UHPC Through-Girder System for Shallow Bridge Structures

Shallow structures are often required in highway bridges when an underneath clearance is critical. Use of shallow bridges allows to avoiding a more expensive bridge system such as arch or truss bridges. Through-girder bridges are categorized as one type of girder bridges and are more receptive to the majority of the contractors as compared to other sophisticated bridge systems. When conventional concrete is used in through-girder bridges, relatively large and heavy edge girders are necessary because they need to carry all dead and live loads. Recent advancement of ultra-high performance concrete (UHPC) allows to leveraging this exceptional material in various types of structures and results in increased structural capability and performance. The use of UHPC in shallow bridges can reduce the sizes of the structural members or increase the span capacity. This paper addresses a through-girder system that involves the use of UHPC in primary members and connections. It describes various components of a through-girder system, including the transverse beams, edge girders, and longitudinal and transverse connections. A numerical example is presented to demonstrate the analysis and design of a through-girder bridge. Both high-performance concrete (HPC) and UHPC options are described for comparison purpose. A UHPC through-girder system is expected to facilitate bridge construction due to the reduced girder weight and simplified prestressing and reinforcing details. It also allows to enhancing the structural performance and increasing the service life of the bridges.