Research On Performance Of SRC Columns Subjected To Axial Compression In Fire

The behavior of the SRC columns subjected to axial load in fire has been analyzed through finite element program ABAQUS. The distributing circumstance of thermal field of SRC columns and its impact factors were researched in this thesis. In addition, the behavior of the axial loaded SRC columns in fire and the influence of parameters on fire-resistance of SRC columns has been analyzed. This paper is aimed at getting some guiding practical conclusions for fire resistance design of SRC structures and making it possible to study further the mechanical performance of SRC structures at high temperature.The analysis showed:The surface temperature of SRC column is far higher than the internal temperature in fire. The nearer to the surface of SRC column, the temperature gradient is bigger. More surfaces of SRC column exposed to fire, the temperature of the column is higher. The temperature of the surfaces exposed to fire is highest and the temperature of the unheated surfaces is lowest. Sectional dimensions and length-to-width ratio of the section are main factors affecting the temperature field of SRC columns. The temperature decreases with the increase of sectional dimensions and the temperature rises with the increase of length-to-width ratio of the section. With the lasting of the fire duration, the bearing capacity of SRC columns becomes weaker and compressive stresses becomes smaller when the column wrapped. It buckling at the middle of the column when the axial loaded SRC column wrapped at room temperature and it buckling at the ends of the column when the axial loaded SRC column wrapped in fire. The stresses of flange is smaller than the stresses of web. Sectional dimensions, length-to-width ratio of the section, steel ratio and the fire duration are main factors affecting the bearing capacity of SRC columns under fire. The bearing capacity becomes stronger with the increase of sectional dimensions as well as the steel ratio. The bearing capacity becomes weaker with the increase of length-to-width ratio of the section as well as the lasting of the fire duration.