Innovation Connection for Precast Frames Using Debonded Tendons

使用脱粘筋预制框架的创新连接

• 批准号: 9300990
• 负责人: M. J. Nigel Priestley
• 金额: $ 1.48万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-15 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9300990&HistoricalAwards=false
• 关键词: Innovation; Connection; Precast; Frames; Using

Precast concrete frames using beam elements connected to multi-story column elements with post-tensioned prestressing tendons has been identified as an economically viable method of construction for tall buildings. Recent research has indicated that beam-column joint subassemblages using fully grouted tendons developed ductility comparable to monolithic reinforced concrete subassemblages designed to current specifications. But the tendons often suffer excessive stiffness degradation at low displacements after moderate ductility levels had been chieved. This was caused by a reduction of effective prestress clamping force through the column, resulting from inelastic strain of the prestressing tendon at the critical section. This project conducts a pilot study to experimentally verify a new concept for connecting precast seismic frames using unbonded prestressing tendons. The tendons will connect precast beam and column sections which allows a nonlinear elastic response and achieves a considerable displacement capacity. This capacity is free from problems associated with permanent deformation, thus enable the joint shear capacity to be enhanced without the need for extensive joint shear reinforcement. Two large scale test units representing an external and an internal connections respectively will be constructed and tested under cyclic lateral deformations using the existing pseudo-dynamic testing facility at University of California, San Diego. Conservative transverse reinforcement details will be chosen and heavily strain gauged. It is expected that recommendations for reduced reinforcement will be made and verification of the concept will be achieved from the experimental research. This project is supported under the provision of Small Grants for Exploratory Research (SGER) program.

预制混凝土框架，使用连接到 后张预应力多层柱单元 肌腱已被确定为一种经济可行的方法 高层建筑的建造。 最近的研究 表明梁柱节点子组合体充分利用了 灌浆钢筋束的延展性与整体式钢筋束相当 钢筋混凝土组件设计， 规范. 但肌腱经常遭受过度的痛苦 低位移时的刚度退化 延展性水平已经达到。 这是由一个 有效预应力夹紧力的减少， 柱，由预应力的非弹性应变引起 关键部位的肌腱。 该项目进行了一项试点研究， 验证连接预制抗震框架的新概念 使用无粘结预应力筋。 肌腱将 连接预制梁和柱段， 非线性弹性响应，并实现了相当大的 位移能力。 这种能力不受 与永久变形相关的问题，因此 使节点抗剪承载力得到增强， 需要大量的接缝抗剪加固。 两个大规模测试单元，分别代表外部和 将分别建造内部连接， 在循环横向变形下进行测试，使用现有的 拟动力试验设备 加州，圣地亚哥。 保守横断 钢筋的细节将选择和严重应变 测量。 预计，关于减少 将进行加固并验证概念 将从实验研究中实现。 该项目得到了小 探索性研究（SGER）计划的赠款。