Mechanical response of local rapid cooling by spray water on constrained steel frame structure at high temperature in fire

Abstract

Abstract. Locally rapid cooling of spray water had strong impact on high temperature steel structure. When temperature of beam reached 600 and cooling rate was more than 20 /s, the maximum axial tension could reach more than 5 times of the originally compressive force. The compressive bending moment at joint of beam-to-column changed to tensile bending moment, and the maximum bending moment could reach above 4 times as that when heated. After rapid cooling by spray water, deflection at mid-span increased slightly.