Open web dissymmetric beam construction

摘要

An improved structural framing system and associated method of construction is disclosed wherein an open web dissymmetric steel beam fabricated having a plurality of trapezoidal openings formed along the web thereof between a narrowed, thickened top flange and a widened bottom flange is horizontally disposed and supported between adjacent vertical columns erected on conventional foundations. The dissymmetric beam is preferably fabricated from a standard rolled, wide flange beam split longitudinally according to a specific cutting pattern to produce substantially identical open web beam sections having a single wide flange. A flat bar plate is then welded along the open web beam section to provide the top flange and thereby produce the dissymmetric beam for use in the present system. Standard hollow core sections of precast concrete plank are assembled together perpendicularly to the open web dissymmetric beam and supported upon the bottom flange on either side thereof so that the open web of the beam is centrally disposed between end surfaces of the plank sections in substantially the same horizontal plane. A high-strength grout mixture applied to the assembled beam and plank sections is made to flow completely through the web openings in a circulatory manner thereby creating a substantially monolithic concrete encasement around the dissymmetric beam that improves the resulting composite action and mechanical interlock between the steel beam and concrete plank and prevents loss of strength due to separation of the grout from either side of the beam.