Experimental study on post-fire properties of steel wires of bridge suspender

Abstract This paper presents an experimental study on the post-fire static and fatigue properties of steel wires, which is the basic component of bridge suspender. In these tests, the effect of exposure temperatures, duration of heating time, cooling methods and prestress in steel wires during heating process was investigated. It is observed that the residual strengths (including static and fatigue strengths) of steel wire specimens were highly related to the maximum temperature reached during the heating process, and when the maximum temperature exceeds 400 °C, more significant reduction in residual strengths could be caused by higher maximum temperature. By analyzing the residual strength of the specimens applied with different prestresses, it is found that the prestress has an adverse effect on the residual strength. In addition, through electron microscope scanning, the mechanism of the material degradation under fire attack was analyzed and discussed. The findings of this study can be used to evaluate the extent of damage due to fire attack and provide guidance for maintenance or repair strategy.