Ductal®, a tailor-made solution for this haute couture project
A masterpiece of architectural design, the Fondation Louis Vuitton has met a host of technological challenges that have necessitated six years of work, involving some 120 architects and engineers. The Fondation Louis Vuitton building sits beneath a majestic composition of large glass sails. The opaque facades, grouped in "icebergs", needed to be a brilliant white, forming a perfect fit on a highly complex geometry, while guaranteeing outstanding durability as requested by the Client for the whole building. We have taken part in this extraordinary adventure and tackled the challenge by proposing a material that meets the architect's aesthetic and technical expectations.
16,000 Ductal® panels, with a variety of geometries
The technical challenge posed by the random geometry of the 9,000 m² facade of the Fondation Louis Vuitton was met by manufacturing 19,000 Ductal® panels of which 16,000 with varying curvatures. Ductal® concrete rapidly proved itself the only material capable of meeting the expectations of this project due to its ultra-high performance in terms of durability, surface quality, thin panel thicknesses, casting-based manufacture and ductility. It has the important advantage of being able to withstand significant deformations without failure. Its organic fiber formula gives it a mineral materiality that is produced here in a very thin layer, just 25 mm, thus guaranteeing maximum weight reduction of the group of panels lining the facade.
While the material met the project's expectations, a process still had to be designed to enable industrial-scale manufacture of the 16,000 cladding panels, with random 3D geometries, and to fit them to the curve of the 9,000 m2 facade. It was obviously not feasible to make a number of moulds equal to the number of different geometries. The Lafarge team was able to propose an effective technical solution based on its considerable experience in materials manufacture and laying.
MSV: an innovative Vacuum Moulding process
We therefore developed the Vacuum Moulding (VM) process patented by Lafarge in 2008. This process uses a unique flexible mould that can be adapted to fit any curve. The desired geometry is provided by a CNC-machined polystyrene template: the deformable mould is positioned on this template using a combination of vacuum pockets. The flexible silicone mould provides a perfectly smooth, velvety surface with the result that each panel can be given a potentially unique curve, while still enabling Bonna Sabla, the partner precasting company, to limit the number of moulds used - a critical factor in the manufacturing cost.
Once laid out "flat", the geometry of the panels is therefore always the same: a rectangle measuring 1.5m in length and 40cm in height. Digital model software "Digital Project" is used to develop the pattern layout of the surfaces based on this rule. A Building Information Model (BIM) process is used to enter additional information, such as maintenance costs or the type of protection applied.
The digital model marks each panel with a code that contains all the data specific to the panel. This code is then used to track the panel end-to-end from manufacture to assembly. The Gehry Technologies team, originally from the Gehry Partners agency but now an independent entity, extracted this data and the geometry automatically from the model to enable Bonna Sabla to follow up with the manufacture.
Manufacturing and fitting tolerances were especially challenging: the inter-panel horizontal joint is 10mm, while the vertical joint is only 7mm. These limitations required the precaster to set up a strict geometry control process. Manufacturing expertise, combined with the fixing system proposed by the RFR and TESS facade design offices, ensured perfect visual continuity between the joints.
A perfect finish for a long-lasting aesthetic appeal
The aesthetic appeal of the 9,000m2 Ductal® panel facade is a fundamental component of the Frank Gehry project. Being displayed on the facade means that the panels are exposed to all types of weather, as well as to dirt and deposits, etc. In order to guarantee the skin's high durability, a water and oil repellent protection solution proposed by our partner Guard Industrie underwent extensive testing in their laboratory. Guard Industrie carried out UV weathering tests, XX and even tested the effect of bird droppings, given that the wood is full of birds! A sacrificial anti-graffiti coating has been applied in areas accessible to the public. This protection and finish therefore play a major role in ensuring long-lasting preservation of the aesthetic features that Ductal® offers the Fondation Louis Vuitton.
Where technical innovation meets architectural creativity... The Fondation Louis Vuitton building is a perfect illustration of the role played by Lafarge in making more beautiful cities!