Precast bridge construction with UHPFRC—Shear tests and railway bridge pilot application

Due to the favorable material properties, Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) opens up new potential for precast options in PC bridge construction. On that matter, this article outlines the application, the load-bearing behavior and advantages of two different possibilities: slender prestressed bridge girders and a prestressed trough-shaped bridge element. Prestressed bridge girders made of UHPFRC allow for the realization of very slender cross-sections with thin webs. For these beams, the shear capacity is the governing design issue. Hence, further investigations on the shear behavior with a variation of the fiber content, the prestressing level as well as the amount of shear reinforcement were undertaken. In this context, also size effects were examined using specimens with different construction heights up to 1.0 m. To enable testing of a high number of specimens with realistic cross-sectional dimensions and at reasonable effort, an innovative experimental setup was developed and used for the investigations. Apart from these laboratory tests the present article deals with the pilot application of a railway bridge made of UHPFRC in Germany. The design and construction process as well as measurement results of the load and deformation behavior of the prestressed precast bridge element are presented and discussed.