Main beams or girders most commonly having , L, ⊥, T, H and box-type,sections are used as side beams, roofing elements or slabs and are ususally assembled together with hollow-core slabs, TT roofing elements, double cantilever trusses, wing-contour trusses and so on.
They are designed to meet several requirements:
light weight / slim section;
being aesthetically pleasant.
They geometry can vary in accordance with design spans and loads, with an extremely wide range of dimensions. Such beams are designed to have the minimum extrados overall dimensions, they assure excellent performance in terms of design spans and fire resistance, allowing to use a very spacious structural pattern.
When used as slabs, they are equipped with jetting stirrups to ease the merging with the on-site integrative casting.
They can be positioned simply leaning (onto the walls) by means of suitable foundation bolts in seismic prone areas or wherever requested.