Comparison of Steel and Reinforced Concrete Frames' Durability under Fire and Post-Earthquake Fire Scenario

Two fire accidents took place in the Plasco Tower in Iran and Grenfell Tower of London in 2017. Although both of them have led to human tragedies, post-earthquake fire can cause more irreparable damages and catastrophes in larger extents. Engineering structures are subjected to different loads during their lifetime, which may cause damage or secondary loading effects. Evaluation of durability and stability of fired structures and the effects of seismic loading are considered to be significant parameters in fire engineering. The aim of this study is to evaluate and compare durability of reinforced concrete and steel frames during fire loading and post-earthquake fires. In this study, two 7-story steel and reinforced concrete frames are exposed to the fire load. At first, steel and concrete sections are put under various thermal loads in order to compare the method of their heat transfer. Then, the effects of crack on heat transfer of concrete sections are studied. Afterwards, the selected frames are exposed to the fire and post-earthquake fires. The results indicated that cracking and strength reduction due to seismic loading can decrease the durability of reinforced concrete frame in post-earthquake fire scenarios. However, the durability of steel frames has no significant relationship with the seismic loading and their durability are almost the same in the fire and post-earthquake fire scenarios.