Compressive and bending test of assembled UHPC hollow pier using internal delayed casted composite connection
To promote the application of ultra-high-performance concrete(UHPC)in bridges and improve the construction efficiency of prefabricated bridge piers,this article proposes an in-cast composite connection for prefabricated UHPC hollow piers.Its main feature is to combine prefabricated UHPC hollow piers with the overlapping structure of the cap is transferred to the inside of the hollow pier,and the pier wall is used as a template for the internal post-cast UHPC material,which eliminates the formwork work at the construction site.The post-cast part does not appear on the surface of the pier body,improving the appearance of the pier.quality.To explore the load-bearing capacity of the assembled UHPC hollow pier,this article designed and produced three model specimens to study its load-bearing capacity,damage failure mode,etc.under bending deformation.Tests have shown that the cast-in composite connection can connect prefabricated UHPC hollow piers and caps effectively.However,achieving the same strength structure as the cast-in-place piers requires careful design of the location and bearing capacity of the shear connectors.Based on the test results,this paper developed a numerical model of the prefabricated UHPC hollow pier,and the calculation results are consistent with the tests.Based on numerical modeling methods,the structural behavior of cast-in-place composite connections in full-scale UHPC hollow piers was studied,and a design method for cast-in-place composite connections that could achieve the equivalent strength as cast-in-place piers was proposed.