Abstract：Fourteen axially restrained steel reinforced concrete (SRC) columns subjected to non-uniform fires, including one-face, adjacent-two-face, opposite- two-face, three-face and four-face fires, were experimentally tested to study the temperature field and mechanical behaviors of SRC columns. The influence of parameters such as fire condition, fire load ratio, load eccentricity ratio and restrained stiffness ratio on axial force and deformation of SRC columns in fire was analyzed. The tests results show that the fire conditions have obvious influence on the temperature distribution. With the same heating time, the highest temperature in the same sectional position of various columns decreases in turns from four-face, three-face, two-face to one-face fire condition. Temperature of the point in outer of steel flange is a little higher than that in outer of steel web for the same distance from the surface of specimens. The fire condition, fire load ratio, load eccentricity ratio, restrained stiffness ratio all have significant influence on the behavior of SRC columns during the whole heating and cooling process. The expansion in heating process and the shrinkage in cooling process of specimens increase with the number of heating faces exposed to fire. The axial expansion decreases with the fire load ratio, and increase with the load eccentricity ratio. With larger fire load ratio, specimens experience shorter time from the state of axial tension to axial compression and have higher degree of compression. A coefficient is introduced in this paper to define the ratio of axial force measured in the process of heating and cooling and applied to specimens at the initial loading. In the late period of heating and cooling process, the coefficient decreases in turns from four-face, three-face, two-face to one-face fire conditions, and the maximal value of coefficient increases with the load eccentricity ratio and restrained stiffness ratio, and decreases with the fire load ratio.
