Dimensioning of Longitudinal Reinforcement for Serviceability Limit State Design 1

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Settings for Layout of Longitudinal Reinforcement

Tips & Tricks

000505 28 June 2012 Tips & Tricks Alexander Meierhofer Add-on Modules RF-CONCRETE CONCRETE Concrete Structures Eurocode 2

In RF-CONCRETE Members and CONCRETE and you have the option for ‘Dimensioning of Longitudinal Reinforcement for Serviceability Limit State’. You can select the layout criteria for the calculation of the longitudinal reinforcement in a details dialog box.

The SLS designs to be performed according to DIN EN 1992‑1‑1 include for example the

Limitation of concrete stress σ_c according to 7.2 (1)
Limitation of steel stress σ_s according to 7.2 (4)
Minimum reinforcement min A_s according to 7.3.2 (2)
Limit diameter lim d_s according to Table 7.2
Maximum rebar spacing lim s_l according to Table 7.3
Limitation of crack width w_k according to 7.3.1 (5) and 7.3.4
Limitation of deflection u according to 7.4

It is not required that all designs mentioned above are always fulfilled. So you can for example do without the design of concrete and steel stresses, if:

The internal forces have been determined according to the elasticity theory and not more than 15% have been shifted in the ULS design
The rules according to Chapter 9 in Eurocode 2 have been observed.

By deactivating several designs (for example stress designs) in the details dialog box for the reinforcement layout, programs will not consider these designs when determining the longitudinal reinforcement. However, the available results (for example concrete and steel stresses with loading in the serviceability limit state) are still displayed in Tables 4.1 to 4.4.

Part 2 will describe in detail the function ‘Find economical reinforcement for crack width design’.