STUDY OF THE COMPOSITION OF SUBSTANCES FOR FIRE PROTECTION OF WOODEN BUILDING STRUCTURES IN THE CONTEXT OF REPLACING FIRE-RETARDANT AGENTS

Introduction. Thousands of fires occur every year at facilities of various forms of ownership, where state supervision (control) measures are carried out in the field of technogenic and fire safety. In a significant number of cases, fires occur in buildings in which, according to the Fire Safety Rules in Ukraine, wooden building structures are subject to fire protection. Fire protection ensures a reduction in fire hazard indicators, in particular combustibility, flammability, flame spread, etc.According to the Fire Protection Rules for Wood, it is determined that the main criterion is the fire protection efficiency group, which is characterized by determining the percentage of mass loss of wood subjected to fire protection after testing. Fire protection methods such as fire protection impregnation and treatment are characteristic of wooden building structures.Fire protection impregnation itself has become widely used in Ukraine. When analyzing the quality of fire protection by impregnation, it was found that when performing repeated fire protection work using a product different from that used during the previous impregnation, there is a loss of fire protection efficiency. The experiments conducted confirmed this hypothesis and prompted the isolation of this direction for further research.The purpose of the work is to reveal the patterns of the influence of the ratio of the composition of the fire retardant on ensuring fire protection of wooden building structures when replacing fire retardants.Methods. As part of the scientific work, analytical studies of the components of impregnating fire and bioprotective substances were conducted. Individual substances were studied using chemical and X-ray fluorescence analysis methods. Based on the identified components, as well as taking into account the results of previous studies, a full-factorial experiment was planned and implemented.Results. A full-factorial experiment was conducted, within the framework of which key factors and their levels of variation were determined, which ensured the construction of a mathematical model. Based on this model, an experimental matrix was constructed. Eight experimental studies were carried out according to the specified methods, numerical values of mass loss and ignition temperature were obtained, which made it possible to calculate regression coefficients.Using X-ray fluorescence analysis and chemical analysis methods, it was established that the most common components of fire-retardant substances are diammonium phosphate, orthophosphoric acid and urea. Based on the specified components, the optimal ratio of the composition of the fire-retardant substance was developed using the full-factorial experiment method, which ensures fire protection of wooden building structures when replacing fire-retardant agents. The pattern of the influence of the percentage mass value of phosphoric acid, urea and diammonium phosphate on the fire protection of wooden building structures - in particular, on the ignition temperature and mass loss - was established.Conclusion. Based on the analysis of experimental research data, regression equations and graphical dependencies, the ratio of the mass composition of the fire retardant substance that is capable of providing fire protection of wooden building structures when replacing fire retardants was determined, namely: diammonium phosphate – 4%, urea – 6%, phosphoric acid – 12%, water – 78%.