The design of bonded reinforcement for thermal stresses in prestressed concrete reactor vessels

This paper deals with examples of thermal loadings where instationary growth of tensile zones and redistribution of stresses by cracking are of importance. Temperatures produce, in addition to prestressing and internal pressure, the most important stresses in a prestressed concrete reactor pressure vessel. Characteristic of thermal stresses is that they are influenced to a large extent by creep of concrete and that they influence stress redistributions by temperature dependent creep data. The discussed stress states with tensile stress states produced by temperature changes and creep redistribution due to temperature dependent creep show that calculations performed for stationary states without taking into account cracking of the concrete are generally very conservative for the design of the reinforcement. (Auth.)