Experimental study on the seismic performance of earthquake-resilient prefabricated composite columns

A new prefabricated composite column with replaceable components was developed to avoid the severe damage on the column base in reinforced concrete-steel (RCS) hybrid frame structures, in order to meet the urgent need of structural resilience after earthquake damage. Eight full-scaled prefabricated RC columns were tested under low-frequency cyclic loading to investigate the influence of the cross-sectional area of external replaceable steel damper, the axial compression ratio and the material of padding block on the seismic performance of the composite columns. The expected failure mode was observed, which the damages were mainly concentrate on the replaceable components at the lower part of column and the upper part with unreplaceable components was still in the elastic state. Furthermore, the composite columns before and after replacement of damaged components experiencing 1/50 drift exhibit basically similar energy dissipation and load-carrying capacity. By reducing cross-sectional area of replaceable steel plate, the load-carrying capacity of the specimen may also be reduced. The moment carrying capacity and energy dissipation capacity of specimens increases with the design axial compression ratio increasing from 0.3 to 0.5. The research results can provide reference for the practical application and further research of resilient columns. © 2020, Editorial Office of China Civil Engineering Journal. All right reserved.