Impossibly light concrete

The new Museum of Mediteranean Culture (MuCEM) in Marseille pushes concrete to its limits. Concrete achieves some amazing structural feats here while simultaneously ‘de-materialising’ into a delicate, coral-like structure.

The MuCEM sits at the entrance of Marseille’s old port and is the first museum in the world dedicated to Mediterranean cultures. Designed by architect Rudy Ricciotti in collaboration with Lafarge, it is made of 40,000 m3 of ultra high-performance concrete called Ductal. Reinforced by organic or metallic fibres, this patented concrete technology is unique for its elimination of the inherent weaknesses associated concrete as a material used in construction. For example, the improved micro-structural properties of Ductal’s mineral matrix mean it is able to support flexural and tensile loads – even after cracking.

Ductile behaviour such as this is a first for concrete. Furthermore, as Ductal exhibits almost no shrinkage or creep, it is ideal for pre-stressed concrete applications and the construction process is simplified by eliminating the need for reinforcing steel. The material is basically self-placing or dry-cast. Additional merits of the material include durability, resistance to corrosion, abrasion and impact, as well as allowing for some pretty stunning aesthetic. Ductal is able to achieve lighter, thinner and larger dimensions of concrete than ever before. The design of the MuCEM is particularly remarkable for its concrete building system, structural spans and its pioneering exterior skin made out of a delicate, filigreed concrete. This made possible with the material’s technology.

The building system is key to the design. The concrete floors of the MuCEM were manufactured first, set on scaffolding and then bound with pre-stressed Ductal concrete columns. As a result, visitors enjoy interior exhibition spaces that are large and remarkably column-free. The MuCEM also features a slender pathway linking the museum to the inner city of Marseille. With a length of 115 m and a height of 1,8 m, the super slender concrete pathway is a structural feat itself – a material experimentation with the slenderness and spans achievable by this high performing concrete.

The most eye-catching aspect of the MuCEM is of course its lace-like façade. The MuCEM is encased with a concrete mesh made from Ductal. This mesh is composed of 384 individual panels that cover two facades and the roof of the museum. The fine filigree of this concrete lace lets in light, air and the smell of the surrounding ocean while acting as a windbreak. The concrete takes on a new form and mimics the fine texture of ocean coral. The result is an inspired skin that creates dappled light and ethereal shadows.