Justification of proposed changes in the crack width calculation methods of EN 1992-1-1 and MC 2020 скачать в хорошем качестве

Justification of proposed changes in the crack width calculation methods of EN 1992-1-1 and MC 2020

This presentation focuses on the reasons which justify the need to update the crack width models of both EN 1992-1-1:2020 and MC 2010. Consideration is given to the need to account for the effect of cover because, even though the experimental evidence of its effect is overwhelming, and the physical reasons for its influence are clear, there are still opinions that oppose its inclusion. It is shown that there are significant differences in the cracking behaviour of tensile and flexural elements that are not accounted for in current models, which are based on a tie model. The main differences have to do with the different distribution of stresses prior to cracking and with the effect of curvature. It is also shown that there is a need to modify the definition of the effective area because the current definition leads to absurd results. Accounting for these factors results in significant improvement in the agreement with experimental data. Furthermore, the effect of casting position is also shown to have a significant influence on cracking behaviour. Finally, it is argued that shrinkage effects on cracking can be ignored. Prof Alejandro Pérez Caldentey earned his Master’s Degree in Civil Engineering from the Technical University of Madrid (UPM) in 1989 and his PhD from the same University in 1996. He has extensive experience in structural design having worked since 1989 at FHECOR Consulting Engineers. Among the structures he has worked on are the Burguillo concrete arch bridge, the Sil River Viaduct, or the widening of the Los Santos Bridge. He holds engineering licenses in Chile, where he is EOR for the Yalquincha bridge, and in 3 States of the USA and in 3 Canadian Provinces, where he was worked on the construction of the Champlain bridge or the CAT III Check of the Patullo Bridge.  In parallel he is a part-time Professor at the Technical University of Madrid since 1992 where he has carried out extensive research on such topics as time-dependent behavior of concrete structures, shear, punching, cracking, deflections, as well as blast resistance and robustness. He was member of CEN-TC250/SC2 Project Team for the general text of pr EN 1992-1-1. He is also member of fib TG 2.1, responsible for serviceability design for MC 2010 and its revision MC 2020.