中文摘要：

结合二次预应力组合梁的基本原理及特点，分析二次预应力组合梁现有施工技术存在的问题，即模板安装支护、混凝土浇筑、预应力筋张拉锚固困难而复杂，施工工序增加；针对这些问题，研究开发了两种连接器专利产品，一种是双套筒预应力钢筋套管连接器，可以方便地实现一期混凝土中预应力筋套管和二期混凝土中预应力筋套管的连接；另一种是双层套筒钢筋连接器，可以方便地实现一期混凝土中纵向钢筋和二期混凝土中纵向钢筋的连接，从而有效解决二次预应力组合梁现有施工技术存在的问题，提高二次预应力组合梁的技术水平。

英文摘要：

It was introduced basic principle and characteristics of twice prestressed composite beam, and analyzed the problems of the existing construction technology of twice prestressed composite beam, namely, too many processes are involved in constructing the twice prestressed composite beam, and some of the processes such as fabricating and installing the fol＇mworks, pouring concrete, tensioning and anchoring prestressed tendons are rather difficult. In order to solve these construction problems, two patent products were developed and proposed, one is double sleeve prestressed tendon casing connector which can easily realize the connection of prestressed tendon casing in first term concrete and that in second term conetete, the other is double sleeve reinforced connector which can easily realize the connection of reinforcement in first term concrete and J.hat in second term concrete. These two patent products can effectively solve the two existing problems of construction technology, improve the technical level of twice prestressed composite beams.