scholarly journals Fire resistance of lightweight steel-concrete slab panels under high-temperature exposure

2021 ◽  
Vol 264 ◽  
pp. 02003
Author(s):  
Vladimir Rybakov ◽  
Anatoly Seliverstov ◽  
Oybek Vakhidov

Lightweight steel concrete structures (LSCS) - an innovative energy-efficient building structure type that can be used both as load-bearing and as enclosing one. They consist of profiled steel - usually galvanized and cold-bent - filled with a monolithic foam concrete with a 400kg/m3 density and with fiber cement sheets sheathing. These structures can be used in industrial and civil buildings as internal and external bearing and enclosing wall structures and as slabs, energy-efficient roof covering. According to the LSCS production method, prefabricated panels (walls and slabs) and building site performed constructions are distinguished. The paper presents the testing results with the aim to determine the fire resistance limit of a slab panel fragment by bearing capacity (R), loss of integrity (E), loss of heat insulating capability (I) and fire hazard class. Two samples of a slab panel fragment were selected for the fire resistance high-temperature tests. The actual fire resistance limit of samples of the slab panel fragment is at least REI 60 with a uniformly distributed load 4 kN/m2.

Author(s):  
L.P. Vogman ◽  
◽  
A.V. Iliychev ◽  
E.E. Prostov ◽  
D.V. Dolgikh ◽  
...  

On the basis of theory of stationary thermal explosion of A.D. Frank-Kamenetsky, depending on the temperature of the critical size of the ammonium nitrate embankment, the calculations were performed, which show that it can be stored in the large volumes at the temperatures up to 30 °C. On the contrary, at the temperatures above 100 °C (for example, at 200 °C), the decomposition of nitrate occurs with acceleration and can lead to an explosion. Based on the studies performed, it is shown that the changes and additions to the fire safety requirements for ammonium nitrate storage in the buildings and structures should be determined by the requirements for fire resistance of buildings (at least II degree of fire resistance), for the purity of the product and its packaging, for the exclusion of contacts with organic substances and materials, storage conditions. Additional fire safety requirements were developed for inclusion in the normative document regarding ammonium nitrate storage. Ammonium nitrate is allowed to be stored in one-story warehouse buildings of at least II degree of fire resistance, structural fire hazard class C0. The floor area within the fire compartment should not exceed 10 500 m2. Between the fire-fighting walls of the 1st type, it is allowed to store no more than 25 000 tons of nitrite in bulk or in the special bags, as well as in the soft specialized containers for bulk products in accordance with GOST 2—2013.The conditions for placing ammonium nitrate in the stacks should be accepted in accordance with the requirements of SP 92.13330.2012. Temperature in the storage room of ammonium nitrate should not exceed 30 °C with a relative humidity of not more than 60 %. Warehouses for storing ammonium nitrate should be equipped with general exchange supply and exhaust and (or) emergency ventilation, in order to exclude the formation of a fire and explosion hazardous environment in the room during the decomposition of ammonium nitrate. Warehouses for storing ammonium nitrate in an amount of not more than 5 thousand tons may be separated from other premises, including from the warehouses for fertilizers and pesticides, by solid (without openings) type 2 fire walls.


2018 ◽  
Vol 245 ◽  
pp. 08008 ◽  
Author(s):  
Vladimir Rybakov ◽  
Anatoly Seliverstov ◽  
Denis Petrov ◽  
Andrei Smirnov ◽  
Anna Volkova

Lightweight steel concrete structures (LSCS) - an innovative building structure type that can be used both as load-bearing and as enclosing one. They consist of profiled steel usually galvanized and cold-bent - filled with a monolithic foam concrete with a 200kg/m3 density, and with fiber cement sheets sheathing. These structures can be used in industrial and civil buildings as internal and external bearing and enclosing wall structures, and as slabs. According to the LSCS production method, prefabricated panels (walls and slabs) and building site performed constructions are distinguished. The article presents the LSCS subspecies, representing slabs panels made of galvanized profiled steel, density medium grade D400 monolithic foam concrete and sheets “Steklotsem” sheathing, bearing capacity experimental studies results. The paper confirms that such panels can be used in civil buildings and withstand the appropriate load, regulated by the current codes and rules. Moreover, it has been experimentally proved that the foam concrete, despite its own extremely low strength class, actually includes in the operation, preventing such effects as stability local loss, crushing and profile steel elements cross-section warping and increases the slabs overall load capacity by 20-25%.


Author(s):  
Soo-yeon Seo ◽  
Jong-wook Lim ◽  
Su-hyun Jeong

AbstractTo figure out the change in the reinforcing effect of FRP system used for the retrofit of RC beam when it is exposed to high temperature, it is required to evaluate not only the behavior of the entire beam, but also the bond performance at anchorage zone through a bond test according to the increase of external temperature. Moreover, the study to find various fire-protection methods is necessary to prevent the epoxy from reaching the critical temperature during an exposure to high temperature. In this manner, the fire-resistance performances of externally bonded (EB) FRP and near-surface-mounted (NSM) FRP to concrete block were evaluated by high-temperature exposure tests after performing a fire-protection on the surface in this paper. Board-type insulation with mortar was considered for the fire-protection of FRP system. After the fire-protection of the FRPs bonded to concrete blocks, an increasing exposure temperature was applied to the specimens with keeping a constant shear bond stress between concrete and the FRP. Based on the result, the temperature when the bond strength of the FRP disappears was evaluated. In addition, a finite element analysis was performed to find a proper method for predicting the temperature variation of the epoxy which is fire-protected with board-type insulation during the increase of external temperature. As a result of the test, despite the same fire-protection, NSM specimens were able to resist 1.54–2.08 times higher temperature than EB specimens. In the design of fire-protection of FRP system with the board-type insulation, it is necessary to consider the transfer from sides as well as the face with FRP. If there is no insulation of FP boards on the sides, the epoxy easily reaches its critical temperature by the heat penetrated to the sides, and increasing the thickness of the FP board alone for the face with FRP does not increase the fire-resistance capacity. As a result of the FE analysis, the temperature variation at epoxy can be predicted using the analytical approach with the proper thermal properties of FP mortar and board.


2020 ◽  
Vol 316 ◽  
pp. 02001
Author(s):  
Jing Sheng ◽  
Aamir Sohail ◽  
Mengguang Wang ◽  
Zhimin Wang

In order to realize the need for lightweight automobiles through replacing steel with plastics, the research and development of the plastic clutch pump body based on the friction welding was carried out. For the clutch pump body connected by friction welding process between the upper pump body and the lower pump body, the technical requirements of pressure 14 MPa and durability (high temperature 7.0 × 104 times, room temperature 7.0 × 105) are required. The structure type of the upper and lower pump bodies of the end face welding type was proposed. Through the static analysis of the pump body and weld and the mechanical analysis under the working condition, the structure of the clutch pump body (upper and lower pump body) was determined. According to the established welding process, the pressure of the clutch pump body is more than 15 MPa, and the number of high-temperature durable circulation and the number of room temperature durable circulation also reached 7.2×104 and 7.3×105 times respectively. The results show that the structural design of a clutch pump body meets the design requirements.


2020 ◽  
Vol 68 (4) ◽  
pp. 14-17
Author(s):  
Franka Žuvela Bošnjak ◽  
Sandra Flinčec Grgac ◽  
Suzana Mihanović

The quality and properties of fire resistance are crucial to the selection of leather for the production of protective fire fighting boots, which has a primarily protective role. During fire extinguishing it is exposed to extremely high and low temperatures, chemicals (acids and alkalis), mechanical loads, etc. The properties of fire resistance were tested on two samples of bovine leather (BL1, BL2). Burn resistance test has been carried out in accordance with the requirements of the technical standards for the burn resistance test: HRN EN ISO 15090: 2012, t, 7.3 - Firefighters and rescue services. The mentioned two samples were individually tested according to HRN EN ISO 15025: 2003. The test procedure was carried out by the "Flame Expansion Testing Method". Moreover, in this research used Microscale Combustion Calorimeter (MCC) Govmark, UK because that was designed for produce the maximum heating rate capability similarly the heating rates in fires and give as a lot of flammability parameters. The analysis of physicochemical properties of samples was performed using Fourier transform infrared (FTIR) spectroscopy. The surface morphology of the samples was studied using a Field Emission Scanning Electron Microscopy (FE-SEM). The measurement of the above samples on MCC was performed according to ASTM D7309. From the obtained HRR results, it is evident that BL1 sample has a better thermal stability than the BL2 sample.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xiujuan Li ◽  
Ruisong Guo ◽  
Xiaodong Qian

Under high temperature, aqueous film forming foam extinguishing agent has poor flame retardancy and low fire efficiency. In order to solve this problem, talc was introduced into foam to form composite foam. The fire resistance and fire extinguishing properties of the composite foam were studied. The results showed that talc composite foam had good flame retardant resistance. when the concentration of talc reached 40 g/100 ml, the 50% liquid separation time of the composite foam was 21.1 min. The fuel burning in the anti burning tank did not ignite the gasoline in the oil pan, and burned out at 51.5 min. It was related to the structure of composite foam and the properties of talc. Due to the introduction of talc, the viscosity of the composite foam increased. The network structure of composite foam was important to the improved stability of foam. Talc powder formed a dense layer covering the oil surface, which effectively isolated the oil from the air.


Fire Safety ◽  
2019 ◽  
pp. 5-9
Author(s):  
O. I. Bashynskiy ◽  
M. Z. Peleshko ◽  
T. G. Berezhanskiy

The article is dedicated to the fire resistance limit of building structures of the objects for the storage of flammable and combustible liquids. Today, oil stores are very important elements of the oil supply system in Ukraine. The analysis of literary sources has shown that fires in oil stores cause extra fire hazard of surrounding objects. Increasing of their scales requires further improvement of fire safety measures during planning and using of oil stores. Fires in such buildings are tricky and large; they cause great harm and often lead to the death of people; their liquidation is very difficult. Theoretical calculations shown that the collapse of structures of the packaged oil stores and, as a result, significant material losses and the threat to people's life and health, were resulted from the incorrect selection of building structures and the discrepancy between the fire resistance of these structures and the applicable norms and requirements for such buildings. Fire Safety, №34, 2019 9 Fire resistance limit of the metal double-T pillar made of steel ВСт3пс4 (profile size number 30) was calculated in the article. Such constructions are used in oil stores. The obtained fire resistance limit of a metal double-T pillar is about 16 minutes (R 16). According to the normative documents for buildings of this type (the degree of fire resistance of the building – III), it should be 120 minutes (R 120). Even if the calculation method has an error due to the choice of another steel grade, objectively none of the double-T profiles from the assortment list would provide proper fire resistance limit.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1358-1362
Author(s):  
Jin Sheng Han ◽  
Hao Ran Liu ◽  
Shu Ping Cong

The fire resistance of concrete filled steel tubular column is usually obtained by the numerical analysis method, which is difficult to operate and not convenient in the actual civil engineering. So it is necessary to study the simplified calculation method. A large number of numerical simulation results of the temperature distribution of the section and the bearing capacity at high temperature of the concrete filled steel tubular columns are analyzed. The influences of secondary parameters are simplified. The simplified calculation method at 150 min and 180 min for the bearing capacity at high temperature of concrete filled steel tubular columns subjected to axial compression and fire is presented on the basis of comprehensive analysis of the numerical calculation results. The calculation results can be used as the basis to judge the fire resistance. It is shown by the comparison with the experimental results that the precision of the simplified calculation method can meet the requirements of engineering application.


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