经历弱震损伤的混凝土框架结构抗火性能试验研究

Experimental Analysis of Fire Resistant Performance of Concrete Frame with Damage Caused by Weak Earthquake

设计了2榀配筋相同的足尺寸单层单跨混凝土框架KJ1、KJ2,对KJ1先进行模拟经历弱震损伤的低周反复荷载试验,接着进行了固定轴压比下的火灾反应试验,包括升温和降温过程;对KJ2直接进行固定轴压比下的火灾反应试验。研究了混凝土框架在火灾中的温度及变形反应,对KJ1、KJ2在试验后的表观现象、温度曲线、承载力变化等方面进行了对比分析,同时根据简化的温度场初步计算了框架柱的高温极限承载力。通过试验和理论分析比较表明,计算结果与最终试验现象从定性上分析是相符的。

Two monolayer concrete frames with the same reinforcement,KJ1 and KJ2,were designed.KJ1 was designed to simulate low cyclic reversed loading test under weak earthquake.Besides,the fire response test,including temperature rising and lowing,was made by fixing the axial compression ratio of the column.For KJ2,the fire response test at the fixed axial compression ratio was 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 frames were 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 was preliminarily determined.It is illustrated that the calculation results and finally test phenomenon are consistent according to the simplified section.