Eurocode 2

Deep beam or shear walls are fairly common structural elements in the building construction industry of countries like France, Germany, Switzerland or Belgique, and thus, since the introduction of concrete structures in the 20 th century. Nevertheless, in Portugal and generally in southern European countries, reinforced concrete frames with a brick masonry infill is the foremost used building construction technique, with some punctually deep beams applications in recent years. Beyond that, Eurocode 2 is now the prevailing code in Europe for the concrete elements design. In the present paper, it is intended to compare the steel reinforcement amount defined for deep beams by the Eurocode 2, which is based in a finite element design approach or in the strut-and-tie model application, with the provisions defined in the French and Portuguese national codes. For the finite element design, a displacement based approach considering an isotropic linear elastic behavior is considered. For each code provisions, the reinforcement steel ratios are obtained and drawings are presented. The results allow understanding the economic impact of Eurocode 2 application in deep beams design.

A cement and concrete industry publication Foreword The introduction of European standards to UK construction is a signifi cant event. The ten design standards, known as the Eurocodes, will affect all design and construction activities as current British Standards for design are due to be withdrawn in 2010 at the latest. BS 8110, however, has an earlier withdrawal date of March 2008. The aim of this publication is to make the transition to Eurocode 2: Design of concrete structures as easy as possible by drawing together in one place key information and commentary required for the design and detailing of typical concrete elements. The cement and concrete industry recognised that a substantial effort was required to ensure that the UK design profession would be able to use Eurocode 2 quickly, effectively, effi ciently and with confi dence. With support from government, consultants and relevant industry bodies, the Concrete Industry Eurocode 2 Group (CIEG) was formed in 1999 and this Group has provided the guidance for a coordinated and collaborative approach to the introduction of Eurocode 2. Part of the output of the CIEG project was the technical content for 7 of the 11 chapters in this publication. The remaining chapters have been developed by The Concrete Centre.

The reinforced concrete structures must be analyzed and designed according to the provisions of relative design standards. Design codes are the documents which are established for the design of a respective structure. Most of the countries have established their own design codes according to their local geographical, topographical and climatic conditions. However, such multiplicity in design criteria may lead towards the misperception of the structural engineers who are working on a global platform. Even though Indian Standards provides adequate guidelines for construction of buildings in India, there are some International standards which covers supplementary parameters that are not included in IS codes. Thus, the efforts are made to provide a comparative study on analysis and design parameters of R.C.C. beam according to the Indian code (IS456:2000) and European code (Eurocode 2 EN 1992-1-1). Such comparison will ensure the effectiveness in economical structural design worldwide.

Since the predicted creep compliance according to the Eurocode 2 does not take the effect of admixtures into consideration, a study of the influence of admixtures on creep is performed. Based on a large database established from international laboratories and research centers, a comparison between the experimental creep and the creep predicted by the Eurocode 2 is performed using statistical methods. An in-accurate estimation is detected based on the type of the admixture used. The use of a combination of water reducer and silica fume as admixtures leads to an underestimation of the creep compliance.
In order to overcome this difference, a calibration is required by adding corrective coefficients to the Eurocode 2 equations, taking into consideration the type and percentage of admixtures. The Approximate Bayesian Computation method based on the rejection algorithm is applied in order to calculate the corrective coefficients.
After implementing the corrective coefficients in the Eurocode 2 compliance formula, and in order to evaluate our updated Eurocode 2 creep model, statistical methods are used. An improvement in the results is clearly shown. Using the large experimental database, the present study demonstrates the importance of the Bayesian model assessment for the updating of the Eurocode 2 creep model, taking into account the effect of admixtures. The adoption of such a design approach would improve long-term serviceability of structures subject to creep.

La spécification de la DUREE D’UTILISATION de PROJET et des
CLASSES D’EXPOSITION est de la RESPONSABILITE DU MAITRE
D’OUVRAGE qui se trouve engagé dans l’expression des risques de
dégradation et des conditions d’exploitation de la structure qu’il commande.
Chaque partie d’ouvrage peut être soumise simultanément à plusieurs
agressions et attaques. Il convient donc, pour chaque partie d’ouvrage, de
déterminer l’ensemble des classes d’exposition à considérer en application de
l’Eurocode 2, de la norme NF EN 206-1 et du fascicule 65 du CCTG (pour les
ouvrages de Génie civil).

Serviceability limit state analysis is an important part of the design of reinforced concrete structures in order to meet the requirements of functionality, durability and aesthetics of the structure. The application of European standards (Eurocodes) in construction in the Republic of Serbia has started recently and there are still disagreements in the interpretation of certain provisions of the standards. On a simply supported reinforced concrete beam at an authoritative cracked cross-section was analyzed the applications of different combinations of permanent and variable actions for purpose of calculation characteristic crack width and deflections at the moment after inflicting load of a class S4 structure and at the end of service life. The results of the calculation according to Eurocode are compared with the results of the calculation according to the Standard for Concrete and Reinforced Concrete from 1987 for interpretation and selection of the relevant combination of actions.

Influence of non-uniformity of cracking on calculation of deflection of reinforced-concrete elements, according to eurocode 2 Wpływ nierównomierności zarysowania na obliczanie ugięć elementów żelbetowych według eurokodu 2 Abstract Formulae for the deflection of two examples of isostatic systems (simply supported beam, cantilever) were derived, accounting for influence of distribution of bending moments on cracking and beam stiffness distribution, according to EC2. Numerical analysis of the problem for the same two examples as well as for two further hyperstatic systems was performed using an iterative FEM algorithm. The influence of non-uniformity of cracking on deflection and distribution of bending moments was shown to be negligible in typical practical design problems, therefore also an estimation of deflection on the basis of the distribution of bending moments and the value of the factor α k obtained from linear solution (before redistribution) is shown to be justified.