Design of bond strength testing method of concrete layers for creating a material model

The need to determine the bond strength of concrete layers in structural modeling is quite frequent and often encounters a lack of relevant experimental data due to the large number of variables which affect the bond strength. This article describes an experimental method that makes it possible to obtain the experimental data necessary for subsequent modeling of multi-layered concrete composite structures. The experiment is designed to be applicable both to laboratory specimens with defined properties and to samples taken from existing structures. The advantage of this method is its simplicity, minimal equipment requirements, and repeatability. The three-layer specimens, representing a sandwich wall, allow the study of the influence of the age and quality of the concrete on the bond strength, and through image analysis, provide valuable information on deformation, interlayer slip, and crack formation. The results of the experiment may contribute to the determination of a bond strength diagram for multi-layered walls, which can be integrated into software tools for comprehensive structural analyses.