The challenge

Taking up tension loads by steel and compression loads by concrete, both materials are perfect partners for a composite structure. Can a light-weight lattice girder consisting of an upper and a lower chord and filling bars be produced without welding?

The invention

Concrete, when used as an infill in a chamber of a hollow section, can substitute a rather expensive welded connection between the chords and the filling bars in a new kind of composite structure. The RES-Hollow Ceiling I uses a multitude of girders layed out side by side to form a hollow space between the upper and the lower chords.

The advantages

  • Substitution of welded connections in a new composite technique
  • Cost effective method to produce wide-span girders
  • Improved fire resistance in comparison to a steel girder

The applications

  • Girders for a wide range of spans
  • Creation of a hollow ceiling with concrete slabs