Construction Joints in Elevated Concrete and Metal Deck Floor Slab
Construction Joints in Elevated Concrete and Metal Deck Floor Slab
(OP)
I'm in the process of designing a elevated composite concrete and metal deck floor slab for a warehouse. This slab will have rolling fork lift loads. The floor has been designed with two mats of steel, 7 1/2" total concrete thickness and 50 ksi steel beams with a single row of shear studs on the beams. The question has come up concrening construction joints in the slab. Should there be any? If they are required where should they be located? Should the shear studs be staggered instead of just a single row?






RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
However, construction joints happen because you usually can't monolithically pour an entire floor slab at once. As long as the rebar used and the mix of the concrete is correctly designed, the cracking should be minimal. Let it crack and your designed steel will control the crack's width.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
thanks,
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
when is it preferable use shear studs as oppose to puddle weld?
thanks,
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
The shear studs are used to transfer force to/from concrete in a composite system. The shear studs are welded to the flange of a beam through the metal deck. In essence, it connects the metal deck also.
Puddle welds are used to transfer shear to/from a bare metal deck to a steel beam/joist.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
if i assume metal deck to be composite, i must use shear stud?
thanks,
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
metal deck only --> puddle weld, power actuated pins etc.
You can probably use shear studs on a bare metal deck, but that's just a waste of money.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
what is your opinion on using
a non-composite metal deck with concrete slab and top and bottom reinforcement and puddle weld.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
Make sure that your natural slab reinforcement is extended through the joints. If you don't have say - top bars at a joint, add some additional bars.
Keep the construction joints away from running parallel to and near to composite beams - place them beyond your effective flange width.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
Composite deck has embossments on it that allow the deck itself to resist loads compositely with the concrete for greater load carrying capacity of the deck/slab system. It does not need to be connected with shear studs, but doing so can increase its capacity a little bit due to end restraint.
Composite beams on the other hand must have shear studs so as to act compositely with the floor system.
So, you can use composite deck with noncomposite beams if you wish, though generally since they have to attach the deck down anyway, you might as well use shear studs instead of puddle welds and gain the composite beam action at very little extra labor/cost.
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
when is it preferable using non-composite deck like vulcraft type C?
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab
he used composite deck for the roof
and non-composite deck for 2nd floor slab with top and bottom rebars. this is the floor where the equipment is located.
is it preferable to use rebars instead of the metal deck for tension reinforcing, where you have heavy loads?
RE: Construction Joints in Elevated Concrete and Metal Deck Floor Slab