Thickness of Transfer Slabs
Thickness of Transfer Slabs
(OP)
To limit deflections in uniformly loaded slabs, I'm aware of the rules for span/effective depth ratios i.e. 20 for simply supported slabs and 26 where continuous(UK Code). Can span/effective depth ratios be applied for transfer slabs given the non-uniform loading. The code says that deflections do not need to be checked where S/ED ratios are used but i have some reservations about applying this to transfer slabs. Any thoughts






RE: Thickness of Transfer Slabs
RE: Thickness of Transfer Slabs
RE: Thickness of Transfer Slabs
If you can design the slab to meet all of the strength requirements of the code, I do not think deflection will govern simply because loads are not uniform.
Having said that, I prefer a rigid transfer structure and might be inclined to beef it up a bit because of its importance. You also may require more cover over the reinforcement for fire protection.
BA
RE: Thickness of Transfer Slabs
Progressive loading of transfer slabs has to be considered. We usually use post-tensioning, so the loads can be balanced incrementally.
RE: Thickness of Transfer Slabs
What you have to remember is that deflection of the transfer member is support settlement for the floors above. So you need to calculate deflections and limit them much more severly than for a general slab or beam. Plus you need to detail the reinforcement for the floors above allowing for support settlement. Support settlement can also contribute to ponding on rooves.
The b=next Australian code limits deflection for transfer members to L/500 if support settlement is being allowed for in the design of the floors above and L/1000 if it is being ignored. Therse figures cannot be determined from L/D ratios. Deflections must be calculated.
RE: Thickness of Transfer Slabs