A Innovative Longitudinal Prestressed Continuous Ultra-high Performance Concrete Box-girder Bridge

摘要

A new box-girder bridge structure is proposed based on the superior mechanical properties of thernultra high performance concrete (UHPC). The proposed structure is the combination of UHPC andrnthin-wall box girder with densely distributed diaphragm plates, which can simplify the conventionalrnthree-direction prestressed structure into unidirectional (longitudinal) prestressed structure.rnCompared to the traditional concrete continuous box-girder bridge, the superstructure weight of thernnew bridge structure can be lightened by 50~60%. A trial design and some experimental studiesrnwere conducted to study the proposed bridge structure. Results of UHPC beam creep deformationrntest demonstrated that the creep deformation of the UHPC beam was about 1/5 that of ordinaryrnconcrete beam. Results of the UHPC box-girder model test indicated that the post-cracking shearrnperformance of the box-girder could be improved by setting diaphragms.