Experimental study on examining the fire load of a small compartment

In Hungary a lot of people live in condominiums or in block of flats where fire often occurs despite of precise design and effective fire protection arrangements. This means a hazard for the people living there, for the building constructions and also for the environment. A deeper knowledge of the burning process and examining the negative effects of fire load on building constructions with scientific methods are actual questions nowadays. In order to get to know the phenomena more accurately, fire spread in a bedroom was modeled and numerical simulation was carried out, which is presented in this paper in detail. These experiences may help increasing the fire safety and preventing fires in apartments. The simulations were carried out considering the characteristics of the Hungarian architecture.

Research into the physical and chemical properties of fire-retardant materials of structural elements of trucks running on gas engine fuel with the aim of increasing their fire-retardant efficiency

The fire load is an integral part of the fire hazard definition. Reducing this load is one of directions to fight fires in transport. To study the physicochemical processes and thermal effects occurring as a result of thermal decomposition of wood fire-proofed by retardants like BAN, OK-GF, OK-DS (OK-GFM), SPAD-0 and their chemical compositions, we used the methods of differential thermal analysis, thermogravimetry, and derivative thermogravimetry. In addition, to study the intensity of physicochemical combustion processes, tests to control changes in woodwork masses and temperature at the top of pipe depending on the duration of combustion of the samples and the consumption of fire retardants were conducted. Fire retardant compositions like OK-GF, OK-DS, Pirilax biopyrene at the consumption of 0.1 kg / m2 ensure flame and combustion resistance of the wood. The analysis of the research results confirmed the possibility of assigning to wood structures of a lorry’s body of the group 1 of flame and combustion resistance. Using the above fire retardants and their compositions in the treatment of lodgment elements and runners significantly affects the possibility and duration of the combustion process of a lorry. This was tested by means of an artificial fire source method (without chemical treatment, the burning time does not exceed 50 minutes). This significantly improves post-collision safety of vehicles with an increased fire load in terms of fire resistance because of using the natural gas as a motor fuel.

Simulation of scenarios for the development of a fire in a shopping and entertainment center

The paper analyzes fires in the Russian Federation, including in shopping and entertainment centers. Objects with a mass stay of people are investigated on the example of the shopping entertainment center Passage "Solnechny Rai" in Voronezh. As a result of the analysis carried out on the study of objects with a massive presence of people, in our case, at the alleged object of extinguishing a fire and conducting an ACR, at the time of the fire there were more than 50 people, one way or another in comparison even with night time when there are no people at the object , the object refers to objects with a mass presence of people. Forecasting the development of the fire was carried out for the shopping and entertainment center Passage "Solnechny Rai". Simulation of two scenarios of fire development with the most dangerous zones of fire occurrence has been carried out. According to the first scenario of a fire in the premises of the Perekrestok store located on the ground floor, in the event of a fire in the store, the greatest amount of manpower and resources will be required, since this facility has the highest fire load, storage of a large amount of goods. According to the second scenario, a fire breaks out in a retail space located on the third floor of the building of the “Solnechny Rai” Passage shopping and entertainment center. As a result of a fire, adjacent rooms and higher floors are quickly filled with combustion products, which will lead to the impossible evacuation of people by their own forces. For the considered shopping and entertainment center, recommendations have been developed for organizing rescue operations.

Reliable assumptions for structural fire design of steel car parks

PurposeThis study aims to analyze and discuss the key design assumptions needed for design of car parks in steel, to highlight the impact that the increased fire loads introduced by modern cars and changes in the fire dynamics have on the design, such as fire spread leading to non-localized fires.Design/methodology/approachIn particular, a reliable fire load density to be used for structural design of car park structures is assessed, based on investigations of the fire loads of modern cars. Based on knowledge of fire load and fire performance of cars, the consequences on the fire safety design of steel structures are presented.FindingsDesign recommendation about fire load density and fire protection of common steel profiles are given. Finally, the proposed design is compared with a design practice that has been applied in many instances for car parks constructed with unprotected steel, and recommendations for a reliable design process are provided.Originality/valueNumerous car park buildings have recently been designed of steel structures without passive or active fire protection. The key assumptions that makes possible such design are local fire scenarios, outdated values of the car fire load and utilization of the ultimate steel strength. This paper identifies the shortcomings of such key assumptions, indicating the need for revisiting the methods and possibly even checking the analyses carried out for some already-built car parks.

About the fire hazard of transport hydrotunnels

В статье рассмотрена достаточно новая проблема, связанная с появлением и развитием перспективной транспортной инфраструктуры – гидротоннелей. Показано, что ввиду большой пожарной нагрузки, которую представляют собой проходящие по гидротоннелю суда (пассажирские, сухогрузы, контейнеровозы. танкеры) возможно возникновение пожаров, угрожающих как самим судам и их экипажам, так и конструкции гидротоннеля – обрушение его свода из-за экстремальных тепловых нагрузок. Проведено компьютерное моделирование с использованием полевой модели пожара, подтвердившее факт быстрого роста температуры и концентрации токсичных продуктов горения, а также «тоннельный эффект» - прохождение высокотемпературного потока газов к одному из торцов тоннеля. Даны предложения по действиям персонала судов в гидротоннеле и пожарных кораблей по тушению пожара и спасению людей. Показана необходимость оборудования некоторых гидротоннелей дренчерными системами пожаротушения. Сделан вывод о необходимости дальнейших исследований в части пожарной безопасности транспортных гидротоннелей и разработке соответствующего нормативного документа. The article considers a fairly new problem associated with the emergence and development of a promising transport infrastructure – hydrotunnels. It is shown that due to the large fire load, which is represented by vessels passing through the hydrotunnel (passenger, dry cargo, container ships. tankers) there may be fires that threaten both the ships themselves and their crews, and the structure of the hydrotunnel – the collapse of its arch due to extreme thermal loads. A computer simulation was carried out using a field model of a fire, which confirmed the fact of a rapid increase in temperature and concentration of toxic combustion products, as well as the "tunnel effect" - the passage of a high-temperature gas flow to one of the ends of the tunnel. Suggestions are given on the actions of the personnel of vessels in the hydrotunnel and fire ships to extinguish the fire and rescue people. The necessity of equipping some hydrotunnels with drencher fire extinguishing systems is shown. The conclusion is made about the need for further research in terms of fire safety of transport hydraulic tunnels and the development of an appropriate regulatory document.

RESEARCH TEMPERATURES OF IGNITION AND SELF-IGNITION OF COTTON AND POLYESTER FABRICS

Formulation of the problem. Most of the fabrics used in the technological processes of garment enterprises are classified as combustible materials and are part of the fire load, which threatens the outbreak and rapid spread of fires in the premises of garment factories. Therefore, it is important to study the indicators of the fire hazard of fabrics to identify the most dangerous of them, as well as to increase the efficiency of fire safety at sewing enterprises.The purpose of the work is to obtain the dependences of the values of ignition and self-ignition temperatures of cotton fabrics on the composition of cotton.Results. It was found that the crushed 100% cotton fabric flamed best, and the worst − solid polyester as a fabric without cotton. The lowest value of the temperature at which ignition was observed was 215°C for cotton (100%, shredded fabric), and if this value is reduced - there were failures, which are caused in particular by the fact that at lower temperatures flammable vapours are no formed in concentrations sufficient for combustion. It was found that the ignition / spontaneous combustion temperatures for a solid sample of the fabric with a composition of 100% cotton are 235°C/420°C, and for a solid sample of the fabric with a composition of 100% polyester − 360°C/500°C, respectively. Ignition / spontaneous com-bustion temperatures for finely divided fabrics are 8,5%/4,78% (cotton fabric) and 2.8%/6% (polyester) lower than the values obtained for whole fabrics.Results. According to the results of the analysis of the most common fabrics (table 1) used in garment enterprises. Identified that the biggest fire hazard is inherent containing cotton. The lowest ignition temperature is observed for cotton (100% shredded fabric) and is 215°C, which is 1,63 times less than the ignition temperature of polyester (0% cotton, shredded fabric). The lowest self-ignition temperature is also observed for cotton (100% shredded fabric) and is 400°C, which is 1,18 less than the self-ignition temperature of polyester (0% cotton, shredded fabric).

Analysis of Concrete-Filled Steel Tube Reinforced Concrete Column-Steel Reinforced Concrete Beam Plane Frame Structure Subjected to Fire

The ABAQUS finite-element analysis platform was used to understand the mechanical behavior of concrete-filled steel tube reinforced concrete (CFSTRC) columns and steel reinforced concrete (SRC) beam plane frames under fire conditions. Thermal parameters and mechanical constitutive model of steel and concrete materials were reasonably selected, the correct boundary conditions were chosen, and a numerical model for the thermal mechanical coupling of CFSTRC columns and SRC beam plane frame structure was established. The finite-element model was verified from related experimental test results. The failure modes, deformation, and internal force distribution of the CFSTRC column and SRC beam plane frames were analyzed under ISO-834 standard fire conditions and with an external load. The influence of beam and column fire-load ratio on the fire resistance of the frame structure was established, and the fire-resistance differences between the plane frame structures and columns were compared. The CFSTRC column-steel reinforced concrete beam plane frame may undergo beam failure or the column and beam may fail simultaneously. The frame structure fire-resistance decreased with an increase of column and beam fire-load ratio. The column and beam fire-load ratio influence the fire resistance of the frames significantly. In this numerical example, the fire resistance of the frames is less than the single columns. It is suggested that the fire resistance of the frame structure should be considered when a fire-resistant structural engineering design is carried out.

Experimental study on the fire resistance of concrete filled steel tube reinforced concrete (CFSTRC) column-RC beam frames

To reveal the temperature characteristics and mechanical properties of frame structures with concrete filled steel tube reinforced concrete (CFSTRC) columns under fire, the fire resistance of four planar frames consisting of CFSTRC columns and reinforced concrete (RC) beams subjected to ISO-834 standard fire was tested in this study. The test parameters included the column fire load ratio, beam fire load ratio, and beam-to-column linear stiffness ratio. In the test, the temperatures of the column, beam, and slab cross-sections in the joint and nonjoint zones were measured, and the fire resistance, beam and column deformation curves, and failure modes of the frame were investigated. The experimental results showed that the concrete volume was the main factor affecting the temperature distribution on each typical cross-section of the frame: the temperatures at the measuring points of the beam and column in the joint zone were significantly lower than the temperatures at the corresponding points in the nonjoint zone, and the concrete outside the steel tube significantly slowed the propagation of temperature to the steel tube and its concrete core. Hence, there was only a small loss of the bearing capacity of steel tube and the core concrete inside the steel tube. The column fire load ratio, beam fire load ratio, and beam-to-column linear stiffness ratio have obvious influences on the fire resistance: the larger the column fire load ratio or beam fire load ratio, the smaller the fire resistance; and the larger the beam-to-column linear stiffness ratio, the larger the fire resistance.