Abstract: In order to reveal the influence of concrete roughness on the interfacial bonding properties between CFRP and concrete，the roughness of concrete was quantitatively assessed through the sand-pouring method，the single shear test of CFRP-concrete interfaces were completed under 6 different conditions of interfacial roughness， and the influences of concrete roughness on the ultimate bond force，bonding strength and bonding slipping curve of the CFRP-concrete interface were investigated，finding that，as compared with the specimen with a roughness of 0. 25，the specimen with a roughness of 0. 44 possesses the best interfacial bonding property，and its ultimate bond force and strength improve by 36% ～ 51% and 124% ～ 221% ，respectively． Then，a model to calculate the effective bonding length of interface was established on the basis of the roughness parameters． From this model，it is found that ( 1) the effective bonding length of six surfaces generally decreases with the increase of roughness; ( 2) the bonding slipping curves of the samples remain consistent in rigidity in the brittle area，and the rougher the interface，the shorter the brittle section; and ( 3) in the plastic stage，the bonding slipping curves of the samples with 6 interface types slide with different slopes，eventually resulting in a stripping damage at a slipping value of 0. 04 ～ 0. 37mm

Key words: bridge engineering, roughness, fiber-reinforced polymer, interface, bond stress, concrete