Rheological concrete creep prediction model for prestressed concrete bridges constructed by the free cantilever method

The primary objective of this study is to construct a simpler and more reasonable rheological model than existing models for predicting the creep phenomenon of concrete. Deformations of concrete under sustained stress can be expressed by the sum of immediate elastic deformation, time-dependent and time-independent short-term creep, and long-term creep, according to the mechanism and time-dependency. To simulate these deformations, a rheological model with six parameters was constructed. In composing each parameter, the microprestress-solidificationtheory and existing design codes were used. Moreover, the numerical approach was also used for the specific parameters that cannot be deduced from existing theory and design specifications. Finally, actual test data from prestressed concrete bridges built using the free cantilever method were analysed for verification of the proposed model and the suitability of the model was confirmed by comparisons with existing prediction models and design codes.