Architect

Architect Enri Chabal exploits the innovative possibilities Ductal® provides to create light, complex forms which display outstanding strength. One example is the sun shades which he designed for the university library on the Doua scientific campus in Lyon.

Why did you choose Ductal® to create the sun shades at the university library on the Doua campus ?

Enri Chabal – I was looking for a material which most closely resembled the concrete used to build this building in the 1960’s. I also sought overall harmony and building materials that would age in a similar fashion. We also had to solve the constraints inherent in installing sun shade segments on this concrete façade. Lastly I wanted to create elements which were extremely thin, between 3 and 4 centimeters thick, yet with substantial span, between 1.7 and 2 meters. Graceful elements which were capable of withstanding significant loads such as heavy snowfall. Ductal® met every one of these demands.


Was it the ideal material for this type of creation ?
It is indeed totally unique, and displays several mechanical and esthetic qualities. It provides the architect with nearly unlimited potential to create complex, even extreme shapes that are also very light. It’s a bit like working with modeling clay. You can do just about anything with Ductal®, it facilitates architectural creativity and enables you to reach new heights. It is ideal for use in small areas, on facings, decoration and other uses, despite a few technical constraints.

Such as ?
Ductal® is a highly technical material whose use requires total technological control. Its ability to replicate mold textures is such that if the mold is perfect, the concrete surface can appear as sleek as metal or plastic. In this case, it is less appealing for an architect like me, for I seek, above all, a somewhat mineral texture. For the Doua library, I had to explicitly ask the manufacturer to leave a few “defects” (blisters) so as to retain the appearance of concrete. Yet, I also used the luminosity and the reflection to turn the sun shades into “shelves of light” able to reflect the sun’s radiation onto the suspended ceiling which diffused the light inside the building.

What, in your opinion, is the best market for Ductal® ?
The market for the renovation of old buildings, at any rate due to the purely architectural possibilities it provides, for with Ductal® you can redesign the façades of the buildings you renovate.

Architect Rudy Ricciotti was one of the first to utilize the technical and artistic potential provided by Ductal® designing a long-span pedestrian bridge the “Footbridge of Peace in Seoul”.Now, he plans to put the material’s potential to work again, in the grids on the façades of the future Museum of European and Mediterranean Civilizations in Marseille.

When and how did you discover Ductal®?

Rudy Ricciotti - I actually discovered Ductal® several years ago and was immediately struck by the intelligence of the material, recognizing its true vocation. Innovation always comes from scientific transversally – and here, we are dealing with chemistry, the physics of solids and technology, the adventure is fascinating.

What construction sites have you used it on?
I used this material in Korea, for footbridge in Seoul, (an arch that spans the river). Currently, we are using it in the design phase for the National Museum of European and Mediterranean Civilizations in Marseille, and for a private home.

Which of Ductal®’s qualities do you consider to be the most important and the most useful for an architect?
I think true invention could be based on the use of this material. From the architect’s point of view, the strong compressive values challenge the modernists’ convictions. The importance of compression will return to center stage in the structural designs, but also involve a break with the modern movement and the same will be true of bending. As the material has extremely low porosity, it will be a source of surprises; bringing to mind the tightness that is one consequence and should strengthen the search for a new return to structuralism and a quest for the beauty of concrete.

Architects Finn Geipel and Giulia Andi used Ductal® to build a thin mineral shell inside the Arsenal Pavilion in Paris.This Ductal® display houses the permanent exhibition on the history of Paris.

Why did you choose to use concrete for this project ?
Finn Geipel – 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.