空间曲面纤维网格制作及加固水下混凝土柱试验研究

Performance of underwater concrete column reinforced with curved surface space FRP grid under axial compression

平面纤维(FRP)网格以其卓越的性能在特定结构加固方面具有较好的应用优势,但其对小尺寸曲面、异形混凝土结构构件的约束加固并不适用。提出了空间曲面纤维网格制作工艺,制作了曲面纤维网格制品,测试了纤维网格拉伸的力学性能;提出了空间曲面纤维网格加固水下混凝土柱的施工工艺,并进行了轴压试验研究,试验结果表明:空间曲面纤维网格加固水下混凝土试件的轴压性能明显优于未加固混凝土圆柱试件,随着纤维网格纤维用量的增加,加固试件的承载能力和变形能力能有效提高,并取得和陆上试件相近的加固效果,根据纤维网格约束量的不同,水下加固试件的应力-应变曲线表现为软化、强化与临界行为,采用现有FRP约束混凝土模型能够较好地预测空间曲面纤维网格加固水下混凝土的极限应力与极限应变。

Plane FRP grid has the application advantages in strengthening special structures due to its excellent performance, but it may not be applicable to strengthening the concrete structures with small-size surface or special shape. In this study, the manufacturing technologies of curved surface space FRP grid were put forward, then the curved surface space FRP grid products were manufactured and the tensile mechanical properties of the FRP grid were tested. Moreover, the construction technology of underwater concrete columns reinforced with the curved surface space FRP grid was proposed and the axial compressive performance of the columns was investigated. The test results show that the compressive performance of the underwater concrete columns reinforced with curved surface space FRP grid is much better than that of the unreinforced specimens. With the increase in the amount of the fiber in FRP grid, the load carrying capacity and deformation capacity of the reinforced specimens can be increased effectively and can approach those of the reinforced specimens on the land. According to the amount of fiber in FRP grid, the stress-strain curve of underwater reinforced column may exhibit a softening, hardening or critical behavior, and the existing FRP-confined concrete models can predict very well the ultimate stress and ultimate strain of underwater concrete columns reinforced with curved surface space FRP grid.