ENDESA BUILDING IN MADRID

The main structural feature of the building lies in the use of single-span, statically determined beams bearing on closely spaced columns in the facades.  In this composite beam assembly, the prestressed concrete part supports the slab system which could be carried out by means of hollow clay blocks thanks to the fact that the beams are spaced at only 1.20 m. These bottom flanges are cut at a distance of 1.60 m from the columns; only the steel profile reaches the columns. This creates large continuous spaces alongside the facades where the service ducts can be installed.

A layer of in-situ concrete, which monolithically solidifies the structure, serves as bracing element for the slender steel columns and transfers the horizontal actions to the concrete cores which deliver them to the basement.

The thus obtained beam stiffness is really remarkable in view of the span-depth ratio and ensures perfect functionality.