Model of the kinetics of aging of paint and varnish coatings of cement concrete

Information on the kinetics of aging of coatings is presented.The process of moistening was considered as one of the particular cases of aging. During incubation period there is a slight increase, and possibly a decrease in defectiveness. The duration of the incubation period is 0.2 -0.5 of the entire durability.The active stage of damage accumulation begins after the incubation period. In the active stage of accumulation of damages, significant changes occur in the structure and properties of the coating (change in color, shine , cracking, etc.).Determined that the beginning of the active stage of accumulation of lesions coincides in time with the first significant changes in the surface area of the coating. It was found that there is a correlation between the experimental data on the kinetics of damage accumulation, the degree of chalking, and surface area. It lies in the fact that the active stage of damage accumulation coincides with the beginning of chalking of coatings. An analytical dependence is proposed that makes it possible to estimate the area of the defective surface of the coating during aging. The dependence of the level of damage accumulation on the duration of tests can be described by a logistic curve (or Pearl curve)