The methodology and the main positions of physically based models of adhesion between concrete and reinforcement based on average tangential stress were considered in the article. The research proved and physically substantiated the linear connection between direct and tangential stresses during the pulling out of a reinforcement bar from a concrete prism. Based on experimental data, the linear law of change of these parameters was statistically verified. When a reinforcement bar is pulled out of a concrete prism, its stress-strain state is significantly affected by shrinkage. That is why the average tangential stresses of adhesion of concrete have a non-zero value when the direct stresses at the end of the reinforcement steel are equal to zero. These inherent tangential stresses occur as a result of concrete contraction. It was proved that the tangential stresses from concrete contraction have the same sign as the tangential stresses during pulling out of a reinforcement bar from a concrete prism. It is shown that the presence of inherent tangential stresses confirms the correct use of the method of average tangential stresses over the entire operating range of a reinforced concrete element. Two methods of obtaining the main parameters of the adhesion between concrete and reinforcement were proposed in the research work. The first method makes it possible to determine the main parameters of adhesion based on the construction of normal stress distribution diagrams along the length of the sample. The second is based on the graphs of displacements of the free-ended and loaded-ended reinforcement. The reliability of both methodologies was confirmed by the statistical processing of experimental data of various researchers.