碳纤维布加固钢筋混凝土梁的预应力控制过程

采用弹性理论方法，建立了预应力碳纤维布加固钢筋混凝土梁在放张和承载后界面剪应力的理论计算模型。研究了界面间剪应力在预应力荷载和外荷载作用下的变化规律以及放张后碳纤维中的有效拉应力分布状况。本文的理论计算结果与试验结果吻合。最后得出结论：对预应力碳纤维布加固的钢筋混凝土梁进行初始张拉力控制时，应将放张后梁上缘产生的反拱应力、界面剪应力和承载后界面间剪应力增量三个因素放在一起综合考虑，才能使加固效率达到最高。

Pre-tension control of reinforced concrete beam strengthened with CFRP sheets

A calculation model for the interfacial shear stress of the reinforced concrete beam strengthened with prestressed CFRP sheets was built based on the elasticity theory after releasing and loading. The changes of the interfacial shear stress under the preload and the external load and the distribution of the effective tension stress in the CFRP sheers were calculated. The calculation results coincided with the results of test and the results of the finite element analysis. It was concluded that the optimization of the strengthening by the pri-tension control of the reinforced concrete beam strengthened with the CFRP sheets can only be realized under the condition of overall consideration on three major factors, i. e. the buckling stress on the top of the concrete beam after releasing, the interfacial shear stress and its increment after external loading.