Study on the Deformation Behaviour of Reinforced Concrete Beam-Supporting Column Transfer Structures during Fire Exposure

Considering that reinforced concrete beam-supporting column transfer structures are often large, it is difficult to perform experimental research on the whole structure. Therefore, in this paper, the key part of the transfer structure, namely, the beam-supporting column joint, is tested at high temperatures. These test results are verified through finite element analyses. The research object used in the finite element analyses is extended to the overall structure. The results of this research show that under symmetrical fire conditions, the overall deformation mode of the beam-supporting column transfer structure is symmetrical about the central axis of the structure. The deflection of the transfer girder and the corresponding beam segments of the upper beams increased to different degrees. The frame column produces bending deformation towards the outside of the frame, and the greatest deformation generally occurs in the fire floor. Under asymmetrical fire conditions, the overall deformation of the beam-supporting column transfer structure is asymmetrical about the central axis of the structure. The entire structure has a tendency to slope towards the side of the fire room. The deflection curve of the beams protrudes to the side of the fire room. This phenomenon is more obvious below the fire floor, whereas the deflection gradually declines from the lower floors to the upper floors.