Numerical Approach to Assess the Performance of Concrete-Filled Steel Tube Stub Columns under Fire Hazards

Abstract

Concrete-filled steel tube (CFST) stub columns made of various steel thicknesses and concrete types subjected to combined thermomechanical load were investigated using the finite element (FE) program, and optimization of steel and concrete for economic options was studied. The relationships among fire-resistance rating (FRR), critical temperature, load ratio, concrete grade, and steel thickness were investigated in this study from an economic and structural perspective. The strength and FRR of stub CFST columns with the same external dimensions can be kept in close proximity using larger concrete infills and thinner outer steel tubes instead of thicker outer steel tubes with thinner concrete cores, to make construction economical. The civil construction industry is largely focused on safety and economics. Cost is a major factor in any investment by a large-sized real estate developer or private residence owner. CFST columns have many benefits due to their structural advantages, so they can be used for both residential and high-rise structures. Moreover, the results of this research show that CFST columns can be built without compromising cost, structural integrity, safety, and comparable FRR by optimizing the choice of steel thickness and concrete grade. This enables construction firms to maintain safety and strength while keeping costs within a reasonable range, so that expensive housing can be made more affordable.