Building and Architecture Paints and Coatings

Abstract

Information is given on the strength of the coatings of cement concrete for the exterior walls of buildings. It was found that the strength of the coating depends on the quality of its appearance. A strength model is proposed depending on the surface roughness of the coating. The influence of the scale factor on the change in the strength of coatings is established. To assess the long-term strength of the coatings, we studied the temperature-time dependence of strength. The values of the activation energy of the destruction process of some coatings are experimentally determined. The dependence of the long-term strength of the coatings on tensions is given. The kinetics of changes in the short-term strength of coatings during aging is considered from the perspective of the kinetic concept of the strength of solids. The condition for coating cracking is obtained. Taking into account the influence of the scale factor and the conditions of brittle fracture of coatings, a method for choosing the optimal coating thickness is proposed. paint after 35 cycles is estimated as AD1 and AZ1, which corresponds to the state of coating with no discoloration, chalking, and dirt retention. Silicate-based coatings are more susceptible to degradation. The condition of coating based on silicate paint is estimated as AD3 and AZ3. The test results showed that the “ failure ” of coating based on silicate paint occurred after 40 freeze-thaw cycles, while the state of the coating based on polysilicate solution was evaluated as AD2 and AZ2. The “ failure ” of the coating based on the polysilicate solution occurred after 50 test cycles.