Nonlinear structural analysis as an assessment tool for existing concrete structures

This paper gives an overview what the impact of nonlinear analysis can have on the remaining capacity of an existing concrete structure. Today and in the past a concrete structure is designed on the level of a linear analysis. The layout of the reinforcement is mostly designed on a cross sectional base, where quasi nonlinear behaviour on the cross-section is included. Also in the past some phenomena, like shear force behaviour, were neglected in design recommendations. The shift to a full nonlinear analysis is a great step, so after more than 20 years of improvement of concrete material models and improvement of CPU, in 2007 a decision has been made to setup a workshop around shear force behaviour related to nonlinear analysis. The result of this workshop was to setup a Nonlinear guideline for concrete structures for the framework of the re- examination of existing concrete structures. In 2010 the Model Code 2010 was published with safety formats to extend the checks of concrete structures, re-examinated by nonlinear analysis. The first draft of Nonlinear guideline was published in 2012, reason to setup a second workshop to get a better dissemination under the concrete analysis.