Testing method for interface mode II fracture of plain concrete and fiber-reinforced cementitious composite

The performance of a bi-material interface is one of the major concerns in the repair or strengthening of concrete structural elements. In this study, a novel testing method for interface shear fractures of plain concrete and fiber-reinforced cementitious composites is proposed to avoid tensile failure during the test. Double-edge notched and unnotched specimens are utilized. Analytical, numerical, and experimental investigations are carried out to validate this method. The stress intensity factor K of the double-edge specimen with bi-materials is analytically obtained by the J-integral method. Based on ultra-high toughness cementitious composite (UHTCC)/concrete models, a numerical investigation of the proposed method is performed to confirm its suitability for shear fracture tests. Furthermore, the double-edge UHTCC/concrete specimens are experimentally investigated. The proposed method can be applied to obtain the interface shear parameters of concrete materials, which are needed for analytical or numerical analyses of bi-material interfaces in concrete structures.