designing cantilever part of RC slab - help
designing cantilever part of RC slab - help
(OP)
Hello, Im hoping for some help.
English is not my first language so sorry in advance foor poor language.
My upper floor is larger than a floor bellow so I have to deal with a cantilever part of a slab that is 200 mm thick. Cantilever is only 1 m long, but it is loaded in the end by a wall (mansonry + RC vertical ties) that is supporting a part of the roof structure.
I have calculated that design force in a RC column/vertical tie is 65 kN.
I have controlled punching shear at the edge of a slab and shear strenght of a slab at a wall bellow.
Im wondering - for control of shear - can I consider that slab is 1000 m wide and 200 mm high cross section?
Can I consider that single/point load (from column at the end of cantilever slab) is transfered at 30 degree so my effective width for slab control is 1200 mm (for conservative reasons I took 1000 mm).



English is not my first language so sorry in advance foor poor language.
My upper floor is larger than a floor bellow so I have to deal with a cantilever part of a slab that is 200 mm thick. Cantilever is only 1 m long, but it is loaded in the end by a wall (mansonry + RC vertical ties) that is supporting a part of the roof structure.
I have calculated that design force in a RC column/vertical tie is 65 kN.
I have controlled punching shear at the edge of a slab and shear strenght of a slab at a wall bellow.
Im wondering - for control of shear - can I consider that slab is 1000 m wide and 200 mm high cross section?
Can I consider that single/point load (from column at the end of cantilever slab) is transfered at 30 degree so my effective width for slab control is 1200 mm (for conservative reasons I took 1000 mm).









RE: designing cantilever part of RC slab - help
RE: designing cantilever part of RC slab - help
Do slabs have such a large shear capacity?
Not really my field but I was always wondering how do they solve situations like this.
RE: designing cantilever part of RC slab - help
I was thinking about using rebars (red line) as bending moment reinforcement above a support (wall) and at the end as shear reinforcement (bent at 45 degrees).
Thoughts?
RE: designing cantilever part of RC slab - help
I'm fairly certain we have hashed this out in a couple of threads within the last few months.
RE: designing cantilever part of RC slab - help
With the slab thickness and loading that you have, I doubt that you would need shear reinforcing. But if you do, either thicken the slab or add ties. Your detail would not be adequate in my opinion.
RE: designing cantilever part of RC slab - help
as far as I can see the top rebars are anchored and can have two functions:
- as bending moment tension reinforcement at the top of a slab above a wall
- as a shear reinforcement (bent part) that is also anchored
RE: designing cantilever part of RC slab - help
To develop shear capacity as well as flexural capacity you need tension face reinforcement. You have none.
You bars are doing nothing after they kink downwards other than creating a difficult reinforcing bar bend requirement.