Modifikation des DIN-Fachberichtes 104 hinsichtlich der Berechnung des Langzeit-Tension Stiffening

By calculation of the bending stiffness of a composite bridge girder the tension stiffening is taken into account within the length of the concrete plate cracked. The determination of the realistic stiffness distribution is significant for the calculation of the field deflection under dead load and the stress-free workshop shape, respectively. The existing formulae of the DIN Fachbericht 104 [1] at the design of tension stiffening contain the approaches of the technical literature, e. g. [2], [3], which do not allow for the long term effects. In this report an analytical approach for the design of the long term tension stiffening is introduced, derived in [4]. A calculation example of a 3-span continuous girder bridge shows the application of the formulae in practice.