A conference on the use of fabric formwork for architectural structures drew interest from around the world.
By Sharon Roe
Whether you are drawn to the sinewy, sensuous concrete forms shaped by spandex or to the simplicity, efficiency, and flexibility of the geotextile-formwork, this conference was a feast for the eyes and food for the brain. Presenters came from around the world and shared — for the first time as a collective — their experiences with fabric-formed architectural structures.
Fabric-formed concrete uses flexible, permeable textile membranes (geotextile, cotton, spandex) in place of rigid formwork for concrete construction. Excess water and trapped air are allowed to escape through the membrane while the cement paste is retained. This technology eliminates most of the problems encountered in a traditional pour. Also, with the fabric and the minimal supports required to hold the fabric in place, the fluid concrete is free to find balance with the form as the form conforms to the slurry.
Responding to dreamlike landscapes of his automatic drawings and the availability of an old T-shirt, architect Mark West produced his first fabric-formed concrete. This experience revealed a fuzzy concrete surface — one that you just had to touch. Beginning from this poetic act, he continued his experiments. Whereas Louis Kahn asked the brick what it wanted to be, West asked this of concrete. From cotton to spandex, these experiments produced sensual, skin-like, textures on the surface of concrete forms that had the anthropomorphic qualities of bound bodices and bulging bellies.
Although the elements are beautiful and seductive, most of the builders who are using fabric forms began with a need for practicality. With an eye to the construction site, attention turned to geotextiles. Not only are these durable fabrics already a part of the contractor’s supplies, they function similarly to all other fabrics that have been studied in forming concrete.
Tokyo architect Kenzo Unno developed his construction system in response to the 1995 Kobe earthquake. His requirements were that it had to be earthquake resistant, inexpensive, and easier to build than wood construction. David South, co-founder of Monolithic Constructors Inc. and the Monolithic Domes Institute, uses inflatable fabric forms that are sprayed with concrete to form thin-shelled domes. His system allows for both very large and very small construction, including hand-built housing in developing countries. Sandy Lawton, of Arro-Design, Waitsfield, Vermont, was commissioned to build on a delicate and difficult site. Using fabric Fast-Forms developed by Fab-Form Industries, they were able to drop in the fabric tubes and form five, 9m columns—each column completed in a single pour. Those five columns created a minimal footprint for the remaining construction.
Yet, in spite of all the positives, the construction market has been slow to adopt this new (no matter how simple) technology. Although it seems almost intuitive that these are excellent systems, there are still many questions and uncertainties. Because the forms have complex curves, the engineering calculations for structural loads are atypical. Researchers such as Arno Pronk, Eindhoven University of Technology, Holland, have begun to understand the structural capabilities and improved strengths possible with the fabric form. Pronk recognized the complicated curving structures draped by fabric were similar to clothing so he borrowed analytical software from the fashion industry and successfully modeled and analyzed these form-active structures.
In the end, it all came back to the T-shirt. Although people had worked independently, the integrity of the construction method had made its way around the world, through artist studios, architecture classrooms, developing countries, post-earthquake zones, research labs, and ended up at this conference — the best one I’ve attended in a decade.
The First International Conference: Fabric Formwork Conference for Architectural Structures, held May 16–18, 2008, was organized by Mark West and the group from C.A.S.T. (The Centre for Architectural Structures and Technology), University of Manitoba, Winnipeg, Manitoba, Canada. For more information on the conference and the speakers: www.fabricforming.org/news_ff_conference.html.