A Study of Fire Resistance According to Boundary Condition of Ordinary Grade Structural Steels

Building construction has been developed with an increase of steel application at main members, but the weakness should be resolved with a proper fire resistance. The fire engineering method is regarded as an alternative way to evaluate the fire resistance with mechanical and thermal properties at high temperature. In this paper, the fire resistance of H-section built with ordinary grade structural steels such as SS 400 and SM 490 those are representative structural steels at the construction market were analyzed by the difference of boundary conditions. The study showed that the H-section made of SM 490 represented little difference in reduction ratio of an allowable stress at one hour standard fire curve. And the hinge to hinge boundary condition from both H-sections was the lowest. As the grade of structural steel rises, the difference in an allowable stress at high temperature according to grade of structural steels is inclined to increase.