高轴压比高强混凝土足尺框架柱的破坏形态分析

THE FAILURE MODAL ANALYSIS OF FULL-SCALE HIGH STRENGTH CONCRETE FRAME COLUMNS WITH HIGH AXIAL COMPRESSION RATIOS

为了研究足尺高强混凝土框架柱的抗震性能,通过对9根高轴压比高强纵筋高强箍筋高强混凝土井字箍矩形截面足尺框架柱在低周反复荷载作用下的试验研究,讨论和分析了框架柱的裂缝开展过程及分布、破坏机理和破坏形态。研究表明:高强混凝土足尺框架柱裂缝长度较长,且裂缝开展较为突然;轴压比较小时,裂缝分布较密集;轴压比较大时,裂缝分布较疏散;足尺框架柱破坏时,混凝土脱落较为严重;轴压比、混凝土强度等级及箍筋间距是影响框架柱破坏形态的主要因素;箍筋形式、配箍率(或配箍特征值)对框架柱的破坏形态影响较小;截面尺寸越大、截面长宽比越大,试件破坏得越严重。

In order to research the aseismic behaviors of full-scale high-strength concrete（HSC） flame columns, the crack distributing and developing rules, failure mechanisms and modes were discussed and analyzed by the basis of experimental study of 9 full-scale HSC rectangular frame columns with high axial compression ratios, high-strength longitudinal reinforcements and transverse reinforcements and rectangular interlocking ties. The main results indicate as follows. The cracking lengths of full-scale HSC columns are longer; the cracks occur abruptly; the cracks distribute densely as the axial compression ratios are lower, and they distribute sparsely as the axial compression ratios are higher; the concrete spalling degrees are severely; the axial compression ratios, the strength grades of concrete and the spaces of transverse reinforcements are the main influencing factors on the failure modes of frame columns; the influencing factors of the modes and ratios of transverse reinforcements （or transverse reinforcement characteristic values） on the failure modes of frame columns are smaller; the larger sectional dimensions and length breadth ratios are, the more seriously the specimens destroy.