Creep and fatigue analysis of reinforced concrete structures

A computional procedure for the creep and fatigue analysis of reinforced concrete structures exposed to flexure is presented. The fatigue loading effects are modified into an equivalent creep analysis. The analysis is based on the finite element method employing beam elements. The material behavior of steel, concrete and bond between reinforcement and concrete are described as realisticly as possible. For the reinforcing steel the stress-strain behavior as measured in tests or given in codes is assumed. For the stress-strain behavior of concrete in compression under static loading, the proposal by Park/Pauley is taken. The influence of sustained or fatigue loading is taken into account by using the isochrone σ-ε-relationship valid for t > t o or N > 1 respectively; whereby the creep coefficients for both type of loadings are taken from MC90. For sustained and fatigue loading the isochrone bond stressslip relationship is used. The creep coefficients are taken from MC90. The accuracy of the proposed model is checked by comparing the behavior of some test beams under sustained and fatigue loading with the predictions