1866x
000505
2021-01-18

Dimensioning of Longitudinal Reinforcement for Serviceability Limit State Design 1

The SLS design checks to be performed according to EN 1992‑1‑1 include, for example:

  • Limitation of concrete stress σc according to 7.2 (1)
  • Limitation of steel stress σs according to 7.2 (4)
  • Minimum reinforcement min As according to 7.3.2 (2)
  • Limit diameter lim ds according to Table 7.2
  • Maximum rebar spacing lim sl according to Table 7.3
  • Limitation of crack width wk according to 7.3.1 (5) and 7.3.4
  • Limitation of deflection u according to 7.4

To fulfill the above-mentioned design checks for stress limitation, minimum reinforcement, and crack width, you can select the increase of the required longitudinal reinforcement from the ultimate limit state. However, not all designs must always be fulfilled. You can, for example, waive the design of concrete and steel stresses, if:

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

By deactivating the individual design checks (for example, the stress analyses) in the "Serviceability limit state" tab, they are not taken into account in the reinforcement design to fulfill the serviceability limit state design.

Part 2 describes the "Find the most economical reinforcement for crack width design" function.


Author

Mr. Meierhofer is the development leader of programs for concrete structures and is available for the customer support team in case of questions related to reinforced and prestressed concrete design.

Links
References
  1. EN 1992-1-1: Bemessung und Konstruktion von Stahlbeton- und Spannbetontragwerken – Teil 1-1: Allgemeine Bemessungsregeln und Regeln für den Hochbau. Beuth Verlag GmbH, Berlin, 2004