冷弯薄壁型钢混凝土剪力墙受剪性能试验研究

通过7个冷弯薄壁型钢混凝土(CTSRC)剪力墙的拟静力水平往复试验，研究了其破坏过程和破坏模式，分析了混凝土强度、剪跨比、轴压比、水平分布筋和竖向型钢量等参数对其受剪性能的影响。试验结果表明：随着水平配筋率、轴压比和混凝土强度的增加受剪承载力提高；随着剪跨比提高，墙体受剪承载力降低；轴压比增加可提高墙体刚度，推迟墙体裂缝的出现，但不利于墙体延性；增加水平配筋可使墙体峰值后的承载力保持稳定。研究表明：CTSRC剪力墙与传统钢筋混凝土剪力墙的破坏特征和受力性能不同，在水平力作用下将出现沿冷弯薄壁型钢的竖向裂缝，经历整体墙到分缝墙的演变，避免了脆性剪切破坏。通过合理设计，CTSRC剪力墙可实现正常使用阶段有较高的刚度、峰值后有较好的延性、破坏时仍具有较高的竖向承载能力的目标。

Experimental study on shear behavior of cold-formed thin-walled steel reinforced concrete shear walls

Seven cold-formed thin-walled steel reinforced concrete(CTSRC) shear walls were tested quasi-statically under low cyclic lateral loads to acquire their shear failure process and modes. The effects of the concrete strength, the shear-span ratio, the axial load, and the amount of the horizontal reinforcements were investigated. The test results show that the shear capacity of the wall rises with the increase of the amount of horizontal reinforcements, the axial load and the concrete strength, and reduces with the increase of shear span ratio. The increment of the axial compression ratio postpones cracking but reduces the ductility. The stable post-peak load capacity can be acquired by increase the amount of horizontal reinforcements. In the tests, the CTSRC walls perform the different failure characteristic and behaviors to the conventional reinforced concrete wall, in terms of that they develop from integral walls into slit walls for appearing the vertical cracks along cold-formed thin-walled steel profiles. As the results, the brittle shear failure is extinct. Hence, the properly designed CTSRC shear wall has a higher stiffness in normal service stage, a higher strength and a higher ductility after the peak load, and a higher vertical loading capacity at limit state.