Fire Resistance Of Steel Reinforced Concrete (SRC) Columns Subjected To Small Eccentric Load And 3-Side Fire Exposure

Steel reinforced concrete (SRC) columns are extensively used in multi-storey and high-rise structures for their advantages of high load carrying capacity, big stiffness and excellent earthquake resistance qualities. As an important load bearing structural element, the fire resistance of column has significant impact in a whole structure. Recently, researches of fire resistance with SRC columns lay particular stress on columns subjected to 4-side fire exposure. In fact, columns may be faced with different modes of fire action. Based on this, Experimental research and finite element analysis are carried on SRC columns subjected to 3-side fire.The main contents including:(1) Fire resistance tests on two steel reinforced SRC columns subjected to 3-side standard fire exposure were conducted. Axial deformation and lateral displacement at middle height were observed, as well as the concrete spalling and damage procedure of the columns.(2) The thermal properties, mechanical performances of steel and concrete under high temperature are summarized and analyzed. Then a three-dimensional nonlinear finite element model was established by using ABAQUS to analyze the behavior of SRC columns under 3-side heating, which shows reasonable agreement with the test results.(3) Parameters were studied to investigate their influences on fire resistance of SRC columns under 3-side heating, including the influences of load ratio,eccentricity,dimension of cross-section,steel ratio,longitudinal bar ratio on fire resistance of SRC columns. The result shows: load ratio,eccentricity and dimension of cross-section are the main impact parameters.(4) On the basis of numerous parameter analysis, giving a simplified way to determine the fire resistance of SRC columns under 3-side heating, which may give a reference to engineering applications.