CHEMICAL AND MYCOLOGICAL METHOD USED TO STUDY TIMBER

Abstract

Introduction. Preservation of lingo-carbohydrate complex determines the strength and durability of wooden constructions. The issue of wood preservation is of utmost practical value. There is an extensive academic discussion of the approaches to the issue. The activity of timber destroying fungi is defined by the number of viable spores per surface unit. The work aims to de-velop chemical and mycological timber research method in order to evaluate the condition of wooden architecture monuments and provide well-grounded prognosis of their durability. Materials and methods. The research was carried out using the samples brought from the Kremlin of Rostov the Great, Kizhi State Open-Air Museum of History, Moscow Small Vlasyevsky lane house. The service life of these buildings and constructions is 100, 150, 350, 400 and 1,000 years. The developed chemical and mycological method of wood research implies quantitative estimation of viable fungi spores per 1 cm2 of the surface under study along with the definition of the species composition of the fungi community supported with physical and chemical definition of component changes in lingo-carbohydrate wooden complex. Wood structure was examined by electronic microscopy method. Conclusion. As a result of the carried out research it was revealed that the destruction of wood begins when the quantity of viable fungi spores amounts to 80 spores per cm2. When the concentration of viable spores amounts to 180 spores per cm2 it results in destruction of approximately 40-50 % of cellulose, thus wood loses 30 % strength. It was evidenced from microscopic research that wood destruction begins from the surface. Infrared spectroscopic analysis revealed that on IR spectrum of partially destructed wood the absorption spectrum increases within  1,730 cm-1 and 1650 cm-1, which proves that there are carbonyl groups in the samples. The concentration of carbonyl groups increases in the process of biocorrosion of wood. Thus, chemical and mycological wood research method provides evidence of the wood condition and rationale for the possibility of long-term use of these wooden constructions.