Apparatus and method for composite concrete and steel floor construction

Abstract

The composite floor system of the present invention comprises a plurality of joists at least partially embedded in the concrete slab of the floor system. In the most preferred embodiments of the present invention, each of the joists is formed from a single piece of cold rolled sheet metal and, in at least one orientation, exhibits a substantially “Z-shaped” or “C-shaped” cross section along a longitudinal axis. In addition, for certain applications, a novel mounting bracket may be affixed to each end of the joists to provide for an underslung installation.

1 . A composite steel and concrete floor construction comprising: 
 a poured concrete slab;    a plurality of individual laterally placed, parallel disposed, and supported joists, wherein each of said plurality of joists comprises an upper chord and a lower chord joined by a body portion, and each upper chord and each lower chord is substantially perpendicular to said body portion, wherein at least a portion of said upper chord is embedded in said concrete slab; and    wherein each of said plurality of joists comprises a substantially Z-shaped or C-shaped cross section about a longitudinal axis of said plurality of joists.    
     
     
         2 . The composite steel and concrete floor construction of claim one wherein said upper chord defines a plurality of apertures and wherein each of said plurality of apertures provides a connection between a first portion of said concrete slab and a second portion of said concrete slab; and 
 a reinforcing mesh at least partially supported upon said upper chords of said plurality of joists and hanging generally in a catenary shape therebetween and being fully embedded in said slab.    
     
     
         3 . The composite steel and concrete floor construction of  claim 1  wherein said upper chord comprises a plurality of concrete-engaging mechanisms.  
     
     
         4 . The composite steel and concrete floor construction of  claim 3  wherein said plurality of concrete-engaging mechanisms comprises a plurality of dimples.  
     
     
         5 . The composite steel and concrete floor construction of  claim 1  further comprising a reinforcing mesh at least partially supported upon said upper chords of said plurality of joists and hanging generally in a catenary shape therebetween and being fully embedded in said slab.  
     
     
         6 . The composite steel and concrete floor construction of  claim 1  wherein each of said joists is completely formed of a single piece of cold rolled sheet metal.  
     
     
         7 . The composite steel and concrete floor construction of  claim 1  wherein said connection between a first portion of said concrete slab and a second portion of said concrete slab comprises an additional shear transfer mechanism.  
     
     
         8 . The composite steel and concrete floor construction of  claim 1  further comprising a plurality of support structures supporting each of said plurality of joists.  
     
     
         9 . The composite steel and concrete floor construction of  claim 1  wherein each of said upper chord and said lower chord of each of said plurality of joists further comprise a flange extending away from each body portion of each said plurality of joists.  
     
     
         10 . The composite steel and concrete floor construction of  claim 9  wherein said body portion of each of said plurality of joists is substantially suspended between said plurality of support structures by at least two mounting brackets.  
     
     
         11 . The composite steel and concrete floor construction of  claim 1  wherein each of said plurality of joists exhibits rotational symmetry about said longitudinal axis.  
     
     
         12 . The composite steel and concrete floor construction of  claim 1  wherein each of said plurality of joists exhibits reflective symmetry about said longitudinal axis.  
     
     
         13 . A composite steel and concrete floor construction comprising: 
 a concrete slab;    a plurality of individual laterally placed, parallel disposed joists, wherein each of said plurality of joists comprises a upper chord and a lower chord joined by a body portion, and each upper chord and each lower chord is substantially perpendicular to said body portion, wherein each of said plurality of joists comprises a substantially Z-shaped or C-shaped cross section about a longitudinal axis of said plurality of joists, wherein said upper chord comprises a plurality of concrete-engaging mechanisms, wherein at least a portion of said upper chord of each of said plurality of joists is embedded in said slab; and    a reinforcing mesh at least partially supported upon said upper chords of said plurality of joists and hanging generally in a catenary shape therebetween and being fully embedded in said slab.    
     
     
         14 . The composite steel and concrete floor construction of  claim 13  wherein said plurality of concrete-engaging mechanisms comprises a plurality of dimples.  
     
     
         15 . The composite steel and concrete floor construction of  claim 13  wherein each of said joists is completely formed of a single piece of cold rolled sheet metal.  
     
     
         16 . The composite steel and concrete floor construction of  claim 13  wherein each of said plurality of joists exhibits rotational symmetry about said longitudinal axis.  
     
     
         17 . The composite steel and concrete floor construction of  claim 13  wherein each of said plurality of joists exhibits reflective symmetry about said longitudinal axis.  
     
     
         18 . The composite steel and concrete floor construction of  claim 13  wherein said body portion of each of said plurality of joists is substantially suspended between said plurality of support structures by at least two mounting brackets.  
     
     
         19 . A method comprising the steps of: 
 supporting a plurality of joists between a plurality of support structures, each of said plurality of joists comprising a substantially “Z-shaped” or “C-shaped” cross section along a longitudinal axis;    placing a plurality of removable spanner bars extending between said plurality of joists;    placing a support platform over said plurality of removable spanner bars; and    pouring a concrete slab over said support platform, thereby embedding at least a portion of each of said plurality of joists.    
     
     
         20 . The method of  claim 19  further comprising the steps of: 
 waiting for said concrete slab to cure;  
 removing said plurality of removable spanner bars; and  
 removing said support platform.  
 
     
     
         21 . The method of  claim 19  wherein said support platform comprises a plurality of plywood sheets.  
     
     
         22 . The method of  claim 19  wherein said step of supporting said plurality of joists between a plurality of support structures comprises the steps of: 
 affixing a first mounting bracket to a first end of each of said plurality of joists and affixing a second mounting bracket to a second end of each of said plurality of joists; and  
 affixing each of said first and second mounting brackets for each of said plurality of joists to said plurality of support structures, thereby suspending each of said plurality of joists between said plurality of support structures.  
 
     
     
         23 . The method of  claim 19  further comprising the step of suspending a reinforcing mesh at least partially upon said upper chords of said plurality of joists prior to pouring said concrete slab, said reinforcing mesh hanging generally in a catenary shape therebetween and being fully embedded in said concrete slab.  
     
     
         24 . The method of  claim 19  further comprising the step of engaging at least a portion of said concrete slab with a plurality of concrete-engaging mechanisms, said plurality of concrete-engaging mechanisms being formed in an upper chord of each of said plurality of joists.