STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

For detailing please see structural drawings attached at the end of SP34. These drawings may teach you better detailing skills.

In yr case it seems bottom reinf is 10 cm2 for mid span of end span , ...

Deflection is serviceability requirement and as per IS 456 this needs to be checked at working loads as evident from clause 35.4 on partial safety factors for Loads Table 12 ( relating clauses 18.3 ...

Er Ramu

Cantilever slab

Your calcs are OK and depth rightly revised . Cantilever slabs must be provided with liberal depth as reinf is at top and chances of reinf getting little down at site a ...

One thing must be borne in mind that while making deflection check using load factor = 1.0 , pl calculate pt and see modification factor and do not further calculate Ast , Since Ast to be provided has ...

Er Ramu

Calculations for deflection Chek purposes:

As per calcs fm u , pt = 0.128 for LF =1.0

Refer to chart figure 3 , the multiplier is 2.0

The effect of continuity cannot be taken t ...

Er
Pl apply modification factor ( a multiplier to value 26 ) , based on % tension reinf pt considering a slab thick Ness of 115mm and load factor =1.0

Deflection ccalculation for two way slab :
Refer any text book on rcc design and chapter two way slabs you can easily get the computations from first principle.
Just to illustrate :

For ss cond ...

Yes , 115 mm th slab is OK as it is two way with continuity at edges AND it is in accordance with clause 23.1 of IS 456.

Only in above clause especially for solid slabs , overall depth D is taken ...

Past Discussion on this is reproduced hereinunder :
Dear All,

The practice being followed in CPWD is shared with SEFI community:
1. Provide specified concrete mix (i.e. richer mix) at column loca ...

Er Ramu

For Two way slabs see cl 23.1 IS 456 ,
L/D = 28 for simply supported edges
L/D = 32 for continuous edges
D here is overall depth

Most important in deflection check is that % reinf ...