Comparison of Design of Rectangular Cross Sections Reinforced Only in the Tension Zone According to PBAB/87 and Eurocode 2

Abstract

The long-term experience and practice created in a country or region which translates into the local standards is an inseparable part of the principles of the engineering profession. This is precisely expressed in our country, a country with a rich engineering tradition, through our standards, where the orientation towards the calculation of reinforced concrete cross-sections through the theory of limit states, formally introduced in our "Regulations for technical standards for concrete and reinforced concrete" that is PBAB/87. The Eurocodes, as new valid design standards in North Macedonia, bring with them the experiences and practice from European countries whose old standards have been incorporated into the new Eurocodes. Most of those experiences due to the same principle of calculating the reinforced concrete cross-sections that is according to the theory of limit states, are the same or quite similar to ours. However, due to the majority of countries that have adopted the Eurocodes, they must offer flexibility and adaptability in order to cover the wide spectrum of experiences from all over Europe. Consequently, if we focus only on the calculations of the reinforced concrete cross-sections, immediately noticeable are the three different models of the computational working diagrams of concrete, as well as two possible models of the computational working diagrams of the reinforcing steel. Where as a newability that has never existed in our practice are the unlimited strains in reinforcing steel according to one diagram, i.e the strains limited to a high value according to the second diagram. In this paper, a comparative analysis is made of the various methods of calculating reinforced concrete cross-sections according to our and new standards. More specifically, the differences in the calculations of cross-sections according to PBAB/87 and Eurocode 2 using the same working diagram were explored. The difference when using the parable-line diagram with the rectangular working diagram according to Eurocode 2, as well as the difference when using the working diagram of reinforcement with and without steel hardening, is also analyzed.