| With fast economic development and rapid city growth, fire accidents may take place which results in building destruction and personal casualties. It is a topic of general interest that how the mechanic performance of the structure has changed after the building fire. Many investigations on the high temperature behavior of concrete have been reported and a lot of valuable research findings is received, which focused on the continual changes of structural temperature, deflection and interior force after exposure to fire. However, the effects of fire on building are rather complicated and still unsolved so far.In this paper, the following research works are done:(1) The relationship between compressive strength of concrete and the influence factors such as different temperature, different time and refrigeration mode is obtained based on the experiment of concrete block, and classification standards of fire is proposed.(2) The carbonation depth of concrete after high temperature is studied based on the experiment of concrete block, and the relationship between carbonation depth and the influence factors such as different temperature, different time and refrigeration mode is obtained, and the guidance to the assessment of the durability of concrete structures after fire is provided.(3) The residual load-carrying capacity of RC beams after high temperature is studied based on the experiment. The effects of influence factors to residual load-carrying capacity is researched, and the relationship and development law of temperature crack and load crack is summarized. In addition, applicability of the plane section assumption is verified.(4) The temperature field of different temperature condition is obtained based on ANSYS, a finite element analysis software. And the residual load-carrying capacity of RC beams after high temperature is calculated by equivalent cross-section reduced method, which is well coincided with the experimental results. |
PDF Full Text Request