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