Experimental study on seismic performance of UHPC post-casting assembled joints
Based on the research of the shear wall-frame structural system,this paper proposed a connection method in which UHPC was applied to the material of the post-cast joints of precast elements and the lap length of the steel bars was reduced.Low-cycle reserved load tests were carried out to explore the seismic performance of the proposed connection joints(one beam-column joint,one wall-beam joint,and two column-foundation joints).The research results showed that the failure form of the proposed beam-column joint was the concrete at the base of the beam crushed and the crack width at the laminated interface between the precast beam and column was excessive.The overall energy consumption capacity of the joint is good,in line with the requirements of"strong column and weak beam,strong node and weak member".Besides,the bond-slip damage occurs in the beam-wall joint and the energy dissipation capacity is poor.For the column-foundation connection joints,the positive and negative peak loads for joints with UHPC as the connecting material are 26.5%and 15.6%higher,respectively,than for cast-in-place specimens,and the former have higher stiffness,with ductility factors above 4 for both.Most importantly,the use of UHPC can reduce the hoop ratio in the joint area,thus reducing the hoop density in the joint area.The finite element model is validated based on the test results,and the finite element analysis results show that the load-bearing capacity no longer changes with the lap length when the lap length of the specimen exceeded 14d.Above all,the proposed connection method can significantly reduce the anchorage length of steel bars,and with the excellent mechanical properties of UHPC,the seismic performance is basically equivalent to that of cast-in-place,which has a certain engineering application prospect.
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维普
