Influence of moisture on the durability of protective and decorative coatings of external walls of buildings

Valentina Loganina,A Glezer,S Roshchupkin

doi:10.1051/matecconf/202032904004

Valentina Loganina, A Glezer + Show 1 more

Open Access

https://doi.org/10.1051/matecconf/202032904004

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Abstract

The article presents the results of a study of the effect of air pressure in the pores of a cement substrate, which occurs when the wall material is moistened, on the crack resistance of protective and decorative coatings. It is shown that the value of air pressure in the pores of the material, provided that the moisture content of the wall material does not exceed the sorption limit, does not pose a threat to the integrity of most coatings. When the moisture content of concrete is higher than the sorption air pressure, it is comparable to the long-term cohesive strength of some protective and decorative coatings (lime, polymer-lime, KhSPE, etc.). When finishing external wall panels with a paint composition based on organic solvents (toluene, xylene, etc.), a saturated vapor-gas mixture is formed in the pores, which helps to reduce the rate of surface condensation. The destruction (peeling, cracking) of coatings from the action of air pressure in the pores of the substrate begins later in comparison with coatings based on aqueous paint formulations.

Highlights

One of the factors affecting the external environment on protective decorative coatings of external walls of buildings is moisture
The peculiarities of the work of protective and decorative coatings of the external enclosing structures of buildings are that in the cold season, through the enclosing structure, water vapor diffuses from the inner surface to the outer [4]
Calculations show that with a concrete moisture content of 8%, the air pressure in the pores in June reaches up to 0.214 MPa, with a moisture content of 12% - 0.244 MPa, which is comparable to the long-term cohesive strength of some protective and decorative coatings

Summary

Introduction

One of the factors affecting the external environment on protective decorative coatings of external walls of buildings is moisture. The air in such pores is compressed and puts pressure on the paint layer, contributing to its destruction [5,6,7]. Inspection results on painted building facades indicate that cracking and flaking are the most common coating defects [8-10]. These defects appear mainly in the spring. In this regard, it is relevant to study the effect of moisture on the cracking and flaking of coatings

Materials and research methods

Research results

Findings

Conclusion