METAL JOINING PART FOR ASSEMBLING A MODULAR STRUCTURAL UNIT FOR CONSTRUCTION, AND ASSOCIATED UNIT AND STRUCTURE

The invention relates mainly to a metal joining part for assembling a structural unit for construction, which is essentially characterized in that it has three fastening flanks (11da, 11db, 11dc) that are able to fasten three panels (15, 16) to said joining part (11d) and are each provided with at least one smooth or tapped bore (11da', 11db', 11dc') which defines a fastening axis (Χ, Υ, Ζ) through clamping of the flank (11da, 11db, 11dc) in question against one of the three panels (15, 16), and in that the three fastening flanks (11da, 11db, 11dc) comprise a first fastening flank or central base (11da) that is able to press in a clamping fastening manner against a first panel, a second fastening flank or first fastening tab (11db) that is able to press in a clamping fastening manner against a second panel (15) and has a tapped bore (11db'), and a third fastening flank (11de) or second fastening tab (11de) that is able to press in a clamping fastening manner against a third panel (16) and comprises a smooth bore (11dc'). The invention also relates to a modular structural unit for construction that includes said metal joining part, three joined-together panels and a second metal part, the bores in the first and second metal parts on either side of a panel having opposite threads so as to allow fastening by controlled clamping of the panel. Finally, the invention relates to a modular construction structure that is made of a series of boxes, the tops of which consist of the structural unit defined above.