表层嵌贴预应力CFRP板条加固钢筋混凝土梁的应力传递行为

表层嵌贴预应力FRP板条加固钢筋混凝土结构技术可充分发挥FRP材料强度，且不需设置永久锚具，具有较大的潜力。以试验得到的嵌贴FRP混凝土粘结滑移关系为基础，建立了嵌贴预应力CFRP板条与混凝土的粘结应力微分方程，并根据边界条件推导了方程的解析解，得到了嵌贴预应力CFRP板条放张后界面粘结应力、CFRP拉伸应力的分析模型。与试验结果的比较表明，该模型得出的界面粘结应力及CFRP拉伸应力与试验结果吻合较好。在此基础上，考虑放张后CFRP混凝土界面不出现剥离的条件，分析了粘结界面能抵抗的最大容许预应力。

Stress transfer of reinforced concrete beam strengthened with near-surface mounted prestressed CFRP strips

Due to the advantages of making full use of high strength of FRP and saving the cost of premature anchorages for prestressed FRP, the technique of strengthening with prestressed near-surface mounted (NSM) FRP was considered as a potential technique for strengthening of reinforced concrete structures. The bond behavior of the NSM CFRP strip in the stress transfer length after releasing the prestress was studied. Based on the bond slip constitutive relationship obtained from experimental research, the differential equation of the bond stress at the NSM FRP-concrete interface was established. Then the analytical solution of the differential equation was acquired according to the boundary conditions, and the equations of distribution of the bond stress at the bonded interface and the tensile stress of CFRP were presented. The theoretical results were in good agreement with the test results, which indicated that the equations could be used to predict the distribution of bond stress at the NSM FRP-concrete interface after prestressing force release. Moreover, the maximum allowable pre-stress was obtained by considering no debonding at the bonded joint to be induced due to pre-tension release.