Post-Earthquake Fire Resistance of Ductile Concrete Filled Double-Skin Tube Columns

AbstractExperimental studies were conducted to examine the behavior of concrete-filled double-skin tube (CFDST) columns exposed to fire after being subjected to simulated seismic loads. The experiments were conducted in two separate phases, consisting of (1) the quasi-static cyclic tests, followed by (2) fire tests. Three nominally identical column specimens were constructed for these studies. One of the specimens was directly tested under fire to quantify its resistance in an undamaged condition. The other two specimens were first subjected to quasi-static cyclic lateral loads, imposing varying degrees of lateral drift to simulate two different seismic events with moderate and high damage levels before being exposed to fire. Both of the specimens were pushed to the maximum drift of 6–6.5% with different residual drifts of 1.4 and 3.9% for moderate and high damage levels, respectively. The undamaged and damaged columns were then subjected to the same fire tests in accordance with a standard temperature-ti...