The theoretical model for axially loaded recycled aggregate concrete（RAC）filled steel tube（RACFST）stub columns after exposure to high temperature is developed on the basis of the finite element software ABAQUS

in which

the effects of the recycled concrete aggregate replacement ratio and the maximum temperature suffered are considered in the stress versus strain relationship of RAC.The theoretical model is used to predict the failure pattern

load versus deformation relationship

bearing capacity and composite elastic modulus of axially loaded RACFST stub columns after exposure to high temperature

and the predicted results generally agree well with the test results.The complete load versus deformation relationship of axially loaded RACFST stub columns after exposure to high temperature is analyzed using the finite element model

and the analytical results reveal the stress versus strain relationship of steel and RAC at several positions and the interaction stress between steel tube and core RAC under loading procedure.The achievements in this paper may be referenced by the related practice and code development of RACFST structures.