Based On The Fire Resistance Test Of The Earthquake Damage Of The Concrete Frame Structure

In this paper, two monolayer concrete frames with the same as reinforcement KJ1 and KJ2 are designed . KJ1 is designed to simulate low cyclic reversed loading test under frequent earthquake. Besides, the fire response test, including temperature rising and lowing, is made by fixing the axial compression ratio of the column. For KJ2 ,the fire response test at the fixed axial compression ratio is made. The deformation response of the concrete frames in fire was studied. Comparative analysis of the apparent phenomenon, temperature curves, bearing capacity change of the frame are made based on the test results of KJ1 and KJ2 .According to the simplified temperature distribution, the ultimate bearing capacity of the column under the high temperature are preliminarily determined.The test results of KJ1 contain the determination of cracking load, development of cracks, width of cracks, get the P-ΔHysteretic Curves and skeleton curves,which can provide the initial damage state for the following fire test. It is testified that the frame is in elastic state and the deformation growing when the load is increasing before the cracking. After the cracking, the frame is in plastic state, and the Hysteretic Curves present nonlinearly. With the loads gradually increasing, the stiffness decreasing, Hysteretic Curves areas increasing and the structure become nonlinearly.The fire response tests of the two frames are made . The change of the temperature and axial displacement of frame column in certain measuring points are gained. Compared analysis of the axial deformation and the temperature curves in the same section are made. It is concluded that: heat transfer of KJ1 is faster than that of KJ2,and the axial deformation of frame column in KJ1 is larger. The stiffness degradation of KJ1 is more serious. But the axial deformation of the two frames has apparently recovery. In the high-temperature of fire, the capacity of the column decrease obviously, which is showed as the decrease of strength of section, the growing of the deformation and the decrease of the performance of the concrete .Finally , it is showed that the calculation results and finally test phenomenon is consistent according to the simplified section.