Analysis of time-varying mechanical properties of prestressed concrete containment during the tensioning process and service considering the influence of creep

The containment structure is an important barrier that ensures the safe operation of nuclear power plants. Currently, most studies on concrete creep in containment structures assumed constant stresses in the calculation of creep, which is not consistent with realistic cases or circumstances. In this study, a combination of theoretical analysis and numerical simulation was used to investigate the prestressed concrete containment (PCC) of nuclear power plants. Based on the age-adjusted effective modulus method, three widely accepted concrete creep models were improved to obtain a variable stress creep model. Using the improved creep model, the effect of concrete creep on the PCC structure during prestressed tensioning and long-term service was systematically analyzed. Then, the internal pressure bearing capacity of the PCC in long-term service was assessed, and the effects of long-term concrete creep on the mechanical properties of the PCC were evaluated.