Post-fire performance of very high strength steel S960

For the time being, high strength steels and very high strength steels have gained employment in some significant structural components of landmark constructions, where the strength can be fully utilized. However the available research on structural and material performance of high strength steels and very high strength steels is very limited in literature, especially for very high strength steels. The potential advantage and low research level of very high strength steels call for more researches. The steel members made of very high strength steels in constructions are sometimes inevitably exposed to fire hazards, after fire whether they are reusable or not, it needs a reliable evaluation. In order to reveal post-fire material performance of very high strength steel S960, an experimental study was carried out, which serves for the evaluation of post-fire performance of structures with components made of S960. Tensile tests were undertaken on specimens made of S960 after cooling down from temperatures up to 1000 °C. Its post-fire elastic modulus, yield strength, ultimate strength, and stress–strain curves were obtained. It is found that the post-fire performance of structural steels is dependent on steel grade. Some unique predictive equations were proposed for evaluating the mechanical properties of S960 after fire.

► Tensile tests were undertaken after cooling down from fire temperatures up to 1000 °C.
► Post-fire material performance of VHSS S960 was reported for the first time.
► Predictive equations were given for evaluating performance of S960 after fire.
► S960 can regain its property after cooling down from fire temperatures below 600 °C.
► It offers proof for safe evaluating and reuse of members made of S960 after fire.