MECHANICAL PROPERTIES OF STEELS FOR BRIDGE HIGH PERFORMANCE STRUCTURE SUBJECTED TO HEATING AND COOLING PROCESS SIMULATING FIRE

Abstract

For investigating effect of heating and cooling process simulating fire on mechanical properties of Steels for Bridge High Performance Structure (SBHS), a series of experiment was carried out. The heating of 600℃ did not change the mechanical properties of SBHS from those without heating and cooling. The heating of 900℃ and air cooling decreased the mechanical properties of SBHS due to softening. The heating of 900℃ and water cooling increased the ultimate strength due to hardening; however, it decreased the yield stress and elongation of SBHS to the level below that required by JIS.