Composite Beam Design with Formed Steel Deck utilises the combined strength of a steel beam and a concrete slab to carry floor loads more efficiently. The formed steel deck serves as permanent formwork during construction and as slab reinforcement in service. Per AISC-ASD provisions, this approach ensures stresses remain within safe limits under service loads while optimising material use.
How Composite Beam Action Works
In a non-composite system, the steel beam and concrete slab act independently. In a composite system, shear connectors (typically headed studs) welded to the top flange of the steel beam mechanically connect it to the slab, forcing them to act as a single structural unit. The concrete resists compression and the steel resists tension, leveraging the strengths of both materials.
Composite action typically reduces the required steel beam size by 20–40% compared to the non-composite case, resulting in significant material and cost savings for multi-storey floor systems.
Formed Steel Deck Considerations
When the slab is formed on metal deck, the deck ribs run either parallel or perpendicular to the steel beam. AISC-ASD provides reduction factors for shear stud strength when studs are placed in deck ribs, as the confined geometry reduces stud effectiveness. The sheet accounts for both rib orientations.
What This Sheet Calculates
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