Корозійна стійкість полімерсилікатних композицій для вторинного захисту будівельних конструкцій

This article investigates the long-term corrosion resistance and determines the predicted service life of organosilicate composites for secondary corrosion protection of building structures. The protective system consists of a polymer component (polyisocyanate and oligoether acrylate) and a silicate component (soluble sodium silicate and an active mineral component). The chemistry of the interaction between isocyanate groups and capillary moisture in the substrate has been substantiated, eliminating the need for special preparation of a damp substrate. It has been established that the developed compositions are highly effective in liquid aggressive media. The kinetics of changes in compressive strength and mass of the samples over test periods of up to 6 years have been analyzed. It was determined that the systems exhibit maximum durability in solutions of mineral salts (5% NaCl, 5% MgSO₄, 10% sea salt), where the chemical stability coefficient remains consistently within the range of 0.94–1.17. The differentiated nature of material failure in alkaline environments was investigated. The undeniable superiority of composition No. 1 has been demonstrated; it retains its integrity in a 25% alkali solution due to its ability to relax internal mechanical stresses, whereas other compositions undergo destructive cracking. The inverse nature of sulfate corrosion was revealed, whereby in a 25% H₂SO₄ solution, the instantaneous reaction causes pore blockage and additional structural densification of the surface (K_x = 1.13–1.15), while in a 3% solution, a volumetric decrease in strength is observed. The stability limits of the systems in hydrochloric and nitric acids have been determined. Recommendations are proposed for a comprehensive assessment of the protective capacity of materials—directly in the form of single-, double-, or multi-layer coatings on concrete substrate specimens—to optimize the engineering protection parameters of reinforced concrete infrastructure facilities for industrial use