Numerical studies on HSC-filled steel columns exposed to fire

In recent years, the use of Hollow Structural Section (HSS) steel columns filled with high strength concrete (HSC) is becoming more popular due to numerous advantages they offer over traditional columns. Apart from the aesthetic point of view, this composite system offers structural advantages. The concrete filling improves the load-bearing capacity at ambient temperature and can significantly enhance the fire endurance of the column. However, while the design rules for steel columns filled with normal strength concrete (NSC) are well established, there are many uncertainties for the filling with HSC. Thus, a numerical study is performed using the computer program 'BoFIRE' to investigate the behavior of HSS steel columns filled with HSC at both room and elevated temperatures. The test variables included column slendemess, load eccentricities, concrete compressive strength and cross-sectional shape.