Research on the resistance of protective coatings for concrete to the effects of atmospheric moisture

The development of the construction industry has led to increased requirements for the operational properties of building materials in general and concrete in particular. Although concrete is designed primarily to withstand structural loads, it must also resist environmental influences to increase its durability. This article presents the results of the influence of the components of protective coatings on the hydro-physical properties of concrete. The edge wetting angle in concrete with a protective coating ranges from 95 to 101 degrees, which is about twice that of uncoated concrete. The mass of concrete under the influence of hygroscopic moisture increases, and after 30 days of exposure, it is 1.1–1.6 wt. % compared to 5.7–5.8 wt. % for control samples. The minimum increase (1.1–1.2 wt. %) is achieved when using coatings with the largest amount of heat-resistant varnish KO-08. The water absorption of the developed coating compositions decreases after 30 days of being in water from 5.2 to 1.6–2.2 wt. % for C20/25 concrete. Low temperatures negatively affect the hydrophysical properties of protective coatings, but only slightly. It has been found that water absorption increases by approximately 20 %.