Nationally Determined Parameters of Eurocode 2 : A Comparison among Seven European Countries

Abstract: Since the main ambition of the European community is to create a Single Market among the European countries, a unified set of structural design codes recently became mandatory to use. These standards, the Eurocodes, contain Nationally Determined Parameters (NDPs) that have to be fixed by the National Standard Bodies in the various countries. The investigation of the adopted values for Eurocode 2 in seven European States has been carried out i  this thesis for quantifying the differences that arise from the selected values of these parameters. The aim of this investigation was to find out which countries are advantaged or disadvantaged by the choice of the value of these parameters. The analysis has been limited to the Part 1-1 of Eurocode 2 that concerns “General Rules for Buildings” and the most important parts of Eurocode 0 and 1. The investigated countries were Denmark, Finland, France, Germany, Italy, Sweden and the United Kingdom. Even if these countries represent only seven out of 27 EU States, this comparison gives a good view of the European situations since they cover nearly half of the continental concrete consumption. The analysis includes a theoretical comparison of the national choices of all the 170 national parameters as well as their influence on the more important formulas contained in the Code. Five practical case studies concerning the design and the verification of some structural elements have been carried out in order to study the differences in real and common design situations. Through all the work, the different choices have been compared to the recommended values proposed by the Eurocode that have been used as a mean of comparison. Due to the large number of parameters and the complexity of the problem it has not been possible to estimate and quantify general trends of differences for the countries although Finland, France, Italy and the United Kingdom have been found to have, in general, more disadvantageous choices than the other States. Moreover, Denmark and Germany show variable trends (both above and below the recommended values) while Sweden is always close to the recommended values. The results that have been found show that still a lot of work and research has to be done in order to achieve an even set of structural standards for the design of concrete structures. A list of more important national parameters has been presented as well as a proposal to convert some national parameters to fixed ones. The analysis and the results that have been obtained give details and indications about the future works that need to be done for decreasing the differences among the European countries.