Fire Resistance of Fire‐Resistant Steel Columns

Abstract

This paper is to verify the fire resistance of columns made from fire‐resistant (FR) structural steel by means of a full‐scale loaded heat test and numerical analysis. Because of the elements contained, FR steel has higher strength than conventional structural steel at elevated temperatures. Its 0.2% proof stress at 600°C is equal to or greater than two‐thirds the value specified at room temperature. Rock wool, ceramic fire protection, and foaming‐type intumescent coating were used as fire‐protection materials. Using Japanese codes, the high‐temperature strength of steel can be exhibited with building members, the fire‐protection thickness can be reduced below what is required for conventional steel columns, and 1‐h fire resistance can be obtained by intumescent coating with a lower insulation property. Also, deformation and fire‐resistance time can be simulated from the mechanical properties at elevated temperatures and elastoplastic thermal deformation analysis. Furthermore, this study is based on Japanese codes, and results will differ if based on ASTM codes.