Basic creep of concrete - Coupling between high stresses and elevated temperatures

The prestressed concrete confinement vessel is the third and last barrier in French Nuclear Power Plants (NPP). In case of a s vere accident (loss of cooling agent of the reactor for instance), pressure and temperature will increase in the nuclear vessel (+0,5 MPa and 180 °C during 2 weeks). Due to elevated temperatures, the evolution of basic creep will be accelerated. High compressive stresses would appear and induce higher delayed strains and damage. The modelling of basic creep and its couplings with temperature is then very important for the safety of the structure (tightness of the concrete vessel). Here, we present a model considering the following elements: a coupling between creep and damage is introduced, kinetics of basic creep is affected by temperature by the means of an Arrhenius thermo-activation, damage due to the increase in temperature (under stress or not) is taken into account. The model is compared with the available experimental results. This work is a part of the MACENA project