Experimental Study On The Seismic Behavior Of Earthquake-Resilient Prefabricated Composite Columns

It has become a significant research focus for structures to achieve the function of rapid rapair after earthquake in the building industrialization filed. An innovative earthquake-resilient prefabricated composite columns, which include the replaceable energy-dissipation parts and the RC columnial segment, was proposed for prefabricated RCS bottom columns which might be more prone to get damaged during strong earthquakes. The replacing measures and the seismic performance of the innovative composite column was experimentally studied.A poured RC column and eight full sized composite columns were tested under low cyclic loading to investigate the influence of the details of axial load ratio, area of the replaceable steel plate, the padding lump’s material and the contact setting method on the seismic performance of the specimens. The results showed that:(1) The damage of the composite column concentrated in the replaceable energy-dissipation parts with the RC columnial segment keep in elastic state before the replacement. In the late loading after the replacement, the replaceable steel plates got seriously buckling damage while the RC columnial segment was damaged lightly and the longitudinal reinforcement was also just light yielded. The expected failure mode was achieved;(2) Compared with the poured RC column, the composite columns has considerable bearing capacity, energy dissipation capacity, and initial stiffness,meanwhile the composite columns showed well ductility. That indicated that the composite column has a good mechanical perform with rational constructions.(3) The load and deformation capacity of the composite columns replaced after damaged were almost at the same level as the corresponding specimens before 1/50 story drift.(4) The bearing capacity and energy dissipation capacity of the composite columns increase as the axial compression ratio increases. But the damage of the replaceable energy-dissipation parts at the column bottom was increasing.(5) Compared with the brittle behavior of the high strength grouting material, the UHTCC performed good compressive ductility and plastic deformation capacity. It can lighten specimens’ damage and is good for the hysteretic behavior stability and the energy dissipation.Nonlinear numerical simulation under monotonic loading on the composite column was carried out by ABAQUS program, showing good agreement with the test results, and the established finite element analytical model can accurately predict the mechanical behavior of the composite columns. The influences of axial compression ratio and strength of the replaceable steel plate to the skeleton curves of the composite columns were studied by numerical calculation.