think the final casting looks like a volcano — every layer has an obvious border (except the second one). They come out in different time with different viscosities. We can feel the uncertainty and changeability of fluid concrete. For the future development, I consider we don’t need to do the casting once, but do it by steps to control the whole process.

Final Assignment: Catenary vault

For my final project, I wanted to work with textiles and gravity, inspired by Gaudi’s studies of self-supporting pillars and vaults. I would like to learn more about catenary – the physical term for the idealized curve, and how it can be used for making vaults. I believe that it now is possible to again use curved vaults in architecture, which have not been so popular for quite some time.

I wanted to make a self-supporting vault, casted upside down. The idea was that by hanging the fabric mould – the concrete would move into the most ideal curve for the vault, and as such be self-supporting. The process is described below:process.jpg

For my prototype I simple stapled two pieces of stretchy jersey fabric together and let them hang, filled with concrete. It seemed to work very well, but the casting had not fully dried in the right picture, so the fabric was not removed.

For the final product a template was made and the jersey fabric cut accordingly. The mould was hanged from each corner of the box and then filled with concrete. By now, I realized that the final product would not be rounded, rather more rectangular. The concrete mixture followed the give recipe for fabric casting, but extra water was added to make the mixture more fluid to fit into the mould.

After three days, the casting was removed from the box. When turned upside-down the casting could luckily support itself. However, it seems as if the casting has broken in the top – where the strain on the mould was the highest and the hole on top was the biggest. As such, the casting is probably in two pieces. Furthermore, it seems as if the concrete has not yet dried as a thin layer of concrete follows when pulling off the fabric. Perhaps in a few days the fabric can be more easily removed.

final product finished

The final product looks good (although with the fabric still on) and is self-supporting. The breaking is most likely due to the fabric mould that probably was too thin in the lowest-hanging parts. The size of the hole on top also plays a big part in the breakage. Had the hole been smaller the breakage might not have occurred. Also – the two pieces of fabric should probably not have been exactly the same size. Rather, the lowest hanging piece should have been larger and as such allow for more concrete further down – strengthening the casting. Perhaps the lower hanging textile could have been a stretchy jersey and the top fabric a more sturdy woven fabric.

Summary:
Prototype:
casting worked well – had not dried when casting finished product

Finished casting:
Fabric mould had too big of a hole – should be decreased
Mixture had extra water to increase fluidity

Finished casting has not dried – fabric cannot be removed yet
Finished casting has probably broken in two pieces
Structure is self-supporting (yay!)

Final Assignment, balloon blobs

img_2953.jpg

I wanted to investigate in how concrete would act when being restrained by a flexible material (a balloon). By adding several balloons together inside a rigid form, they would also take shape by each other and the external shape. Like a specific brick-system, where they only can be placed in one specific way but then be perfect.

In the first stage i investigated how to cast into balloons and how the result would be. By using a funnel and making a more liquid mix (I used the mix of the flexible formwork but added water), the concrete easily flew into the balloons. By adding an extra tension to the shapes, with the string, the shapes became more interesting!

Before casting into the balloons, the rubber had to be stretched out, to maximise the amount that fits into them. So I simply blew them up for a few minutes before casting. I then started to fill the external wooden frame with the concrete filled ballons. To some I added rubberbands, to others I did nothing, and a few of the balloons where also heart-shaped which by themselves created interesting shapes!

When the box was filled and dried, this was how they look, the tob being more 3dimentional and the bottom more restricted:

And when stripping them of the ballons and then returning them to the shape, this is how they looked (because a lot of water was added, it created a layer on top where only water and a little bit of sand and concrete gathered, and cracked):

FullSizeRender 5

final assignment: contrast bowl

finale

For my final assignment I wanted to do something which could have some function afterwards. So I decided to make an easy form which then can be used as a small bowl to store stuff.

My aim was to create an interesting form with a high contrast between inside and outside.

I also aimed to use as different techniques we learned during this seminar, which included fabric formwork and formless cast for this project.

On the first try I built a frame and attached fabric to it, to pour concrete inside.
This concave form I used as a negativ for the bowl. I covered it with palstic to keep water from it and attached fabric again, so the texture would be visible inside of the bowl.

For the outside I wanted – in contrast to the inside – have a texture as ruff as possible.
So I decided to take concrete with a high amount of sand. I then added more water to make it liquid enough to proceed over the form by itself. I tried to add the concrete step by step to create layers.

It was quite hard to strip the formwork as it was both concrete, that´s why part if it broke.

For the second attempt I decided to higher the contrast between inside and outside. Especially the inside I wanted to have finer and more detailed. I went for a volume of two geometrics, a circle and a square, joined by a plastic foil. From previos tests I knew that the foil would create a shiny flat surface, but as it is soft, it also acts similar to fabric in its form.