Mechanical and thermal properties of SM 490 at high temperature for fire engineering design

Abstract

The use of structural steels is rapidly increasing in the high-rise building market in Korea because of its higher quality, construction period, and lower cost than the ordinary construction materials such as concrete. However, steel structures have a serious drawback. Severe fire conditions tend to weaken them and they can collapse. To overcome this weakness, steel structures must meet the fire resistance requirements in the building laws or building codes of the respective country. In Korea, the method for evaluating fire resistance in steel structures is currently being developed with performance based engineering. Fire engineering offers calculation methods for evaluating fire resistance. The calculation depends on the accurate mechanical and thermal data of the materials at high temperature. The purpose of this paper consists of two parts: one is to obtain data on mechanical properties at high temperature and to gather thermal data, and the other is to compare the calculation with an experimental fire test. By using the results of tensile strength tests conducted at high temperature, the regressive equation for yield strength and elastic modulus of structural steel were derived. Increasing patterns of temperature from cold to high were very similar between the results of analysis and those of fire tests. This similarity held until the half of fire resistance was obtained.