In order to investigate the mechanisms of debonding of urban roads, this thesis focuses on their characterization in the laboratory. In this work, the idea is to know whether the presence of water (by infiltration into materials) combined with mechanical bending can play a role in the deterioration of the interfaces coupling especially of the cement concrete to the asphalt concrete. A 4-point bending test allowing to generate interface failure in mixed mode (mode I and II) is chosen a priori and adapted. The mechanical analysis of the test is conducted in plane strain with a Multi-particle elastic Model of Multilayer Materials specifically dedicated to the study of edge effects in multilayer structures under bending, the M4-5n. The problem written analytically and solved in Scilab allows optimizing the geometry of the specimens in order to facilitate the delamination. The testing device is developed in the laboratory. Bilayer specimens Alu/PVC are used to calibrate the testing device. In order to immerse the specimens in water during the tests, a specific aquarium is constructed. The experimental results demonstrate the effect of temperature on the resistance of the interface. The techniques of Digital Image Correlation are used to experimentally measure the crack opening and sliding displacement. These techniques are used to determine the stress intensity factors and the energy release rate given by Dundurs. These values are compared successfully with those of M4-5n. In the 20°C water, the experiments show that water privileges the process of debonding.