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Code provisions for a simplified check of the long‐term deflection of concrete structures are generally developed for predefined values of the relevant input parameters. Deflection calculation may be of interest to account for different design situations. EN 1992‐1‐1 advocates the integration of curvatures calculated using the effective modulus of concrete. This paper presents an efficient procedure for calculation of the long‐term deflection due to a sustained load. A nondimensional analysis of the mean curvature is applied to evaluate the deflection. The deflection is calculated using a set of algebraic expressions. The result is close to the value obtained by the numerical integration of curvatures. The values of relevant parameters in the expressions may be selected within the common range for the design of engineering structures. The efficiency of the deflection prediction based on the integration of curvatures is tested on the available experimental data. In the first approach, the measured material properties are used. In the second approach, the required values are derived from EN 1992‐1‐1 expressions to predict the material properties.

Deflections are among the most complex aspects of reinforced concrete behavior. Furthermore, deflection control is increasingly a governing criterion in design, especially in the case of two‐way members such as flat slabs or edge‐supported slabs. However, simple and theoretically sound and adequately verified methods for calculating deflections of two‐way reinforced concrete members have been lacking. Therefore, in this study, a novel method is proposed for deflection control of two‐way slabs. The method is an extension of the ζ‐method (as defined by Eurocode 2 and the fib Model Code 2010) of interpolating deflections between the uncracked and fully cracked state. As a basis, the method uses elastic deflections that are obtained through linear elastic analyses in finite element software. The elastic deflection is then adequately transformed based on the properties of a representative section, to account for cracking, shrinkage and creep according to a modified version of the ζ‐method. Finally, the method is validated against available experimental results from literature, obtaining satisfactory precision and accuracy. The method proposed in this study aims at providing an easy‐to‐use tool for designers carrying out deflection control of two‐way reinforced concrete slabs.

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