Over 4.000 m² of Ytong fire walls for the future Lillenium shopping center

Xella actively participated in this demanding specification thanks in particular to the performance of its firewall solutions and its technical support which convinced the client Vicity and the manufacturer SOGEA Caroni / subsidiary of VINCI Construction France. Focus ...

It is presented as the future first commercial destination of the Lille European Metropolis ... Lillenium must open its doors to its first visitors in April 2020. An event because, on more than 56.000 m² on the immediate edge of the city center, the shopping center XXL will offer a hypermarket, 105 shops, a hotel, 19 restaurants around a common terrace of 320 m², 1 rooftop, a Children's City and 900 parking spaces, all spread over 6 levels. This spectacular project is the ultimate element in the new face of the Lille Sud district, which has been experiencing a major urban renewal for several years. To meet the challenge, Rudy Ricciotti, Grand Prix National d'Architecture, imagined and designed the building, and in particular its iconic draped structure, wishing to favor "light, fluidity, sky and minerality", while meeting today's environmental criteria.

1.000m³ aerated concrete for firewalls

To give substance to this ambition, the promoter Vicity, who is carrying out this project with the teams of SOGEA Caroni / subsidiary of VINCI Construction France in carrying out, has drawn up rigorous specifications: adopt a constructive method and efficient, responsible and adapted to the technical difficulties of the site.

These requirements were expressed in particular throughout the partitioning and separation of commercial cells. Very sensitive point in terms of security. It is the technical design office, Projex which prescribed aerated concrete for this use. "Vicity wanted easily modular dividing walls, while ensuring maximum fire protection," explains Alexandre Thomas, the main works manager of SOGEA Caroni / subsidiary of VINCI Construction France.

The choice fell on the Ytong Compact 20 solution. The mineral properties of the block perfectly suited to the tertiary sector (very high fire resistance, no toxic or flammable gas released), as well as the ability of the Xella group to produce in large quantities. were decisive arguments. Because in total, to partition the big hundred shops and restaurants, 4 m² of aerated concrete, or about 150 m1, will have been necessary.

"Particularly relevant" Xella technical service responses

The other advantage of Xella which made the difference from the study phase is the competence and responsiveness of its technical service. Ludovic Dupont, the sales engineer who follows the project for Xella: “To be as close as possible to expectations and stand out from the competition, our support started very early with the performance of a firewall analysis but also of a study relating to load lowering, one of the technical constraints of construction site. In these cases, the lightness of our product, which limits the overload of the tiles in the long term, makes all the difference. "The biggest difficulty to be solved was that of the linear overload because the floors were mainly treated with prestressed honeycomb slabs," adds Alexandre Thomas. And the technical elements including the implementation directives, in particular the vertical and horizontal chaining, transmitted by the Xella design office, were particularly relevant. "

An environmental choice

Cellular concrete also corresponded to one of the promoter's wishes, that of carrying out a project that was as environmentally friendly as possible. With Lillenium, Vicity hopes to obtain the “Very good” label from the BREEAM (Building Research Establishment Environmental Assessment Method) label. For this reason, the choice was made to opt primarily for local and perennial materials and to work on the optimization of water, waste and energy management. However, cellular concrete fits perfectly into this logic. Its environmental performance is expressed over the entire life cycle of the product: raw materials, manufacturing, transport, implementation, use and recycling. And as the architect Rudy Ricciotti wanted to emphasize the minerality, cellular concrete ticked all the boxes.

A simple and fast installation, adapted to the configuration of the site

At the time of the study, and even more since the launch of the works, the location is a central factor. This site is in fact located in the Lille-Sud district on a relatively narrow triangular plot, overlooking the ring road, bordered by two boulevards and a railroad track. Difficult under these conditions to ensure normal conditions of transportation and storage of materials. There is actually no storage area and especially a single access for the whole site. The vehicles were forced to parade one after the other and then passed the baton to the teams. Again, the choice of aerated concrete made work easier for Alexandre Thomas. “The blocks were supplied and stored on the job before the removal of our tower cranes. The Ytong constructive solution then responded well to my expectations thanks to its simplicity and speed of installation. Cellular concrete, which is lighter and easier to handle, cut and use, has greatly accelerated this sequence.

"We were well guided during the installation"

Especially since the implementation was carried out in the rules of art. “Franck Favier, our trainer and technician-demonstrator, intervened on several occasions to support the men of SOGEA Caroni / subsidiary of VINCI Construction France and the partner companies, describes Ludovic Dupont. In addition, the technical service produced layout plans for them which reassured everyone. This phase of the project took place in late 2018 and early 2019 without difficulty and on time. What the works manager would like to salute: “We appreciated the follow-up offered by the Xella technical service. His numerous visits notably helped to guide our partners in charge of laying. " An effective collaboration that will help give life to Spring 2020 in this new engine of Lille's economic life.