Abstract:Totally 54 concrete specimens with different concrete strengths(C30, C40 and C50) were designed, and each category of strength contains 6 different interfacial roughness conditions. Through carrying out the single shear test, the influence of concrete surface roughness on bonding property of CFRP concrete beam was researched. The result indicates that among six different interfaces, the concrete interface with the roughness of 044 carries the optimal bonding property. The ultimate load and the bonding strength of the CFRP concrete interface are respectively elevated by 36%51% and by 124%221%. The roughness parameter exerts significant influence to the effective bond length, and it is elevated by 273% to the largest extent in the existing models. The effective bond lengths of six interfaces are reduced as roughness increases generally. The τ s curves of interfaces with the roughness from 025 to 044 are generally with the same rigidity in the friable area which shall be shorter with the increase of interface roughness. From the perspective of plastic stage, the bonding stress slip curves of six interfaces are overall declined in different slopes. Eventually, the interfaces are de bonded with the slip values from 004mm to 035mm.