配置CRB600H箍筋的混凝土框架梁抗震抗剪试验研究

EXPERIMENTAL RESEARCH ON SEISMIC BEHAVIOR AND SHEAR BEHAVIOR OF CONCRETE FRAME BEAM WITH CRB600H STIRRUPS

采用悬臂式低周往复加载方式,对8个配置CRB600H高强箍筋混凝土框架梁进行了抗震抗剪性能试验,对高强箍筋梁的破坏形态、滞回性能、抗剪承载力、变形能力以及高强箍筋的应力发挥水平进行了研究,分析了含箍特征值和箍筋形式对其抗震抗剪性能的影响。试验结果表明:各梁端均发生了纵筋屈服后的剪切破坏形态;试件的极限位移角在1/80~1/37之间。在达到峰值承载力时,梁端CRB600H箍筋能够达到实际屈服强度;含箍特征值较高的试件,其承载力和变形能力较高,耗能能力较低;箍筋形式对抗剪承载力和变形能力影响不大,箍筋肢数多的试件耗能能力较高。将收集到的国内外高强箍筋混凝土梁的抗震抗剪承载力试验结果与我国GB 50010-2010《混凝土结构设计规范》的公式计算结果进行了对比,结果表明:按规范计算得到的抗震抗剪承载力略偏高,规范公式不适宜用于高强箍筋梁的抗震抗剪承载力计算。

Seismic shear tests using cantilevered quasi-static reciprocating loading were conducted for 8concrete frame beams with CRB600H high-strength stirrups.The failure modes,hysteretic behavior,shear bearing capacity, deformation capacity and stress magnitude of CRB600H stirrups were studied.The influences of the stirrup characteristic values and stirrup arrangements on the seismic shear behaviors were also investigated.The test results indicated that the shear failure after the longitudinal reinforcement yielding occurred at each beam end,and the ultimate displacement angle of the specimens was between 1/80 and 1/37.At the peak load,CRB600H stirrups reached their yield strength.Moreover,increasing the stirrup characteristic value could improve the seismic shear capacity and deformation capacity of specimens and decrease their energy dissipation capacity.The stirrup arrangements had little effect on the seismic shear capacity and deformation capacity and the specimens with more stirrup legs had greater energy dissipation capacity.The test resuhs of the seismic shear capacity of concrete beams with high-strength stirrups were compared with the calculated results basted on GB 50010-2010,and it was founded that the formula of GB 50010-2010would overestimate the seismic shear capacity of the beams.The formula is not suitable for the seismic shear design of concrete beams with high-strength stirrups.