This type of floor has its resistive elements or nerves in both directions forming a grid, so called Bidirectional or Waffle Slabs.
Constituitvos elements of infilling are called caisson type may be recoverable, which is called the bathtub, can be of polyester and have a central hole. On this hole is injected compressed air in order to separate the concrete of the slab.
The non-recoverable are made of lightweight concrete blocks or Styrofoam.
Resistant Structure
Lacunar: The bearing capacity of the slab is achieved in the form of square coffers. When the nerves have the same length and the same load, the deformation also needs to be more homogeneous in both directions.
Box: The set of nerves arranged between four pillars or supports. Ratio for a square box, the girders are working equally to the charges, therefore, each column receives a quarter of the shares is subject to this set. This cast is a large monolithic structural whole.
Support Bands
The bands act as support beams, we note that sections of the head are subjected to shear and negative bending moments. With the effort of working your own concrete cutting of the section.
As you approach the pillar, the nerves of the support band require any concrete surface to assist in the shear, so it performs its interaxis solid.
Longitudinal Armor
The nerves of the support band work like a flat girder, and the central band act as beams. The way in which the slab is constructed determines that all links or nodes are embedded.
The bending moment diagram are similar for both families of nerves, characterized by negative bending moments in the heads of the bars and positive in the midpoint.
