This article focuses on the degradation process of the concrete surface layer as a two-phase composite. The cause of wear is considered to be a change in the deformation characteristics of the cement-sand matrix due to microcracking, corrosion, etc. A simple mesoscale model of surface wear as a process of aggregate grains falling out of the matrix is proposed. Simulation experiments were conducted to study the process of formation of destruction centers leading to grain rotation inside the matrix. The ANSYS software package was used for numerical calculations. The proposed numerical model can be useful for predicting the behavior of heterogeneous materials during wear depending on the degree of change in the mechanical properties of their structural elements throughout the life cycle. Finally, an engineer can propose methods of protecting the concrete surface and ways of its repair by using this model.