The research into the heating effect of secondary steel structures, having no fire proofing, on the fire resistance of fireproof steel beams

2021 ◽  
Vol 30 (3) ◽  
pp. 16-30
Author(s):  
A. O. Vorosin ◽  
A. P. Parfenenko
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Fire Resistance ◽  
Fire Protection ◽  
Limit State ◽  
Steel Structures ◽  
Main Element ◽  
Steel Beams ◽  
Passive Fire Protection ◽  
Student Version

Introduction. The international practice of passive fire protection design, as well as some manufactures of fireproofing products recommend to apply fire proofing substances not only to the main element, whose fire resistance limit is standardized, but also to the elements that do not fall under any fire resistance standards. Various support brackets, pipeline supports (hereinafter — PS), etc. can serve as examples. They are not considered as bearing elements according to SP (Construction Regulations) 2.13130.2020, although they are connected to the structures that have fireproofing applied. It is recommended to apply fireproofing substances to such PS within the range of, at least, 450 mm from the point of attachment to the fireproof structure when the area of the PS cross section exceeds 3,000 mm2. No “supplementary” fireproofing is required by the Russian design and fire protection regulations.The subject of research. A change in the fire resistance limit of steel i-girders, caused by the PS heating, depends on the area of the PS cross section and the location of the point of its attachment.The goal. The goal of the research is to analyze the effect, produced by the area of the cross section and the point of attachment, on the fire resistance limit of fireproof steel i-girders in the course of heating.Materials and methods. ANSYS Workbench 2020 R2 (student version) was applied to perform the numerical simulation.Results. The simulation has shown that the PS, having no fireproofing, influences the fire resistance limit of fireproof structures.Conclusions. Currently available methods of analysis of the fire resistance of steel structures take no account of the fire resistance limit reduction, caused by the heating of the PS that has no fireproofing. The numerical simulation has shown that the fire proofing design must take account of the potential reduction in the fire resistance limit of fireproof structures, exposed to the heated PS that has no fire proofing. The further verification of the effect, produced by the PS, that has no fireproofing, on the time to the limit state of a fireproof steel i-girder requires fire tests and supplementary investigations to evaluate the influence of the PS on the heating of vertical fireproof constructions, including the case of the hydrocarbon fire mode.

Evaluation of fire-retardant effectiveness of coatings for steel structures

2020 ◽  
pp. 43-54
Author(s):  
Владимир Ильич Голованов ◽  
Андрей Владимирович Пехотиков ◽  
Владимир Валерьевич Павлов
Keyword(s):  
Thermal Conductivity ◽  
Fire Resistance ◽  
Fire Protection ◽  
Oil And Gas ◽  
Fire Retardant ◽  
Steel Structures ◽  
Building Structures ◽  
Load Bearing ◽  
Passive Fire Protection ◽  
Actual Fire

Представлены результаты анализа экспериментальной и аналитической оценки огнезащитной эффективности покрытий для стальных конструкций. Обобщены данные многолетних исследований по определению зависимостей от температуры таких теплофизических характеристик, как теплопроводность и теплоемкость. Разработана структурно-методологическая схема выбора огнезащитных покрытий для стальных конструкций в целях обеспечения нормативных требований по огнестойкости. Проведены экспериментальные исследования по определению огнезащитной эффективности терморасширяющихся покрытий на эпоксидной основе при воздействии температурного режима горения углеводородов. Рассмотрен вопрос о гармонизации методики экспериментальной оценки огнезащитной эффективности средств огнезащиты для стальных конструкций с действующими европейскими нормами. Установлены критерии выбора пассивной огнезащиты, зависящие от области применения способов огнезащиты. Steel structures have high strength, relative lightness and durability, but when exposed to high temperatures in a fire, they deform, lose stability and load-bearing capacity. The collapse of load-bearing steel structures can occur in 10-15 minutes after the fire start. The actual fire resistance limit of structures can be increased by using the active and passive fire protection systems. The use of the active system for increasing the actual fire resistance limit is not provided in the regulatory documents. Passive fire protection is a complex of technical solutions including the use of non-flammable materials and bulging compounds. It is also an integral part of the building structure that ensures the required fire resistance limit. Assessment of fire resistance of building structures of residential, public, warehouse and industrial buildings is carried out taking into account the temperature regime (cellulose) of a standard fire. At oil and gas, petrochemical enterprises as well as at oil production platforms fires can occur at combustion of various hydrocarbon fuels which are characterized by a rapid temperature increase to 1100 °C. In this case, in accordance with GOST R EN 1363-2-2014, the temperature regime of hydrocarbon combustion is used to assess the fire resistance of building structures. The fire-retardant effectiveness of fire protection means for steel structures is determined by the heating time of the standard I-shaped column without applying a static load on the sample to the average “critical” temperature of the steel of 500 °C. Materials used for fire protection of steel structures must have a good thermal insulation ability, which is estimated by the coefficient of thermal conductivity. When heated to high temperatures, the thermal conductivity coefficient of fire-resistant materials varies depending on their composition and temperature. Based on the analysis of research to determine the fire-retardant effectiveness of fire protection means for steel structures there was developed a structural and methodological scheme that allows to make a choice of fire protection. Currently, as a fire protection there are widely used intumescent paints and thermo-expandable coatings. Taking into account the lack of knowledge of the influence of long-term operation and a large number of other technological factors on the fire-retardant effectiveness of coatings of steel structures covered with intumescent paints, it would be right to limit the use of such type of fire protection for load-bearing structures contributing to the overall sustainability of buildings with a required fire resistance of R 30. For fire protection of steel structures of oil and gas facilities located in the open air, in severe climatic conditions and exposed to aggressive environments there is successfully used a thermo-expandable two-component epoxy-based coating. The analysis of experimental data showed that the use of epoxy-based coatings is suitable for metal structures in the open air. In closed rooms the epoxy intumescent coating should not be used because at high temperature in a fire it ignites with toxic combustion products release.

Design Study of Steel Structure Fire-Retardant Coatings under High Temperature (Fire) Conditions

2012 ◽  
Vol 594-597 ◽  
pp. 849-859
Author(s):  
Man Li Ou ◽  
Wei Jun Cao ◽  
Long Min Jiang ◽  
Hui Cao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Fire Resistance ◽  
Fire Protection ◽  
Structural Damage ◽  
Fire Retardant ◽  
Steel Structure ◽  
Steel Structures ◽  
Strength And Stiffness ◽  
Fire Conditions

As the result of great changes occurring to mechanical properties under high temperature (fire) conditions, steel structures will soon lose the strength and stiffness and lead to structural damage. Through analysis of the steel structure fire resistance design methods under the conditions of high temperature (fire), this article explores the most used fire protection methods in steel structures—brushing or painting fire-resistant coatings, studies the fire-resistance theory of steel structure under fire conditions; in addition, the author proposes the reasonable thickness of the steel structure fire retardant coating of fire-resistant design through design examples.

Fire Protection of Steel and Reinforced Concrete Structures of Industrial Buildings and Structures

2021 ◽  
pp. 50-56
Author(s):  
V.I. Golovanov ◽  
◽  
A.V. Pekhotikov ◽  
V.V. Pavlov ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Fire Protection ◽  
Temperature Regime ◽  
Fire Retardant ◽  
Steel Structures ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Industrial Buildings ◽  
Temperature Regimes

Variants of progressive solutions for the use of efficient fire protection means for steel and reinforced concrete structures of the industrial buildings and structures are considered for the purpose of increasing the actual fire resistance and ensuring the requirements of fire safety norms. Distinctive features of the temperature regimes in the initial phase of a real fire from a standard fire were established when assessing the fire resistance of building structures. It is proposed to use such standardized temperature regimes of fire for assessing the fire resistance of building structures, as standard — in the industrial buildings; temperature regime of hydrocarbons combustion — for oil and gas, petrochemical enterprises, offshore stationary platforms; tunnel temperature regime — in the road and railway tunnels. Considering the operating conditions and performance of work on fire protection, the degree of aggressiveness of the environment, the structural and methodological scheme was developed for selecting passive fire protection for steel structures. Recommendations are given on limiting the use of intumescent paints for load-bearing steel structures involved in the overall stability of buildings, with the required fire resistance limit of no more than 30 minutes. To calculate the temperature over the section of the structure during its heating, the dependences of the change in the coefficients of thermal conductivity and heat capacity of fire-retardant linings under fire were obtained. Experimental studies were conducted related to the fire resistance of reinforced concrete floor slabs and slabs with an external reinforcement system based on the carbon composite material with various types of fire-retardant materials. The issue of protecting the lining blocks of road and railway tunnels from brittle (explosive) destruction of concrete in a fire is considered. It is experimentally confirmed that the addition of polypropylene fibers to the concrete mixture replaces the use of fire protection for the tunnels enclosing structures.

Research of Fire Resistance of Elements of Steel Frames of Industrial Buildings

2021 ◽  
Vol 1038 ◽  
pp. 506-513
Author(s):  
Viktor Hvozd ◽  
Eugene Tishchenko ◽  
Andriy Berezovskyi ◽  
Stanislav Sidnei
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Mathematical Models ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Limit State ◽  
Steel Frames ◽  
Steel Structures ◽  
Computational Experiments ◽  
Industrial Buildings

The article considers and analyses the methods by which it is possible to carry out research to determine the fire resistance of elements of steel frames of industrial buildings. It is determined that it is expedient to use the means of computational fluid dynamics, which has no limitations due to the high cost, complexity, environmental friendliness and complexity in comparison with real experiments. In order to conduct the most reliable computational experiments, mathematical models of temperature and mechanical reaction to the thermal effect of fire were created, taking into account the equations of thermal conductivity, systems of differential equations of stress-strain state of solids in their numerical implementation based on the finite element method. The solution of mathematical models was carried out using computational fluid dynamics, which describes the process of heat and mass transfer in test fire furnaces during the determination of fire resistance of steel structures. According to the results of computational experiments it is shown that the limiting state of loss of bearing capacity of vertical and horizontal structures occurs due to the formation of a zone of plastic deformations taking into account the associative theory of plasticity. According to the results of computational experiments, the dependence of the limit of fire resistance on the level of applied load to structures, which is close to linear, was revealed. Based on the obtained dependences and the corresponding graphs, a technique is developed based on the use of maximum deformations of the elements with the corresponding fixation of the limit state on the loss of fire resistance in terms of bearing capacity by bending this curve.

Thin-Walled Cold-Formed Steel Beams with Holes in Lateral Flexural-Torsional Buckling

2013 ◽  
Vol 743 ◽  
pp. 170-175 ◽  
Author(s):  
Marcela Karmazínová ◽  
Jindrich Melcher ◽  
Martin Horáček
Keyword(s):  
Cross Section ◽  
Stability Problem ◽  
Design Procedure ◽  
Steel Structures ◽  
Torsional Stiffness ◽  
Steel Beams ◽  
Torsional Buckling ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Flexural Torsional Buckling

In this paper the study on lateral flexural-torsional buckling of steel sigma-cross-section beams with web holes will be presented. The analysis of corresponding stability problem is based on general approach derived for a group of beams including at least mono-symmetric sections loaded transversally to their plane of symmetry. The effective flexural and torsional stiffness of steel beams with holes has been verified by tests. The results of theoretical analysis were compared with specification design procedure and also with actual behaviour of set of beams investigated by experiments. The study conclusions aim to become the background of the supplements to specified provisions for the design of steel structures.

Fire Assessment of Steel Beam Members With Partial Passive Fire Protection Coverage

2012 ◽  
Author(s):  
Hunter Smith ◽  
Yavuz Ayhan ◽  
Ali Sari
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Fire Protection ◽  
Mechanical Response ◽  
Local Buckling ◽  
Offshore Structures ◽  
Heat Transfer Analysis ◽  
Passive Fire Protection ◽  
Non Linear ◽  
The Cross

In offshore structures there are instances where the application of passive fire protection (PFP) is not possible or desired on certain portions of a structural member’s surface area. The most common cases are those where the top surface is left unprotected due to the presence of deck grating or plating. Current code and standard provisions on heat transfer and strength assessment of restrained flexural members are not directly applicable to these cases. Thus, a case study is presented for performing a fire assessment of a restrained plate girder subjected to jet fire impingement with the top flange surface left unprotected. To assess residual strength and perform non-linear analyses under combined thermal and static loading, a heat transfer analysis was first performed to obtain the time histories of the two dimensional heat distributions throughout the studied cross-section. The results showed that the top flange heats up rapidly and the heat conducts very slowly down the web to the rest of the cross-section, with a very large thermal gradient occurring over the height of the section. Approximate screening calculations for the cross-section, based on AISC capacity equations, indicated that the member will quickly exceed its elastic capacity and that local buckling may occur prior to yielding. Advanced non-linear finite element analysis of the mechanical response confirmed large amounts of plasticity and local buckling occur, but showed that global integrity of the member is maintained for the duration of the fire due to redundancy and catenary action. Recommendations and conclusions on analysis methods for partially protected deck members are made based on the results of this study.

Ductile cement-based spray-applied fire-resistive materials

2016 ◽  
Vol 7 (2) ◽  
pp. 114-125 ◽  
Author(s):  
Qian Zhang ◽  
Victor C. Li
Keyword(s):  
Fire Protection ◽  
Experimental Studies ◽  
Steel Structures ◽  
Material Design ◽  
Field Application ◽  
High Rate ◽  
Cementitious Composite ◽  
Content Type ◽  
Engineered Cementitious Composite ◽  
Passive Fire Protection

Purpose Spray-applied fire-resistive materials (SFRMs) are the most commonly used passive fire protection for steel structure in the USA. However, they are often called into question because of their poor durability (cohesive and adhesive) performance. Being an inherently brittle material with low tensile strength, SFRM tends to dislodge and delaminate under extreme loads and service loads. Such loss of fire protection greatly endangers the steel structures, especially under multi-hazards like post-earthquake/impact fires. The purpose of this paper is to introduce a new technology of a ductile cement-based SFRM, namely, spray-applied fire-resistive engineered cementitious composite (SFR-ECC) that overcomes the aforementioned problems and contributes toward enhanced fire safety of steel structures. Design/methodology/approach SFR-ECC has been developed as a durable alternative to conventional SFRM by adopting engineered cementitious composite (ECC) technology in the material design process. Various experimental studies have also been conducted to fully evaluate the performance of SFR-ECC. Findings It is found that SFR-ECC possesses much better durability performance under both static and high-rate loading compared to conventional SFRMs. With many unique properties, applications of SFR-ECC for pre-fabrication of passive fire protection are also found to be feasible. Originality/value This paper is a comprehensive introduction of the newly developed SFR-ECC. It summarizes the key properties of SFR-ECC and provides a useful guideline for further investigation and field application of SFR-ECC.

Numerical Simulation of Fire Resistance Performance for Planar Frame with Concrete Filled Steel Tubular Columns and Steel Beams

2011 ◽  
Vol 94-96 ◽  
pp. 755-758
Author(s):  
Yan Yin ◽  
Tang Li
Keyword(s):  
Fire Resistance ◽  
Limit State ◽  
Plastic Hinge ◽  
Local Buckling ◽  
Horizontal Displacement ◽  
Steel Beams ◽  
Bottom Flange ◽  
Tubular Columns ◽  
Fire Endurance ◽  
Resistance Performance

In this paper, the fire resistance performance of the unprotected two-layer and two-cross planar frame, which is composed of concrete filled steel tubular columns and steel beams, was analyzed under local fire by ANSYS. After analyzing the structure with the method of hot - structural coupling using standard heating curve ISO-834, some consequence were obtained such as the regularity of temperature field distribution of beams and columns and the fire endurance and critical temperature of the structure. It turned out that the bottom flange at the end of the beams appeared local buckling when the structure reached the limit state by fire, and the first plastic hinge appeared at the end of beams. Furthermore, because the horizontal displacement of column is small, the overall collapse of structure can be avoided effectively.

Numerical Simulation Analysis of the Overall Stability of Hot-Rolled H Section Steel Beam Based on ANSYS

2014 ◽  
Vol 934 ◽  
pp. 230-232
Author(s):  
Peng Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Steel Structures ◽  
Steel Beams ◽  
Finite Element Software ◽  
Overall Stability ◽  
Uniformly Distributed Loads ◽  
Hot Rolled ◽  
Current Code ◽  
Shaped Section

Based on finite element software ANSYS, the paper analyzed the overall stability of hot-rolled H shaped section Q235 steel beams with two symmetric axis under uniformly distributed loads, compared with the current code for design of steel structures, discussed the effect of high span ratio on the results of numerical simulation. The results show that when the high span ratio is less than 30, numerical analysis method and the standard methods agree well, but when the high span ratio exceeds 30, the error is big.

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