Currently, in Ukraine and abroad for the construction of high-rise buildings and structures using pipe-like structures. Wide application of pipe concrete columns is due to their high carrying capacity at relatively smaller overall dimensions due to the blocking of cracking in concrete by a steel clasp. The advantages of concrete columns should include more simplified conditions of technology of manufacturing and installation on their basis of bearing structures of floor covering. Piping constructions consist of steel shells and concrete core. Since the steel pipe mainly provides the bearing capacity of the concrete column, its failure or reduction of stiffness, which is characteristic of the fire under the influence of its thermal factors, leads to destruction. Investigation of fire resistance of concrete structures, which are not protected by flame retardant coatings, showed that a steel clasp during a fire after 15 minutes is heated to a critical temperature of 500 ° C.The use of flame retardant coatings is an effective method of fire protection of concrete constructions, which prevents the rapid heating of steel welds and provides a normalized fire resistance limit for such structures. In this work, studies were carried out on the effectiveness of fire protection of concrete columns with different types of fire-retardant materials - mineral wool slabs, special flame retardants and flame-retardant coatings. For fire protection mineral wool materials were used ROCKWOOL plates of the series "Conlit SL150". Mineral wool plates "Conlit SL 150" consist of fibers of rocks of a basalt group, they can withstand, without melting, temperature more than 1000 ° С. The silica-based adhesive "Conlit Glue" can withstand temperatures above 900 ° C, has good adhesion when bonding Conlit SL 150 mineral wool slabs with protective structures. From the second type of fire-retardant materials, the fire-proof composition "Naktresk" was chosen on the basis of gypsum. The coating is formed in the process due to hardening of the mixture on protected surfaces. The third type of flame retardant materials is the flame-retardant intumessent coating "Pyro-Safe Flammoplast SP-A2".It has been established that with the use of fire protection systems on the basis of mineral wool plates "Conlit SL150" and fire retardant "Nutresc", the fire resistance class of reinforced concrete columns increases from R 15 to R 180. The fire protection system on the basis of the painted paint "Pyro-Safe Flammoplast SP-A2" »Increases fire resistance from R 15 to R 75
The analysis of technical and operational properties of dry fire prevention devices was carried out. The properties of waste zeolite catalysts such as "Tseosor 5A" and their behavior in high temperature conditions were investigated. The efficiency of the use of waste zeolite catalyst "Tseosor 5A " as a flame retardant element of dry fire prevention devices was proved. The critical nozzle diameters of the fire prevention devices were calculated for various vapor-gas-air mixtures.
Problem. Religious buildings with a large number of people are fire hazardous. In total, there are 17,407 religious buildings in Ukraine. Out of them, approximately 3,000 are highly fire hazardous wooden buildings.The fire danger feature of religious buildings is open fire usage: candles, torches, lamps, underground rooms with complex planning, lack of ventilation systems. Besides, ancient religious buildings are mostly built using wooden materials. Fires occuring there are resonant, causing material and spiritual damage to the state and society. On average, about 20 fires occur each year in religious buildings, including wooden temples of historical heritage.Рurpose. Fire analysis in religious buildings in Ukraine and their occurrence causes; fire safety of religious buildings research.Preventive measures for religious building fire safety in Ukraine are prioritised by state program for emergency response. The State Emergency Service of Ukraine constantly monitors compliance with fire safety standards, which includes regular facilities inspections, personnel training control to prevent fires and reduce the consequences of fires, development, implementation, and control of technical methods of safety.Research methods. To achieve this goal, further methods were used: historical, systemic, theoretical generalization, abstract, logical, analysis, synthesis, comparative, and statistical methods.The main results. The most common shortcomings in religious building fire protection are the lack or malfunction of automatic fire alarms, power grid requirement non-compliance with the rules of the power grid, improper facility provision of with primary fire extinguishers, lack of lightning and water supplies for firefighting. In most buildings, wooden structures are not treated with refractory mortar.Fire causes and ways to prevent and improve fire safety are analyzed, namely: fire protection of religious building wooden elements, dome space fire extinguishing systems, fire alarm systems, lightning protection, safe people’s evacuation, candlesticks installation on non-combustible surfaces, primary fire extinguishing equipment, fire condition qualitative inspection of the of the heritage building, etc.Conclusions. After service, buildings must be completely deenergized, lighted candles and open fires must not be left unattended in the church. In religious buildings, it is necessary to carry out fire protection of wooden elements constructions, to install fire extinguishing systems in domed space, fire alarm system, lightning protection, to watch serviceability of electric networks. Rules of fire safety requirements for religious buildings are aimed at solving an important task - religious buildings safety. Unfortunately, due to lack of funds, the most important requirements are not implemented to improve fire safety.
The mathematical modeling of the thermo-stressed state of pipe-concrete structures under conditions of stationary thermal conductivity is carried out. During the study, the most common structural type of TBC was selected and mathematical models of the stress-strain state of TBA under heating conditions were taken into account, taking into account their geometric dimensions and thermophysical characteristics of metal and concrete. The main feature of the TBC study is that the heat exchange in the structure, as well as the corresponding force response, are investigated independently of each other, whereas the problem of fire resistance should be posed as a classical problem of elasticity, taking into account the mutual influence of temperature and mechanical stresses. In two-layer structures (concrete - metal), the largest radial stresses that occur in concrete work in tension. Tensile stresses occur in the thickness of the outer tube. The stresses occurring on the inner surface of the steel sleeve coincide with the stresses in the concrete. When approaching the outer surface, they decrease and on the surface r = R2 equal to zero. In the case where the coefficients of linear extension αt (i = 1, 2) are equal to each other, the maximum tensile stresses are reduced within 0≤r≤R1 .; if νi (i = 1, 2) within 0≤ r≤R2, the stresses will also decrease. Axial stresses work on compression. They reach maximum value in the outer shell. For equal values αt (1) = αt (2), the magnitude of the stresses does not change, and at ν1 = ν2 the stresses in the metal will decrease. Ring stresses in the region 0≤ r≤R1 are tensile stresses and in the region R1≤ r≤R2 are compression stresses, and the compression stresses are greater than the tensile stresses in concrete. For αt (1) = αt (2), the stresses in the concrete decrease and for ν1 = ν2.
Polyfunctional protective coatings based on filled polysiloxane compositions are technological and can be used to increase the fire resistance of metal structural materials due to high thermomechanical properties, which are determined by stable structural and phase composition. The influence of protective coatings on the basis of polysiloxane-filled oxide components on fire resistance of aluminum alloys is investigated in the work. The choice of the initial compositions for fire protection coatings was carried out with the aim of obtaining of expanded heat-insulating heatresistant layer on the surface of an aluminum alloy at temperatures of 473 K and higher. The methods of physico-chemical analysis have established that when heated more than 473 K as a result of thermo oxidative degradation of polysiloxane with the release of gaseous products, there is an expanding coating with the formation of a fire-proof porous heat-insulating layer on the surface of an aluminum alloy. The coefficient of expanding the coating is within the range of 9.8 ... 12.4. The reliability of the use of physicochemical criteria when choosing the component composition of the coating and the effectiveness of the fire protection function is estimated from the results of the test on the aluminum alloy AMG6 and on the model of its thermal conductivity. 20 Пожежна безпека, №34, 2019 A model of thermal conductivity of a protective coating is proposed, which consists of a layer that limits heat transfer through a two-layer wall. When exposed to the aluminum plate of the heat flow, it is heated to the depth of the coating, which leads to its expanding and the formation of a thermal barrier. The dynamics of temperature distribution during a fire on the protective coating of an aluminum alloy is predicted by simulating the heat transfer process in a homogeneous solid by a mathematical model. The theoretical and practical researches have established the dependence of the parameter of heating the protected aluminum alloy to the critical temperature, depending on the thickness of the coating. The presence on the surface of a protected alloy coating, based on the filled polysiloxane, changes the process of heat transfer to its surface, which increases the fire resistance of the structure by 3 ...4 times.
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