Energiebasierte direkte Berechnung der Bewehrung zur Rissbreitenbegrenzung

Energy-based direct calculation of reinforcement for crack width control. In the literature and in many standards, crack spacing and mean strains are used to predict crack widths. To calculate the crack spacing, the average bond stress must be known. In many calculation approaches, this is simplified and assumed to be a constant value. Based on a realistic approximation of the slip curve s(x) over the length, Tue and König have shown how the mean bond stress can be determined depending on the crack width in order to improve crack width calculation. This paper describes an energy-based approach that can be used to directly determine the reinforcement for the control of crack widths for any given relationship between local bond stress and slip (bond law). The approach is applied to the well-known bond law with power approach and examined for agreement with experimental results. Although mean strains, crack spacing and mean bond stress do not appear explicitly in the formulas, the solution is mathematically exact within the underlying relationship of local bond stress and slip.