At an international workshop on shear force capacities of concrete structural element, held in Rotterdam, the Netherlands in 2007, predictions of the ultimate limit state of three different girder experiments were presented. This workshop was initiated by the Dutch Ministry of Infrastructure and organized by TNO (Vervuurt & Leeghwater, 2008). The ultimate capacities, predicted by six teams using different nonlinear software packages, showed a large scatter. Also the predicted crack patterns showed a large scatter.
With this in mind, research on the development of a “guideline for nonlinear analysis of concrete girders” was started. The fib Model Code 1990 was the background document when Peter Feenstra started with the development of the guideline. Also, Joop den Uijl was involved in validating the guidelines. From 2010 the draft version of the fib Model Code 2010 was used as background document. Today, both the MC2010 and the Eurocode2 allow the use of nonlinear analysis to verify the design capacity of concrete objects.
The validation of the guidelines is done by simulating old and new experiments. To verify human and software factors, several people were involved in this project and two commercially available software packages were used. Finally the first version of the guideline was published in May 2012. It is used by the Dutch Ministry of Infrastructure and the Environment when commissioning engineering work for reexaminations of existing concrete structures in the Netherlands to reveal extra remaining structural capacity.
To verify whether the guideline is also valid for a larger group of international endusers and for other software packages, a prediction contest of T-shaped prestressed girders was set up in 2014. The tests were performed by Sebastiaan Ensink in the Stevin Laboratory of the Delft University of Technology. The participants of the contest gathered in a workshop in Parma. The outcome of this contest showed that the guidelines are indeed helpful for reducing model and human factors when predicting the behaviour of concrete structures by means of nonlinear finite element analysis.
As a result of additional validation studies and making use of the experiences of the workshop in Parma a new version of the guidelines has been published in 2016. The present document gives an overview of validations studies for this version of the guideline. Maciej Kraczla has contributed to this document.