预应力中空棒构件设计与力学特性

为满足装配式建筑节点接缝混凝土抗震性能的需要,以一种自平衡预应力中空棒为研究对象,研究接缝位置短杆件施加预应力的效果。根据力的平衡机理,对结构内部钢棒施加压力使结构外部钢管协调受力拉伸,达到设计预应力后由螺母锁定,将杆件埋入到装配式节点接缝混凝土,浇筑早强灌浆料,待固结达到预定强度释放反力棒,依靠外螺纹结构与混凝土的粘结力自锚实现接缝混凝土施加预应力。力学性能分析方面,研究杆件张拉阶段、静置松弛阶段应力变化及损失情况,验证了杆件张拉完成至放张前应力存储的有效性,通过分析杆件放张后应力分布、预应力损失等参数,验证了杆件应用到节点混凝土后传递应力的机理及有效性,并采用有限元方法分析预应力混凝土构件应力分布规律。研究结果表明预应力中空棒技术作用于装配式节点接缝混凝土具有较高的抗震和耗能能力,对装配式建筑节点混凝土高抗震性能的实现提供了一种新的技术手段。

Design and mechanical properties of prestressed hollow bar

To meet the needs of the seismic performance of concrete at the node joints of assembled buildings, a self-balancing prestressing hollow bar was used to realize the effect of pre-stressing the short rod at the joint position. According to the force balancing mechanism, pressure was applied to the steel rod inside the structure, which led to the coordinated tension in the steel tube outside the structure to achieve the design. After pre-stressing and locking by the nut, bury the rod into the concrete of the joints of the assembled nodes, pour the early-strength grout, and wait for the consolidation to reach the predetermined level. Strength-releasing reaction rods, relying on the self-anchoring of the bond between the external threaded structure and the concrete to achieve the pre-stress applied to the joint concrete. The stress changes and losses in the tensile and static relaxation phases of the rod were investigated, and the tensile and static relaxation phases of the rod were verified. The validity of stress storage from completion until release was verified by analyzing parameters such as stress distribution and prestressing losses after the rod was released. The mechanism and effectiveness of stress transmission after application for odal concrete and the analysis of stresses in prestressed concrete members using finite element method distribution pattern. The pre-stressing hollow bar technology acting on the assembly nodal joints concreted has high seismic and energy-consuming capacity for assembly building the realization of high seismic performance of nodal concrete provides a new technical approach.