Abstract:

Simplifying the joint structure of precast beams so as to facilitate industrial construction has become a hot spot in the research of precast and assembled bridges． Using ultra-high performance concrete ( UHPC) can greatly simplify the joint structure and provide a new solution for rapid construction． In this paper，experimental research on bridge deck joints was carried out． Pull-out tests were designed to simulate the interaction of UHPC and common steel bars in bridge deck． Bending tests on plate joint specimens based on actual engineering projects were also conducted． Based on finite element numerical simulation and theoretical stress analysis，the influence and effecting mechanism of factors，such as embedded length of steel bars，thickness of protective layer，transverse spacing of steel bars，diameter of steel bars ( d) and interface form，on the mechanical properties of UHPC joints were studied． Finally，the recommended values of parameters for UHPC joint design of bridge deck were given． That is， rough diamond interface should be used and the thickness of protective layer should be no less than 2d and the embedding length should be no less than 8d．

Key words: ultra-high performance concrete, precast structure, joint of bridge deck, pull-out test, test on slab specimen, finite element analysis