焊接箍筋高轴压比高强混凝土柱裂缝发展

Concrete column crack propagation with welding ring-stirrup high axial compression ratio and high-strength

为研究轴压比、配箍率、箍筋连接形式的变化对混凝土柱裂缝发展的影响,以5根高轴压比、高强混凝土柱试件为研究对象,施加低周反复水平载荷进行拟静力试验,对各试件的破坏形态、混凝土裂缝发展进行研究.结果表明:高强混凝土柱在反复水平载荷作用下先出现水平细小裂缝,随着水平位移加大出现斜向裂缝,并逐渐加长、贯通、加粗,最终柱脚混凝土压碎,发生弯曲破坏;柱达到极限破坏时,大部分纵筋屈服或溢出,部分箍筋屈服;配箍率大、采用焊接环式箍筋的试件承载力较大、耗能大,延性好.

In order to study the effect of the axial load ratio, stirrup ratio, and stirrup joint change on concrete column crack propagation, this paper chose five high axial compression and high-strength concrete columns for testing, and carried out the pseudo-static experiments under low cyclic horizontal loading. The failure modes of samples, concrete column crack propagation were researched. The test result shows that high-strength concrete columns appears hairline cracks with low cycle horizontal loading and slant cracks appear, longer, penetrating, thick with increasing horizontal displacement. Ultimately the column foot concrete crushes, and occurs bending failure. When the load rises to limit rupture on the columns, the most of the longitudinal bars yield or overflow, and part of the stirrups yield. The test result shows that stirrup ratio increase, welding ring-stirrup has higher load-bearing capacity, larger energy consumption and better ductility.