FIRE RESISTANCE OF REINFORCED CONCRETE COLUMNS WITH +-SHAPED CROSS SECTION

The influence of several parameters, such as load ratio, effective column length, section dimensions, load eccentricity ratio, reinforcement ratio and load angle, on the fire resistance of reinforced concrete column with +-shaped cross section and exposed to the ISO834 standard fire, is analyzed. 1080 columns with +-shaped cross section and subjected to fire on all sides were selected for fire response analysis. Different load ratios, effective column lengths, dimensions of cross section, load eccentricity ratios and reinforcement ratios are considered in the analysis. Based on the simulation results, a practical calculation method for the fire resistance of columns with +-shaped cross section and subjected to fire on all sides is given in this paper. Simulation results show that: (a) load angle has little influence on the fire resistance of column with +-shaped cross section; and (b) reducing load ratio is an effective measure to improve the fire resistance of column with +-shaped cross section.