Stress Assessment of the Column-Superstructure Joint in a Reinforced Concrete Frame Bridge Under Creep and Shrinkage Deformations

To evaluate the impact of long-term deformations caused by concrete creep and shrinkage on the stress-strain state of the rigid column-superstructure joint in a frame bridge. To verify the applicability of modern creep and shrinkage models for this type of structure. Methods: The numerical modelling was performed using the Finite Element Method (FEM) in the Midas Civil software. Nonlinear long-term eff of concrete creep and shrinkage, as well as prestress losses in the reinforcement, were considered. Results: It was established that concrete shrinkage exerts the most signifi infl on longitudinal deformations and on forces in the joints during the early service stage. Concrete creep partially compensates for the stresses induced by shrinkage. The most signifi changes in forces occur within the fi year of service; thereafter, the rate of change decreases substantially. The research results have confi the necessity of accurately accounting for long-term deformations in design. Practical signifi The presented results will enable a more accurate prediction of the rigid column-superstructure joint behavior in frame bridges, thereby reducing the risk of crack formation and elevated residual stresses. This will contribute to enhanced reliability and durability of bridge structures.