The dissertation research investigates the influence of impregnating fire-protective substances on the fire hazard indicators of wooden building structures when replacing a fire retardant during repeated fire-protective impregnation, and also reveals the patterns of influence of fire hazard factors when replacing impregnating fire-protective substances on their fire-protective efficiency.
The introduction provides a general description of the dissertation, justifies the relevance of the research topic, formulates the goal and objectives of the study, defines the object and subject of the study, presents the scientific novelty and practical significance of the results obtained.
In the first section, based on the analysis of statistical data, the trend of involving representatives of territorial divisions of the State Emergency Service in quality checks of fire protection work on wooden building structures is outlined, which indicates an increase in the number of works of this type performed, as well as the interest of customers of fire-protective impregnation in proper fire protection, which ensures the fire safety of the facility.
According to the results of analytical studies of the conclusions of the commissions for checking the fire protection of wooden building structures, a relationship was found between inadequate fire protection of wooden building structures and fire protection solutions. Namely, in most cases, surface impregnation was carried out with a different fire protection solution than the previous one.
In the second section, based on the analysis of existing methods of testing the fire protection of wooden building structures in Ukraine, the advantages and disadvantages of each of the methods of quality control of fire protection treatment were identified.
According to the results of the analytical study, significant disadvantages of the express method were identified, due to technically low accuracy and moral obsolescence, which is manifested in the possibility of determining only the IInd group of fire protection, technical difficulties in selecting samples and the lack of clear test criteria.
It was determined that the accelerated method for determining fire-retardant properties is the most effective and objective, but is limited exclusively to laboratory conditions, and the methods for controlling the suitability of impregnated wood are the most modern for checking the quality of fire-retardant impregnation directly at operated facilities.
Based on the analysis, the feasibility of using the accelerated method for determining fire-retardant properties, the method of controlling by ignition temperature and the method of controlling by the sign of spontaneous combustion for further research is justified as the most effective and optimal methods.
In the third section, experimental studies are conducted with the manufacture of samples that are subjected to repeated fire-retardant treatment with the replacement of the fire-retardant. The conducted studies give reason to assert that the replacement of the fire-retardant affects the main indicators of fire-retardant efficiency, such as: mass loss, signs of spontaneous combustion and ignition temperature. In general, the dynamics of changes in the main indicators demonstrate their deterioration.
Based on the results obtained, it can be assumed that fire retardants may not be compatible when re-fire retardant treatment is carried out, as they lead to a decrease in fire retardant efficiency.
In the fourth section, using X-ray fluorescence analysis and chemical analysis methods, it was investigated that the most common components of fire retardants are: diammonium phosphate, orthophosphoric acid and urea.
Based on the identified components, the optimal ratio of the composition of the fire retardant was developed using the full-factorial experiment method, which provides fire protection of wooden building structures when replacing fire retardants, namely: diammonium phosphate - 4%, urea - 6%, phosphoric acid 12%.
The regularity of the influence of the percentage mass value of phosphoric acid, urea and diammonium phosphate on the fire protection of wooden building structures has been established, namely for the ignition temperature and mass loss.
Using modern statistical methods, the reproducibility of the experimental results has been ensured, and the general convergence of each individual experiment has been confirmed. At the same time, the absolute deviations between the averaged research results do not exceed 1.81% for the mass loss indicator, and 0.49% for the ignition temperature.
A fire retardant has been developed and certified - an impregnating fire-bioprotective substance for wood and cellulose-containing materials "FIRE BREAK".
