大应变FRP-再生混凝土-钢双壁空心柱受力机理及设计方法

Against the background of the sustainable development demand in civil engineering all over the world, an innovative hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns is proposed by combining two recycled green materials together: one is recycled aggregate concrete and the other is the newly developed large-rupture-strain FRP (LRS FRP) which is made from recycled plastic bottles. This project will start with the investigation of the compressive behavior of LRS FRP-confined recycled aggregate concrete, followed by the concentric and eccentric compressive behavior of the proposed hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns , and the interaction mechanism between the LRS FRP and the inner steel tube under concentric and eccentric compressive conditions. The performance of the hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns under combined axial and lateral loading will be evaluated thereafter. On the base of these works, an in-depth study on the structural characteristics (including the ductility, energy dissipation, stiffness degradation, etc) and the development law of plastic hinge of the hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns will be conducted.The implementation of this project will provide a better understanding of the structural performance of the hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns and finally lead to further establishment of the design of hybrid LRS FRP-recycled aggregate concrete-steel double-skin tubular columns.

绿色可持续发展已经成为土木工程发展的一个重要方向，本项目创新性地将两种可再生材料结合起来：一种可再生的大应变FRP（Large-rupture-strain FRP, 简称LRS FRP, 断裂应变大于5%）和再生混凝土。提出一种绿色可持续发展的大应变FRP-再生混凝土-钢双壁空心柱新型结构。以大应变FRP-再生混凝土-钢双壁空心柱为研究对象，逐步开展大应变FRP约束再生混凝土的应力应变关系、大应变FRP-再生混凝土-钢双壁空心柱轴压性能、大应变FRP-再生混凝土-钢双壁空心柱偏压性能、大应变FRP-再生混凝土-钢双壁空心柱在轴压和侧向往复荷载作用下受力性能研究。探索大应变FRP-再生混凝土-钢双壁空心柱中FRP与钢管的相互作用机理，明确该相互作用对内填再生混凝土应力应变关系影响，建立大应变FRP-再生混凝土-钢双壁空心柱的设计方法。

在本项目的资助下，针对组合使用再生混凝土和一种可再生的大应变FRP结构的力学性能，开展了以下研究内容：.（1）提出了基于刚度的大应变FRP约束混凝土模型及其在桥梁抗震加固中的应用；（2）开展了大应变FRP约束再生混凝土柱的轴压试验研究及模型评估；（3）开展了大应变FRP约束再生混凝土双管柱的轴压试验研究及模型评估；（4）开展了大尺寸FRP管约束多管柱轴压试验及复杂约束条件下混凝土增强机理研究；（5）开展了高轴压比下的大应变FRP加固非延性钢筋混凝土柱的抗震试验研究及数值模拟；（6）开展了大应变FRP-混凝土-钢空心双管柱抗震性能试验研究。