| The FRP strengthening used for bending beam and other flexural members is a kind of very common and prospective reinforcement form. The experimental analysis and application monitoring indicate that the ultimate capacity of components can greatly increased by pasting FRP sheets. In order to meet the applicability, durability and safety of members, only pay attention to the bearing capacity is not enough, many cases of the deflection of the structure also needed to be controlled; especially some components' failure is controlled by their deflection.Firstly, several methods of strengthening and the research status quo in FRP strengthening flexural concrete member are introduced in this paper. And then the material performance of FRP and adhesive resins systemically is described. All calculation methods about deflection of reinforced concrete beams strengthening with FRP sheet are be summarized and analysis. We proposed an applicable method based on it.The method combined with the suggestion which proposed by ACI318 for the deflection of the RC beam and the suggestion proposed by ACI440 for the deflection of the beam with FRP bars; an applicable method used for calculate of deflection is derived. Which first use Branson equation to calculation the effective inertial moments of the beam, then calculates the deflection of reinforced beams. Considers the tension of strengthen beam is undertake by reinforcements and FRP sheets. The equation about effective height and depth of compression when the beam was cracked are derived. Because of FRP sheets and reinforcements have differences in performance, and the effect about deflection is also different. We propose a parameter modified them.Lastly, we collect experimental results of 16 groups rectangular beam and 6 groups of T-beam which reinforced by CFRP or GFRP respective, compare it with calculation results, found that they are very nearly, which proves the accuracy of the method, it can be used in practical engineering.
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