Interview with Finn Geipel and Giulia Andi, architects

Why did you choose to use concrete for this project?

We wanted to respect the historical dimension of the Arsenal Pavilion in Paris, yet we were seeking to maximize the space. That is why we chose a shell installed inside the building. The important issue was: what would this shell be built of ? We wanted a unique, monolithic material which would embrace the shape of the shell. A solution using metal was too heavy and unacceptable with respect to fire safety. Wood was too theatrical, composite material too sophisticated and too many connotations. A mineral solution was all that remained, yet concrete is a problematic material, and one which is often criticized. This created a real challenge for the use of concrete in the Arsenal Pavilion. We wanted to use concrete "in the rough", for its immediate, natural qualities. The tactility is cold, the surface reveals the depth of the structure, and the sonority is very special. Plus, it can be shaped, cast in a mold.

Why did you choose Ductal^®?

We were already familiar with fibrous concrete. We had several requirements that material performance had to meet. Ductal^® provided us with outstanding stability working with minimal thicknesses. At the start, the issue was not so much choosing a material as it was to successfully conclude the project and meet our needs. The qualities inherent in Ductal^® rapidly made it an essential component of our project.

Was using Ductal a complex task?

We were not familiar with Ductal^®. So we had to find subcontractors who were capable of matching our creativity and working with our demands. We were lucky to be able to work with Bonna Sabla (concrete precaster, ndlr) with whom we did advance work on research and applications for the use of Ductal.

Will you be using Ductal^® again on other projects?

Quite clearly we will, for it is material that we like a great deal. Its intrinsic qualities enable great architectural creativity and freedom.