ABSTRACT

In this study, a new type of non-through-core anchorage is proposed to anchor longitudinal reinforcing bars (rebar) in reinforced concrete (RC) coupling beams into concrete-encased, concrete-filled, steel tube (CFST) composite shear walls. The cyclic behaviour and anchorage performance of the coupling beams is investigated. The concrete-encased CFST wall consists of two boundary CFST components and an outer RC component. U-shaped reinforcing bars are embedded in the concrete-encased CFST wall to anchor the longitudinal rebars into the RC coupling beams. Cyclic loading tests are conducted on six wall-beam joint specimens, for a constant axial load on the wall and a cyclic load on the coupling beam. The test parameters include the rebar anchorage construction, the concrete strength, and the span-depth ratio of the RC coupling beam. The test results are used to perform a detailed analysis of the failure modes, hysteretic responses, strains, skeleton curves, bearing capacities, ductilities, and energy dissipation capacity. The specimens exhibit highly stable hysteresis behaviour and large inelastic rotation with a high damage tolerance. Slippage is observed after the appearance of diagonal shear cracks, which lead to clear pinched hysteresis behaviour. Interestingly, the buckled longitudinal rebars develop strain later than the directly anchored longitudinal rebars. The proposed anchorage construction can accommodate the largest residual deformation and has a reliable anchoring capacity.

摘要

在这项研究中，提出了一种新型的非穿芯锚固，将钢筋混凝土（RC）连梁中的纵向钢筋（钢筋）锚固到混凝土包裹的钢管混凝土（CFST）复合剪力墙中。研究了连梁的循环性能和锚固性能。混凝土包裹的 CFST 墙由两个边界 CFST 构件和一个外部 RC 构件组成。U形钢筋嵌入混凝土包裹的CFST墙中，以将纵向钢筋锚固到RC连梁中。对六个墙梁接头试样进行循环载荷试验，墙体上的轴向载荷恒定，连梁上的循环载荷。试验参数包括钢筋锚固施工、混凝土强度、RC连梁跨深比。测试结果用于对失效模式、滞后响应、应变、骨架曲线、承载能力、延展性和能量耗散能力进行详细分析。试样表现出高度稳定的滞后行为和大的非弹性旋转以及高损伤容限。在出现对角剪切裂纹后观察到滑移，这导致明显的收缩滞后行为。有趣的是，弯曲的纵向钢筋比直接锚固的纵向钢筋产生应变要晚。所提出的锚固结构可以容纳最大的残余变形，并具有可靠的锚固能力。试样表现出高度稳定的滞后行为和大的非弹性旋转以及高损伤容限。在出现对角剪切裂纹后观察到滑移，这导致明显的收缩滞后行为。有趣的是，弯曲的纵向钢筋比直接锚固的纵向钢筋产生应变要晚。所提出的锚固结构可以容纳最大的残余变形，并具有可靠的锚固能力。试样表现出高度稳定的滞后行为和大的非弹性旋转以及高损伤容限。在出现对角剪切裂纹后观察到滑移，这导致明显的收缩滞后行为。有趣的是，弯曲的纵向钢筋比直接锚固的纵向钢筋产生应变要晚。所提出的锚固结构可以容纳最大的残余变形，并具有可靠的锚固能力。