I recently traveled to Leipzig, Germany to present a paper at the 4th International Conference on Concrete Repair, Rehabilitation and Retrofitting. The research I presented was the result of the project I worked on during Summer 2014 in Delft, where we had a small research project to come up with an improved formulation for concrete under fatigue for the Dutch National Annex to Eurocode 2-2.
The abstract of the paper is as follows:
Understanding the behavior of concrete in fatigue is essential for understanding the behavior of concrete bridges subjected to repeated loads. The Dutch National Annex to the Eurocode prescribes a different expression for the Wöhler curve for compression fatigue than the Eurocode itself, and does not have a smooth transition for 106 load cycles. A new expression for concrete in compression fatigue is thus necessary. This new expression should be valid, yet not overly conservative, for high strength concrete. Therefore, a database of experiments on (ultra) high strength concrete tested in compressive fatigue is used to validate the new proposal. A proposal for the assessment of the fatigue strength of existing structures is prepared. For design, a simplified method is proposed. An expression for the fatigue strength of concrete under compression, suitable for high strength concrete, is now available, which can replace the previous fatigue expressions used in The Netherlands.
The presentation I gave is shown here: