CFRP布加固钢筋混凝土双向板抗弯性能分析

Analysis of Flexural Performance in RC Two-way Slabs Strengthened with CFRP Sheets

选取实际工程中CFRP布加固双向板的实例,利用ANSYS有限元软件建立加固模型,通过逐级递增施加楼面活荷载,对比分析了对比板与加固板的跨中挠度、钢筋应力及承载力,研究了在CFRP布加固方式不同、加固厚度不同及加固量不同时加固板力学性能的规律.结果表明:与对比板相比,CFRP布加固的双向板能有效提高抗弯承载力,减小挠度;贴布面积相同时,分散"#"字型铺贴加固板效果优于密集"#"字型和"+"字型的;适当增加CFRP布粘贴厚度,在原有加固方式基础上增加加固量,均有利于提高板的抗弯承载力;CFRP布宽度增加,有利于提高板的抗弯承载力,但不利于CFRP布强度的发挥.

An instance of a two-way slab strengthened with CFRP sheets from practical projects is selected in this paper. With choosing this strengthened slab, a 3D FEM finite element model is established by ANSYS software. Though applying the floor uniform live load on slab’s surface step by step, the results （including slab’s mid-span deflection, steel stressand bearing capacity） in every step are compared and analyzed between the strengthened and un-strengthened slabs. In addition, the mechanical property laws of strengthened slabs under different CFRP strengthening modes, CFRP thicknesses and CFRP amounts are also explored. Finally, through the above research and analysis, we can draw the results as follows： compared with the un-strengthened slab, strengthened slab can effectively improve slab’s flexural bearing capacity and reduce deflec-tion; the strengthening effect of scattered “#” shape is better than intensive “#” shape and “＋”shape when the area of CFRP sheets is equal; when increasing the thickness of CFRP sheets appropriately, slab’s flexural bearing capacity can be effec-tively improved; increasing CFRP amount is helpful to improve slab’s flexural bearing capacity based on original strength-ening modes; increasing CFRP sheets width can improve slab’s flexural bearing capacity, but go against giving the full play to CFRP sheets tensile strength.