Built-up support member

A built-up support member for carrying bending loads formed of two coacting load carrying separate elements (1, 2) one superimposed on the other, with the separate elements (1, 2) absorbing normal forces caused by bending, said separate elements having facing surfaces, first means for transmitting shear forces acting at the facing surfaces between the separate elements (1, 2), said first means comprising that said facing surfaces have complementary shaped surfaces comprising projections and recesses, second means for applying prestressing force between said separate elements with said second means extending transverse said facing surfaces, said complementary shaped facing surfaces being one of rounded surfaces or obliquely disposed surfaces, said separate elements (1, 2) comprise an upper element (2) superimposed on a lower element (1), said upper element having an upper planar surface opposite said facing surfaces, said lower element having a second surface opposite said facing surfaces, said second means comprises clamping means extending between and bearing against said upper element (2) and said second surface of lower element (1) at least at one of said projections and recesses, and said clamping means extending perpendicularly of said upper planar surface.