钢骨超高强混凝土柱-钢骨普通混凝土梁组合框架抗震性能试验研究

Experimental study on seismic behavior of steel reinforced ultra-high strength concrete column-steel reinforced normal-strength concrete beam composite frame

为研究钢骨超高强混凝土柱-钢骨普通混凝土梁组合框架的抗震性能,按1/4缩尺比例制作了两个两跨三层框架模型试件,其中一个为钢骨普通强度混凝土框架模型对比试件。通过低周反复荷载试验,研究了两个框架模型试件的破坏形态、荷载-位移滞回曲线、水平承载力、位移延性、耗能能力、承载力退化和刚度退化等抗震性能,并进行了对比分析。试验结果表明:在试验轴压比为0.38时,二者均能实现梁铰破坏机制,荷载-位移滞回曲线均较饱满,两框架的整体及各层间位移延性系数均大于3.0,具有良好的延性;在承载能力、位移延性、耗能能力、承载力退化和刚度退化等方面,组合框架优于钢骨普通强度混凝土框架,表明在超高强混凝土中通过合理地配置钢骨和高强箍筋,既能充分发挥其高强抗压性能,提高承载能力,又能改善其脆性,增强构件延性,从而提高框架结构体系的抗震性能。

To investigate the seismic behavior of steel reinforced ultra-high strength concrete （SRUHSC） column-steel reinforced normal-strength concrete （SRNSC） beam composite frame, two one-fourth scale two-span, three-story frame specimens were designed and constructed, and one of them is SRNSC frame. Low reversed cyclic loading tests were conducted on two frame specimens. The failure process and modes were described, meanwhile the hysteretic curves, skeleton curves, bearing capacity, displacement ductility, energy dissipation capacity, stiffness, and strength degradation were compared and analyzed. The research results show that the failure patterns of SRUHSC frame is similar to the SRNSC frame. When the experimental axial loading ratio is 0.38, the beam hinge failure mechanism is achieved for the two frames, and the hysteretic curves are plump. Moreover, the displacement ductility coefficients of two frames are all more than 3.0, which shows that the specimens have excellent seismic behavior with sufficient ductility. However, in terms of bearing capacity, displacement ductility, energy dissipation capacity, strength and stiffness degeneration, etc. , SRUHSC column-SRNSC beam composite frame is totally better than the SRNSC frame, which indicates that encasing structural steel and high-strength stirrups into the ultra-high strength concrete is a way for alleviating the problem of brittleness and improving structural carrying capacity by significantly making use of the compressive high strength property and enhancing the structural ductility. Therefore, the seismic performance of the SRUHSC column-SRNSC beam composite frame structure system is effectively improved.