In the 1950s, the hollow core slab was invented. The hollow core system was created to reduce the weight of the system's concrete. This concept eliminates and replaces concrete from the center of the slab, where it is less useful with a lighter material to decrease the dead weight of the concrete floor. However, these hollow cavities significantly reduce the strength of the slab to the cut and fire, thus reducing its structural integrity.
The bubble cover slab is the slab in which a part of the concrete is replaced by the plastic or ellipsoid bubbles that are made by the plastic waste material, which reduces the proper weight of the structure. The design of this type of slab is based on the euro and the British codes.
In the 1990s, a new system was invented, eliminating some of the problems. It is used in Dutch: German invented by JORGEN BREUNING. It blocks ellipsoids between the upper and lower reinforcement meshes, thus creating a natural cell structure, which acts as a solid slab. The slab is created with the same capabilities as a solid slab, but with a considerably lower weight due to the removal of excess concrete.