高强箍筋高强混凝土短柱抗震性能试验研究

Experimental research on seismic behavior of high-strength concrete short columns with high-strength stirrups

为了研究高强箍筋约束高强混凝土短柱在地震作用下的抗震性能,采用建研式加载装置,通过14根高强混凝土短柱试件的低周反复加载试验,研究了高强箍筋约束高强混凝土短柱的破坏形态、滞回性能、骨架曲线、变形和延性、耗能能力以及高强箍筋的应力发挥水平和受剪承载力计算等,分析了轴压比、剪跨比、箍筋强度、箍筋间距、箍筋形式和混凝土强度等因素对短柱破坏形态、滞回性能和承载力的影响。结果表明:短柱破坏形态受设计参数的影响有剪切破坏和剪切黏结破坏两类;与普通强度箍筋混凝土短柱相比,高强箍筋高强混凝土短柱在节约材料的同时具有优越的抗震性能和抗倒塌能力;达到极限荷载后,箍筋的应变发展较快,高强箍筋的强度发挥充分,短柱的抗震性能明显改善;通过对高强箍筋应力取值进行适当修正,采用GB 50010—2010规范公式计算高强箍筋高强混凝土短柱的受剪承载力是可行的。

Low cycle reversed loading tests of 14 reinforced concrete short columns were conducted to research the seismic behavior of high-strength short columns confined with high-strength stirrups. The failure patterns, hysteretic behavior, skeleton curve, deformation capacity, dissipated energy parameters, stress magnitude of high-strength stirrups and shear bearing capacity were studied. The influences of axial compression ratio, span-depth ratio, stirrup yield strength, stirrup spacing, stirrup configuration and concrete compression strength on the bearing capacity and ductility of experimental specimens were studied. The test results indicate that the failure patterns of specimens are shear failure or shear-bonding failure as the influence of design parameters. Compared with high-strength concrete short columns with ordinary strength stirrups, high-strength concrete short columns with high-strength stirrups not only have advantages of material saving, but also have good seismic performance and collapse resistant capacity. Stress and strength of the stirrups are developed fully after peak value, and thus seismic behavior of the specimens is improved. The shear capacity of high-strength concrete short columns with high-strength stirrups can be calculated using modified stirrup stress and normal formula proposed by the current codes.