钢绞线锚入式预制砼框架节点构造及试验

Structural measures and experimental study of precast concrete joints of anchored prestressing strands in frames

为了解决常见预制混凝土框架节点生产安装难度大的问题,提出钢绞线锚入式新型预制混凝土框架梁柱节点形式.针对构造措施设置概念进行讨论,为了研究其中2个关键构造措施的有效性,开展4个足尺预制节点的低周反复荷载试验.这2个构造措施分别为增设附加直钢筋和预制梁下部架立筋增设无黏结段.结果表明,附加直钢筋能够有效增强钢绞线锚入式新型预制混凝土框架梁柱节点的抗震性能;预制梁下部架立筋局部无黏结段对节点性能影响较小,建议去除该措施;塑性铰外移的构想未能实现,但强柱弱梁设计原则可以保证该节点破坏模式为梁铰破坏.

A new precast concrete joint of anchored prestressing strands was proposed to make contruction of precast beam-to-column connections easier.Concepts of structural details in the proposed system were discussed.Four full-scale cruciform specimens were tested under pseudo-static loadings to evaluate two structural details.Those are additional bars and a small unbonded length of two bottom deformed bars in a precast beam.Results show that additional bars can effectively improve overall seismic resistance of the proposed system.A small unbonded length of two bottom deformed bars in a precast beam has little influence on structural performance of test specimens,therefore it can be removed.Making plastic hinge away from the interface between beams and columns does not work by adopting the proposed measures.Strong column-weak beam philosophy is effective for the new joint to ensure concentration of main damage at beam ends.