Residual Strength of L-shaped Steel Reinforced Concrete Columns after Exposure to High Temperatures

The mechanical behavior of L-shaped steel reinforced concrete (SRC) columns after exposure to high temperatures is investigated by conducting experiments on eight column specimens. The specimens are first heated to a target temperature and are loaded to failure after cooling down to room temperature. The effect of heating duration, loading eccentricities, and loading angles on the temperature distribution, failure mode and residual bearing capacity of the columns is studied. The test results show that L-shaped SRC columns under axial and eccentric loading have a post-high temperature shear and bending failure mode, respectively. The residual bearing capacity of the specimens decreases significantly (up to 1/3) compared to that at room temperature. The residual bearing capacity of L-shaped SRC columns is governed by loading eccentricities, and an eccentricity of 80 mm (0.36) leads to a reduction in residual capacity by 47% of its ambient value. The loading angle has an obvious effect on the damage range of L-shaped SRC columns. A formula for calculating the residual bearing capacity of L-shaped SRC columns under biaxially eccentric compression is proposed and validated against test results.