Dependence of mechanical properties of high strength steel S690 on elevated temperatures

The deterioration of mechanical properties is predominant in the design of steel structures under fire condition, as it leads to associated reduction of load bearing capacity. To understand elevated temperature dependence of mechanical properties of high strength steel S690, an experimental investigation has been carried out, using both steady state and transient state methods at temperatures ranged from 20 °C to 700 °C. Comparison of results with European, American, Australian and British design standards shows no current standard can safely guide fire-resistance design of steel structures with S690. Therefore the mechanical properties of S690 at elevated temperatures obtained herein are of value.