Full-scale investigation of post-tensioned prestressed concrete bridge girders subjected to frost heaving in cold regions

Frost heaving is one of the major diseases of post-tensioned prestressed concrete structures in cold regions. This study investigates the effects and underlying mechanisms of frost heaving damages on the mechanical behaviors of full-scale post-tensioned prestressed concrete girders of a highway bridge. Forensic investigations were performed for three bridge girders through destructive tests, which included borehole, anatomy, and flexural tests, with an intact girder as the control. Three-dimensional nonlinear finite element models of the girders were established to understand the mechanisms of the effect of frost heaving. The results show that frost heaving reduced the effective prestress, mechanical properties of concrete, and bond between concrete and tendon, thus reducing the crack resistance and durability of the girders. This study provides new insights into post-tensioned prestressed concrete girders under frost heaving. The results are useful to improve the safety, serviceability, and durability of prestressed concrete bridges in cold regions.