From 25 November 2021 to 27 February 2022, the Pavillon de l’Arsenal will host the TerraFibra exhibition, which highlights these bio-based materials, both ancestral and future-proof.
Rammed soil, mud, adobe, flasks, straw, hemp, bamboo, pipes … Without provoking in this very concrete country, which is France, but by demonstrating pedagogy, “TerraFibra architectures” aims to highlight the existence of other techniques and materials to construct buildings in a more sustainable and economical way.
Located on the top floor of the Pavillon de l’Arsenal in Paris, the exhibition unveils the 40 finalist buildings for the first world prize for modern architecture in raw soil and / or plant fibers through photographs, technical drawings and scale 1 prototypes that can be touched to discover the organic qualities of these materials.
The capital of Paris in bio-based?
The discovery of those nominated for this competition allows them to travel around the world (India, China, Thailand, Spain, Benin …), which for the plant fiber section passes through … Greater Paris. No less than four Ile-de-France projects were therefore selected. Starting with the filling, in 2021, of the hemp-lime walls for a nine-storey residence in Boulogne-Billancourt (Hauts-de-Seine), which is the first in France or even in Europe. The building’s reinforced concrete skeleton is thus five times less heavy than concrete walls with added insulation. If the chènevotte used here comes from the Aube, the curator of the exhibition Dominique Gauzin-Müller states that “local sectors have developed in the Seine-et-Marne and in the Gâtinais”.
Another finalist achievement in Ile-de-France: the 2016 thermal renovation of an old building in the 14th.e arrondissement in Paris by renovation of the facades of the courtyard and insulation from the outside in projected lime-hemp. “This technique reduced heat loss by more than 50%, while at the same time rendering the original decoration of the facade identical. The very good weight-performance ratio made it possible to balance the budget because it avoided structural restorations, ”explained Dominique Gauzin-Müller.
La Ferme du rail, in the 19th arrondissement of Paris, the first implementation in 2019 of the “Réinventer Paris” 1 call for projects, offers straw insulation for two wooden structures that frame the kitchen garden. Finally, the leisure center Jacques Chirac, built in 2020 in Rosny-sous-Bois (Seine-Saint-Denis), renews walls in load-bearing straw bales on two levels with lime-sand plaster on the outside and earth plaster inside. .
The cast earth, the concrete of the future
If there are no constructions in the Ile-de-France region in the part of the exhibition devoted to building techniques in raw soil, large-scale realization of buildings in this material in the Paris region is by no means impossible according to the Commissioner of the ‘exposure. Dominique Gauzin-Müller then prefers the technique of soil poured in formwork as cement concrete. However, for bonding to take place, it is still necessary to use between 3% and 5% cement. “Raised soil is a relatively new technique. Several research centers are working with additives that make it possible to no longer need cement at all. But a solution had to be found quickly. From there, any company that knows how to make cement concrete will know, how to make clay concrete. It’s a way to quickly massify the construction in raw soil. Another advantage of this technique is that soil is used on site. “
TerraFibra architectures, from 25 November 2021 to 27 February 2022 at the Pavillon de l’Arsenal, 21 bd Morland, Paris 4th, pavilion-arsenal.com.