European recommendations for the fire safety of steel structures: Calculation of the fire resistance of load bearing elements and structural assemblies exposed to the standard fire

1984 ◽  
Vol 7 (2) ◽  
pp. 204 ◽  
Author(s):  
D.R. Fairbairn
Fire ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Marina Gravit ◽  
Daria Shabunina

The requirements for the fire resistance of steel structures of oil and gas facilities for transportation and production of hydrocarbons are considered (structures of tankers and offshore platforms). It is found that the requirements for the values of fire resistance of structures under hydrocarbon rather than standard fire conditions are given only for offshore stationary platforms. Experimental studies on the loss of integrity (E) and thermal insulating capacity (I) of steel bulkheads and deck with mineral wool under standard and hydrocarbon fire regimes are presented. Simulation of structure heating was performed, which showed a good correlation with the experimental results (convective heat transfer coefficients for bulkheads of class H: 50 W/m2·K; for bulkheads of class A: 25 W/m2·K). The consumption of mineral slabs and endothermic mat for the H-0 bulkhead is predicted. It is calculated that under a standard fire regime, mineral wool with a density of 80–100 kg/m2 and a thickness of 40 to 85 mm should be used; under a hydrocarbon fire regime, mineral wool with a density above 100 kg/m2 and a thickness of 60–150 mm is required. It is shown that to protect the structures of decks and bulkheads in a hydrocarbon fire regime, it is necessary to use 30–40% more thermal insulation and apply the highest density of fire-retardant material compared to the standard fire regime. Parameters of thermal conductivity and heat capacity of the applied flame retardant in the temperature range from 0 to 1000 °C were clarified.


Author(s):  
Patrick Meyer ◽  
Peter Schaumann ◽  
Martin Mensinger ◽  
Suet Kwan Koh

In Germany, regulations for hollow spaces in slab systems require 30 minutes standard fire resistance of the load-bearing steel construction. Within a current national research project a natural fire scenario for the hollow space was developed based on realistic fire loads and ventilation conditions in the hollow space. Assuming this realistic fire scenario in the hollow space, two large scale tests on an innovative composite floor system were performed to evaluate the influence on the load bearing behaviour of the floor system. The integrated and sustainable composite floor system consists of a prestressed concrete slab, an unprotected, bisected hot rolled I-profile with composite dowels either in puzzle or clothoidal shape, and removable floor panels on the top of the I-profile. This floor system ensures the opportunity to adjust the technical building installations in accordance with the use of the building. This integrated and sustainable composite floor system was developed in several research projects. The standard fire resistance R90 for the fire scenario below the slab system has already been proven successfully. In this paper, experimental investigations regarding the heating and load bearing behaviour of the innovative composite floor system under the newly developed natural fire scenario of hollow spaces are presented. In doing so, the special test set-up to realise the fire tests for the fire scenario hollow space will be described in detail. After the fire scenario for the hollow space, the specimen was subjected to the ISO standard fire curve to establish the failure temperature of the unprotected I-profile. In addition to the temperature development and the load bearing behaviour inside the innovative floor during the heating phase, the cooling phase and the influence of a web opening on the load bearing behaviour will be discussed.


2020 ◽  
pp. 43-54
Author(s):  
Владимир Ильич Голованов ◽  
Андрей Владимирович Пехотиков ◽  
Владимир Валерьевич Павлов

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.


2017 ◽  
Vol 8 (3) ◽  
pp. 324-336 ◽  
Author(s):  
Kristian Hertz ◽  
Luisa Giuliani ◽  
Lars Schiøtt Sørensen

Purpose Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of load-bearing capacity of hollow-core slabs when exposed to fire. Design/methodology/approach Furthermore, it compares theoretical calculation and assessment according to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Findings Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. Originality value For the first time, the mechanisms responsible for loss of load-bearing capacity are identified, and test results and calculation approach are for the first time applied in accordance with each other for assessment of fire resistance of the structure.


Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 187
Author(s):  
Marina Gravit ◽  
Elena Golub ◽  
Boris Klementev ◽  
Ivan Dmitriev

In a situation where a fire occurs either in a tunnel with a burning vehicle carrying petroleum products, at an offshore platform, or at an oil and gas asset to be protected, such a case is commonly described using a hydrocarbon fire curve. Therefore, it is extremely important to design construction, which can maintain stability and bearing capacity both under the standard and hydrocarbon fire modes. The purpose in this work is to hold a behavior simulation of a steel structure with fireproofing ensured through lightweight concrete slabs reinforced with fiber glass as well as a validation of the outcomes by assessing the experimental findings obtained from the relevant fire tests. A fire resistance study was carried out here for steel structures with a profile ratio of 156 mm−1 for the cases of a standard fire and of a hydrocarbon fire. A constant static load of 687 kN (70 tf) was taken for standard fire and 294 kN (30 tf) for hydrocarbon fire; the column was under vertical compression with one end resting on a hinged support and the other end rigidly fixed. The specimen design incorporated single-layer box-section cladding made of Pyro-Safe Aestuver T slabs, 40 mm thick and of a 650 kg/m3 density, pre-cut to fit the column size. The column strength loss (R) ultimately occurred after 240 min in the standard fire case and after 180 min in the hydrocarbon fire case. As the breach in the fireproofing structural integrity (E) or the installation accuracy cannot be considered, the limit state indicators may show certain discrepancies. According to the simulation performed using SOFiSTiK software, the design fire resistance rating of the structure in a hydrocarbon fire case was 58% higher than the figure obtained by holding fire tests due to the slabs cracking during the experiment session; the discrepancy between the outcomes of the session and the simulation in a standard fire case was as much as 15%.


2020 ◽  
Vol 13 (2) ◽  
pp. 398-432
Author(s):  
D. L. ARAÚJO ◽  
G. D. C. PINTO

Abstract Prestressed hollow core slabs are one of the structural systems whose use has increased the most in recent years in Brazil due to its efficiency and versatility. They can be used in many types of structural systems, such as masonry, precast concrete, cast-in-place concrete and steel structures. However, there are few analytical models to evaluate the fire behavior of hollow core slabs. In a simplified way, the fire resistance is evaluated indirectly through the minimum distance of the surface in contact with fire to the reinforcement axis. In this paper, some numerical models in finite element software were developed to analyze the variation of temperature with fire exposure time of shallow hollow core slabs, focusing on the presence of voids in the transversal section of the slab. The 500 °C isotherm method applied to 20 cm high slabs confirmed the Standard Fire Resistance obtained from the tabular method. However, when applied to shallow prestressed hollow core slabs that are 16 cm high, the 500 °C isotherm method indicated that the Standard Fire Resistance of these slabs is lower than values obtained from tabular methods.


2020 ◽  
Vol 1 (2) ◽  
pp. 29-40
Author(s):  
S Novak ◽  
M Novak ◽  
O Bedratiuk

The results of the study aimed at further improvement and development of procedures for evaluating methods of determining the fire resistance characteristics of building structures are presented. The features of estimation of methods of determination of characteristics of fire resistance of building structures are determined. It is established that for the validation of experimental-calculation methods intended to determine the thickness of fire protection of building structures, which ensures their fire resistance in a wide range of parameters of these structures, it is impossible to use samples of structures with certain properties due to their inability to create. A procedure for such validation using a computational experiment method is proposed. In this procedure, accurate (conditional) temperature data for steel column specimens are determined by solving a direct one-dimensional non-stationary thermal conductivity problem. The validity of the proposed validation procedure by its application for the experimental calculation method, designed to determine the thickness of fire protection materials for load-bearing steel structures (columns and beams), has been established. It is established that the overwhelming number of calculated values of the thickness of the fire protection materials, determined by this method, exceeds its true values, which indicates the acceptability of the obtained results in terms of providing fire resistance of load-bearing steel structures. It is established that the difference between the calculated and actual values of the thickness of the fire protection materials can reach a considerable value (twice or more).The direction of further researches which are focused on revealing of influence of thermophysical properties of fire protection materials and stress-deformed state of samples of steel structures during the test on the accuracy of the method. This will identify more appropriate procedures for evaluating the method and processing the experimental data with increased accuracy.


2021 ◽  
Vol 11 (6) ◽  
pp. 2521
Author(s):  
Feng Jiang ◽  
Jianyong Liu ◽  
Wei Yuan ◽  
Jianbo Yan ◽  
Lin Wang ◽  
...  

Improving the fire resistance of the key cables connected to firefighting and safety equipment is of great importance. Based on the engineering practice of an oil storage company, this study proposes a modification scheme that entails spraying fire-retardant coatings on the outer surface of a cable tray to delay the failure times of the cables in the tray. To verify the effect, 12 specimens were processed using five kinds of fire-retardant coatings and two kinds of fire-resistant cotton to coat the cable tray. The specimens were installed in the vertical fire resistance test furnace. For the ISO 834 standard fire condition, a fire resistance test was carried out on the specimens. The data for the surface temperature and the insulation resistance of the cables in trays were collected, and the fireproof effect was analyzed. The results showed that compared with the control group, the failure time of the cable could be delayed by 1.57–14.86 times, and the thicker the fire-retardant coatings were, the better the fireproof effect was. In general, the fire protection effect of the fire-retardant coating was better than that of the fire-resistant cotton.


2012 ◽  
Vol 628 ◽  
pp. 156-160
Author(s):  
In Kyu Kwon ◽  
Hyung Jun Kim ◽  
Heung Youl Kim ◽  
Bum Yean Cho ◽  
Kyung Suk Cho

Structural steel has been used since the early 1970’s in Korea as primary structural members such as columns, beams, and trusses. The materials have much higher strength such as fast construction, high load bearing capacity, high construction quality but those have a fatal weakness as well. Load-bearing capacity is going down when the structural members are contained in fire condition. Therefore, to protect the structural members made of steels from the heat energy the fire resistance performance required. Generally, the fire resistance performance have evaluated from the exact fire tests in fire furnaces. But the evaluation method takes much more time and higher expenses so, the engineering method requires. The engineering method not only adopts a science but also an engineering experience. In this paper, to make various data-bases for evaluation of structural members such as columns(H-section, RHS), beams, loaded fire tests were conducted and derived not only each limiting temperature but also fire resistance respectively.


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