Bâtiment administratif du centre bus RATP – Thiais

The building concentrates lots of specificities and lots of representatives. The centre accommodates 300 buses. 800 bus drivers forward trough the building every day, plus the administrative staffs which manages the centre. It’s a flux building. The plan has been in evolution during all the studies, the work and is still “moving”. So there is no pre-determined structural or functional screen on the building. Aside the administrative building, the program included the realization of a new checkpoint of the centre and a bikes shelter. It’s located in Ile de France, in the south of Paris in the 9-4 department. It’s an industrial context, characterised by a succession of boxes, at best basic. In this chaotic landscape, there is not much to say. Solely can we point out one federating element : the mineral ground – a mix of asphalt and concrete…
We reduced the site to a bus park, a vast monolithic concrete slab, uniformed territory composed of one sole material. The building starts with the deformation of the ground, the distortion of the existing concrete slab, and continues it with an apparently similar material Ductal ®, still concrete but a dazzling sheet of concrete, which responds to very sophisticated demands: informality of the structure, constant evolution of the plans, dematerialization, precision, density, homogeneity of aspect according to the mould designed. It ensures a continuity of the ground from the road, to the skin of the façades, the suspended ceilings and the terrace rooftop without any rupture. This possible dematerialisation comforts the approach of sustainable construction objectives; the precision contributes to the conception of the facades as a skin with an exterior isolation, homogeneity of aspect allowing carrying out any specific pattern. Combined with the structural qualities of the material, the building has neither a beginning nor an end. It is a continuity of a surface of which we can, depending on what you aim at, not control the limits. It is an inflection of a slab which spreads on the whole site.
The building appears like a monolith with rounded edges, polished somehow. Characterized by a dense square plan (35m x 35m) developed on 2 levels, it presents itself as the continuity of the banal coating of the roads, like a piece stamped from distorting the existing concrete surface of the Bus Center. The Ductal ® is used here as a morphing to cover the carcass of a composite program. The result is a dense building, inert, deaf, and enigmatic as “the hull of a Russian submarine in the waters of Murmansk”. The building is deformed by stamping its context – uniformity between the building and its support to a point of confusion. This crust that covers the evolution area of the buses is distorted, modeled to cover the administrative center. The “windows” are cut with a cutter blade : surgical incisions generating volumes in negative which reveal colored mirrors under the thin crust of concrete. The texture games are facilitated by the flexibility of the material and its ability to be molded with precision. The quality of finish and rigor of Ductal ® contribute to ensuring this concrete skin, accurate, continuous, perfect connections. The skin : 3 cm thick displays a single texture of dots in relief like a game of « LEGO »: 24 mm diameter  x 7 mm high, distant  of 12 mm. The concrete hull is cut out with a cutter putting at sharp, revealing cavities of reflective and coloured glass under the concrete crust. Treated with silver mirror dots, chromatics of the glass products are inspired by the tinted curtain wall frontages of the office buildings which border the main road.