Unified Evaluation of Failure Mechanism of Beam-Column Joint in Reinforced Concrete and Pre-stressed Concrete Frames

钢筋混凝土与预应力混凝土框架梁柱节点破坏机理的统一评价

基本信息

批准号：
16360280
负责人：
NISHIKAWA Takao
金额：
$ 7.87万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

Shear resisting mechanism and failure mechanism of plane and three-dimensional beam-column joint panels were studied through a series of static tests under reversed cyclic loading; twelve specimens with plane cruciform shape and two three-dimensional specimens made of pre-stressed reinforced concrete (called as PRC) and precast pre-stressed concrete (called as PCaPC).Conclusions drawn by the study are mentioned as follows.1) Joint panel covered by four transverse beams in PCaPC frames failed in shear similarly to R/C beam-column joints.2) The beam-column joint with unbonded tendons within a joint panel also failed in shear.3) Shear strength of cruciform PCaPC beam-column joint panel can be computed by the same manner as R/C beam-column joints, i.e., as a function of concrete compressive strength regardless of the bond condition along beam post-tensioning tendons and the arrangement of the tendons.4) Joint shear strength was enhanced to 25 percent or 13 percent by four or three transver … More se beams framing into the joint panel respectively comparing with that of a plane beam-column joint specimen.5) The capacity point of a set of maximum story shear forces in each direction under bi-lateral loading was located at the outside of rectangular bi-directional interaction surface of joint shear capacity. This means that safety to earthquake excitations can be sustained for a PCaPC beam-column joint by designing joints to shear forces in respective directions independently.6) For PRC plane beam-column joint specimens, three failure types were observed. A story drift angle at the peak shear capacity varied from 1.5 % to 2.9 %. For four specimens which were reinforced by deformed PC tendons and failed by beam flexural yielding, PC tendons ruptured after a story drift angle of 2 % and lateral story shear capacity descended remarkably.7) Residual flexural crack width at beam critical sections increased suddenly due to no tensile yielding but bond deterioration of beam longitudinal reinforcement or PC tendons. Less

通过在反向循环载荷下进行一系列静态测试，研究了平面和三维梁柱接头面板的剪切机理和破坏机制。十二个标本具有平面十字形形状和两个由预压力钢筋混凝土制成的三维标本（称为PRC）和预制预压力混凝土（称为PCAPC）。连接面板内的不粘结肌腱也在剪切中也失败了。3）十字形PCAPC PCAPC梁圆形关节面板的剪切强度可以按与R/C梁圆柱接头相同的方式计算，即，即通过触发后弯曲的束缚和三个侧面的递归量的粘结条件的混凝土压缩强度的函数。与平面梁柱接头样品相比，分别构架到关节面板中。5）5）在双边载荷下，在每个方向上，一组最大故事剪切力的容量点位于关节剪切能力的矩形双向相互作用表面的外部。这意味着，通过设计关节以独立在每个方向上的剪切力来实现PCAPC梁柱接头的安全性激发。峰值剪切能力的故事漂移角度从1.5％到2.9％不等。对于四个通过变形的PC肌腱加强并因横梁弯曲屈服而无法加强的样品，PC肌腱在2％的故事漂移角度的漂移角度破裂，而横向故事剪切能力显着下降。7）梁临界切片处的残留弯曲裂纹宽度突然增加，由于没有拉伸的屈服，但较长的束缚屈服，但持续了远距离预备或PC的粘合定义。较少的