4,500 Cobiax void formers to lighten the lobby slab

The lobby slab was built. Located on top of the Elysée Museum, this slab carries the heavy live loads linked to the program of the ground level. It also crosses large spans needed for the activities of the photography museum.

Due to the coordination with techniques such as ventilation, this slab could not be strengthened with beams. Placing Cobiax void formers was thus necessary to reduce its self-weight. Therefore, the 60-cm of concrete needed for the flexural-resistance was compensated by the 40-cm diameter voids distributed were the loads effects allowed it.