Mechanical Properties of High Strength Steel S690 at Elevated Temperatures

Abstract:

Under fire conditions, the load bearing capacity of steel structures reduces mainly due to the deterioration of its mechanical properties. In this paper, an experimental investigation was conducted, using both steady state and transient state methods. The comparison of test results with European, American, Australian, British and Chinese design standards of steel structures shows that fireresistance design of steel structures with S690 is unsafe according to the current design standards. Based on the reduction factors of the elastic modulus, and the yield strength and the ultimate strength of S690 obtained from this study, some specified predictive equations were proposed to describe the deterioration of mechanical properties of S690 at elevated temperatures. The predictive equations can be employed for practical fireresistance design of steel structures with members made of S690, providing reference for the revision of current worldwide leading design standards.