Increase of strength of partially destroyed wood of monuments of wooden architecture

Introduction. Monuments of wooden architecture - an invaluable part of the national culture, they reflect the originality and independence of the national architecture. The problem of preservation of monuments of wooden architecture with the passage of time is becoming increasingly important. Many monuments were burned; some were destroyed due to the loss of structural strength under the influence of humidity, biodestruction, etc. Materials and methods. The samples of partially destroyed wood of the Anglican Church of the city of Arkhangelsk, built in 1833, were studied. The samples were subjected to surface modification with the formation of a two-layer sandwich coating, the first layer of which was various phosphorus-containing flame retardants, and the second layer - polymer composites. As polymer composites, glue based on epoxy resin and polyurethane composition “Akvidur TT” were used. The reactive organophosphorus compounds, capable of forming covalent bonds with wood polymers in the surface layer of partially destroyed wood, were chosen as flame retardants. Modified samples were subjected to physicochemical studies to determine the strength, fire resistance, hydrophobicity. The strength of the modified samples was compared with the strength of the untreated samples of partially destroyed wood of the Anglican Church of Arkhangelsk. The appearance of covalent bonds between the wood and the modifier was determined by Fourier-transform spectroscopy. Results. Surface modification of the samples of the monument increased the strength of wood by 2-2.5 times, reduced water absorption by 3 times, reduced the loss of mass during combustion according to GOST 27484-87 to 5.0-6.4 %. Conclusions. The study solves the urgent problem of preservation of monuments of wooden architecture by increasing the strength of partially destroyed wood, as well as giving it fire resistance, hydrophobicity and biostability in carrying out restoration work.