Abstract: In this paper, the flexural performance of the concrete beams strengthened with U-shaped high strength steel wire and permeable polymer mortar (HSSW-PPM) were studied. An experimental study including six reinforced concrete (RC) beams and five prestressed reinforced concrete (PRC) beams strengthened with HSSW-PPM was carried out under static loading. The influences of damage intensity, level of effective prestressing and loading regime on the flexural performance of these strengthened beams were investigated. Some conclusions were extracted from the testing as follows: (1) The cracking development can be effectively restrained using the proposed U-shaped strengthening method with HSSW-PPM, and the flexural load-carrying capacity, the rigidity, and the ductility of the strengthened RC/PRC beams can also be enhanced. (2) The rating of rigidity of the strengthened beams might be occurred under a recycle loading, and the flexural carrying capacity of the strengthened RC/PRC beams can not be obviously changed while the initial damage degree changed. This kind of study may be employed as the reference of flexural strengthening for the amount of existing RC/PRC beam structures.