Deflection 1
Eurocode 2 has two alternative methods of designing for deflection, either by limiting span-to-depth ratio or by assessing the theoretical deflection using the Expressions given in the Eurocode. The latter is dealt with in detail in Chapter 8, originally published as Deflection calculations7.
The span-to-depth ratios should ensure that deflection is limited to span/250 and this is the procedure presented in Figure 3.
Figure 2
Simplified rectangular stress block for concrete up to class C50/60 from Eurocode 2
Figure 2
Simplified rectangular stress block for concrete up to class C50/60 from Eurocode 2
Figure 3
Procedure for assessing deflection
Figure 4
Determination of steel stress
Figure 3
Procedure for assessing deflection
- ^ The Eurocode is ambiguous regarding linear interpolation. It is understood that this was the intention of the drafting committee and is in line with current UK practice.
Figure 4
Determination of steel stress
- To determine stress in the reinforcement (ss), calculate the ratio Gk/Qk, read up the graph to the appropriate curve and read across to determine ssu.
ss can be calculated from the expression: ss = ssu (^s,req ) (-1)
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