Table
Bending moment coefficients for flat slabs
End support/slab connection First Interior Interior
 interior spans supports
Pinned Continuous support
End End End End support span support span
Moment 0
G.GB6FI G.G4FI G.G7SFI G.GB6FI G.G63FI
G.G6SFl
Notes
1 Applicable to slabs where the area of each bay exceeds 30 m2, Qk, < 1.25 Gk and qk < 5 kN/m2
2 F is the total design ultimate load, l is the effective span
3 Minimum span > 0.85 longest span, minimum 3 spans
4 Based on 20% redistribution at supports and no decrease in span moments
Whichever method of analysis is used, CI. 9.4.1 requires the designer to concentrate the reinforcement over the columns. Annex I of the Eurocode gives recommendations for the equivalent frame method on how to apportion the total bending moment across a bay width into column and middle strips to comply with CI. 9.4.1. Designers using grillage, finite element or yield line methods may also choose to follow the advice in Annex I to meet this requirement.
Eurocode 2 offers various methods for determining the stressstrain relationship of concrete. For simplicity and familiarity the method presented here is the simplified rectangular stress block (see Figure 2), which is similar to that found in BS 8110.
The Eurocode gives recommendations for the design of concrete up to class C90/105. However, for concrete strength greater than class C50/60, the stress block is modified. It is important to note that concrete strength is based on the cylinder strength and not the cube strength (i.e. for class C28/35 the cylinder strength is 28 MPa, whereas the cube strength is 35 MPa).
% redistribution 
1 6 (redistribu 
tion ratio)  K' 
G 
1.GG 
G.2GBa 
1G 
G.9G 
G.182a 
15 
G.BS 
G.16B 
2G 
G.BG 
G.1 S3 
25 
G.7S 
G.137 
3G 
G.7G 
G.12G 
Key a It is often recommended in the UK that K should be Uimited to 0.168 to ensure ductile failure 
Table 5
z/d for singly reinforced rectangular sections
Table 5
z/d for singly reinforced rectangular sections
K 
1 z/d 
■ K 
\z/d 
s G.GS 
G.9SGa 
G.13 
G.B6B 
G.G6 
G.944 
1 G.14 
G.BS6 
G.G7 
G.934 
G.1 S 
G.B43 
G.GB 
G.924 
G.16 
G.B3G 
G.G9 
G.913 
1 (G.17 
G.B16 
G.1G 
G.9G2 
G.18 
G.BG2 
G.11 
G.B91 
1 (G.19 
G.7B7 
G.12 
G.BBG 
G.2G 
G.771 
Key a Limiting z to 0.95d is not a requirement of Eurocode 2, but is considered to be good practice 
Table 6
Minimum percentage of reinforcement required
Table 6
Minimum percentage of reinforcement required
fck 
l/ctm 
1 Minimum % (0.26 fctm /fyka ) 
25 
2.6 
G.13% 
28 
2.8 
G.14% 
30 
2.9 
G.1 S% 
32 
3.G 
G.16% 
35 
3.2 
G.17% 
40 
3.S 
G.18% 
45 
3.8 
G.2G% 
50 
4.1 
G.21% 
Key a Where fyk = 
SGG MPa 
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