Concrete On Metal Deck Slab

The requirements for shoring are based on the ability of the decking to sustain the weight of the fresh concrete plus a construction live load of 20 pounds per square foot without exceeding an allowable unit stress of 20 000 psi.

Concrete on metal deck slab.

The determining factors for selecting the proper composite deck are the depth of the slab weight of the concrete normal weight or lightweight the support spacing and the uniform load you are trying to support. As a contractor therefore don t be afraid to talk to the engineer about all this. Concrete slab on metal deck cracking. The convention in design of composite deck slab systems is to use the transformed section to convert the area of steel into an equivalent area of concrete.

The decking not only acts as permanent formwork to the concrete but also provides sufficient shear bond with the concrete so that when the concrete has gained strength the two materials act together compositely. They don t have any real design guidance concerning deflection or crack control or how the tolerances can be different between the concrete and the steel. The transformed section properties are then used to determine the nominal bending moment and predicted deflections for the composite deck slab section. Slab thickness is measured from bottom of ribs.

Composite steel deck is a permanent concrete form and provides positive reinforcement while it eliminates the time and cost of wood forming. The shear capacity of the composite deck alone is added to the beam shear capacity of the concrete to arrive at the total beam shear capacity of the slab. Engineers who design slabs on metal deck aren t thinking about the contractor. Composite slabs consist of profiled steel decking with an in situ reinforced concrete topping.

Casting the slab in strips parallel to the joists would eliminate negative moment cracking over the beams since the concrete would not have set and over the columns there would be a nice straight joint. Composite floor decks are available in 1 1 2 2 or 3 depths. Composite floor decks have embossments that grip the concrete slab and they are typically reinforced with rebar or wire mesh which creates a strong bond with the concrete floor. 3 composite floor deck panels are primarily used for pouring concrete slabs.

In the composite deck worksheet since the composite deck is interlocked or engaged with the concrete the deck is assumed to function as the positive moment bottom face slab reinforcing. Composite floor decks are mostly used to create a composite structure with the concrete slab that is poured upon it.