Full-Scale Model Test of Prestressed Segmental Precast Continuous Girder Bridge

The precast segmental structure allows factory prefabrication and mechanical assembling, and thus is suitable for fast industrialized construction. Furthermore, it can effectively enhance construction efficiency and is also favorable for quality control. Although precast segmental concrete girder bridges have some applications in China, they are post-tensioned with both external and internal tendons. For this type of bridges, corrosion may occur at the joints of the internal tendons due to the reduction of durability of joints, which will decrease the overall durability of the structure. To overcome this limitation, a precast segmental structure that is all externally post-tensioned is developed, and for the first time applied in engineering practice at continuous girder bridges of the second Wuhu Yangtze River Bridge with light thin-walled structures of uniform section. In order to investigate the mechanical performance and force bearing mechanism of this new type of structure, a full-scale model test is conducted based on a 5 x 40 m prototype. The mechanical performance of this structure at servicing stage is evaluated through loading tests considering the most unfavorable conditions that may happen at the main sections. Besides, experiments are carried out to determine the ultimate bearing capacity at the mid-span section of the segmental continuous beam that is all externally post-tensioned, and the structural response and failure process of the main girder, joints and external tendons at the ultimate limit state are explored.