Innovation of Shear Connectors in Slim Floor Beam Construction

Table 1

Comparison of steel beam shapes used in the composite slim floor construction.

Steel beam shape	Tensile strength	Compressive strength	Slab restrain condition	Contact area	Concrete confinement	Workability
Asymmetric I-section	The bottom flange can resist the tensile stresses, but the section availability limits the required resistance.	The top flange provides compressive resistance.	Prevent up-lift force	Have a sizeable top contact area effective in the compression zone.	Partially provide concrete clamping	Provide the workability to cast in and install shear connectors as well as a continuing concrete slab.
Built-up I-section	All have a bottom plate, can resist the tensile stresses, and are flexible to the required resistance design.	The top flange provides compressive resistance.	Prevent up-lift force	Have a sizeable top contact area effective in the compression zone.	Partially provide concrete clamping	Provide the workability to cast in and install shear connectors as well as a continuing concrete slab.
Inverted T-section (or double T)	All have a bottom plate, can resist the tensile stresses, and are flexible to the required resistance design.	Only the top of the web can contribute to compressive resistance (small area in comparison).	Not prevent up-lift force	Not provided.	No concrete clamping	Provide the workability to cast in and install shear connectors as well as a continuing concrete slab.
Delta shape	All have a bottom plate, can resist the tensile stresses, and are flexible to the required resistance design.	The top edge provides compressive resistance in some cases.	Prevent up-lift force	Have a sizeable top contact area effective in the compression zone.	Provide clamping for infilled concrete	Need extra work to avoid the blanks or gaps and in installing shear connectors.
Hollow steel tube beam	All have a bottom plate, can resist the tensile stresses, and are flexible to the required resistance design.	The top edge provides compressive resistance in some cases.	Prevent the up-lift force	Have a sizeable top contact area effective in the compression zone.	No concrete clamping	Need extra work to avoid the blanks or gaps and in installing shear connectors.