Experimental and simulation study on seismic performance of steel‐PVA hybrid fiber cementitious composites‐encased CFST

Abstract

Six hybrid steel and PVA fiber cementitious composite (S&PFCC)‐encased concrete‐filled steel tube (CFST) columns were designed and fabricated, and the effects of axial compression ratio, core concrete strength grade and steel tube thickness on the seismic performance of composite columns were studied. The test results show that the increase of core concrete strength can obviously improve the bearing capacity and energy dissipation capacity of composite column and can restrain the strain growth rate of steel tube after yielding. Low axial compression ratio and thicker steel tube thickness can improve the overall seismic performance of composite columns. Three calculation methods are modified, and the modified An method can predict the lateral bearing capacity of composite column well. Finally, based on the OpenSees finite element software, the seismic performance of the CFST column wrapped in S&PFCC is simulated to verify the test, and the numerical study shows that the seismic performance of the composite column can be optimized by increasing the steel fiber content, while PVA fiber has a weak effect in the elastic stage, and can effectively improve the ductility of the composite column in the plastic stage.