The issues of joint deformation of monolithic and precast concrete in precast-monolithic structures are considered. The stages of the stress-strain state of the contact seam of the interface during its loading are determined. A method for calculating the contact seam is proposed, performed on the basis of Deryagin's binomial law of friction, and taking into account both the friction forces and the adhesion forces, as well as the inclusion of transverse reinforcement in the deformation process. Based on the works of Prof. Deryagina B. V. the application of a single "true" coefficient of friction for friction and adhesion forces is proposed. The substantiations based on experimental studies of various scientists, the possibility of applying the binomial law of friction in relation to the issues of joint deformation of monolithic and precast concrete at the 1st stage of the stress-strain state are given.

Keywords: prefabricated monolithic structures, contact seam, bearing capacity, friction, adhesion, strength, binomial law of friction, precast concrete, monolithic concrete