The concept of calculating the actual limit of fire resistance of building structures

2021 ◽  
pp. 12-17
Author(s):  
Юрий Николаевич Шебеко ◽  
Алексей Юрьевич Шебеко

Проведен краткий анализ понятий, связанных с расчетом пределов огнестойкости строительных конструкций. Дано определение термина «фактический предел огнестойкости», которое отсутствует в нормативных документах по пожарной безопасности. Отмечено, что это связано с использованием на практике значений пределов огнестойкости, определенных для стандартных температурных режимов пожара, в то время как на практике указанные температурные режимы, как правило, отличаются от стандартных. Предложена концепция определения фактического предела огнестойкости, основанная на моделировании воздействия на строительную конструкцию температурного режима реального пожара (например, с помощью программного комплекса FDS 6). The brief analysis of definitions connected with estimation of fire resistance limits of building structures is conducted. There is given the determination of term “actual fire resistance limit” that is absent in fire safety normative documents. It is caused by practical application of the fire resistance limits determined for standard temperature regimes of fires only, but at the same time the temperature regimes of real fires as a rule differ from the standard regimes. There is proposed the method for determination of the actual fire resistance limit based on the modeling of influence of the real fire temperature regime on buildings structures. This modeling can be made by an application of CFD methods (for example, with the help of FDS 6 software complex). The required reliability of the building structure is considered. The proposed method can solve the problem of practical applicability of certain structural unit during designing buildings and structures, for which the use of the resistance limits obtained for the standard fire temperature regimes can lead to unjustified economic expenditures without an appropriate elevation of fire safety level of the object.

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.


2019 ◽  
Vol 123 ◽  
pp. 01022 ◽  
Author(s):  
Andrіі Kovalov ◽  
Volodymyr Konoval ◽  
Anastasiia Khmyrova ◽  
Kateryna Dudko

The statistical data of the fire and technogenic safety in Ukrainian mines have been studied. A literary analysis has been made of advanced expertise in determining the fire resistance of building structures. It has been studied the thermal state and fire resistance of hollow-core floors using the fire tests and the calculated determination of the fire resistance degree of a structure based on a two-dimensional model of thermal conductivity and convective heat transfer implemented in the ANSYS R17.1 software complex. The fire test of hollow-core floor has been analysed and the use of a computational-experimental method is proposed to determine the parameters when simulating the thermal state and the fire resistance of both protected and unprotected hollow-core floors. A technique has been developed for simulating the thermal state and the fire resistance of hollow-core floors, which can be used in assessment of the fire resistance degree of reinforced concrete building structures both in industrial construction and in the mining industry.


Author(s):  
R. M. Djumagaliev ◽  
◽  
O. K. Kokushev ◽  
T. R. Djumagaliev ◽  
R. A. Beisengazinov ◽  
...  

On the base of analyses on the development of the construction industry as well as fires occurring in Kazakhstan, the article justifies the areas of fire prevention related to technical regulation that is the certification of materials, construction structures and engineering systems. The translucent building structures have increasing application in modern construction techniques. For such structures, the most vulnerable indicator is the fire resistance limit. A technical solution is offered to increase this indicator by using water irrigation. On the base of existing international and national regulatory documents, a number of methods has been developed for experimental determination of the actual fire resistance limit by cooling of structures with water in case of fire. Large-scaled fire researches have been carried out to determine the actual limit of fire resistance of the translucent partition made of tempered glass "Float" with the thickness of 12 mm, M1 grade both in the presence of water irrigation and in the absence thereof. The tests were carried out under standard and actual fire conditions. Optimal parameters of water irrigation are determined. On the base of research results, it is proposed to improve the construction standards in this field as well as methodological documents in the field of certification tests.


Fire Safety ◽  
2019 ◽  
pp. 78-83
Author(s):  
Yu. I. Rudyk ◽  
V. M. Shunkin

Introduction. In order to protect objects from dangerous manifestations of fire of cable products, electrical lines are designed and projected in accordance with the fire-protection requirements and the normative documents. Purpose. The purpose of this article is to analyze this problem in several areas concerning the situation with a systematic approach to the technical regulation in Ukraine of such a sector of fire safety as the requirements for cable-wiring lines. Methods. Methods of research: calculations using a mathematical model; comparison of the results of the calculation, forecasting of the boundary parameters of the technical condition and monitoring of the cable material properties; examination, qualification, definition of indicators of fire safety of cables and wires in the composition of the electrical grids of buildings, structures, foundations and metal structures, taking into account laying conditions. Different methods for volume and mass calculating, fire tests of electrical and fiber optic cables were applicated. Tests of vertically arranged wires or cables laid in beams on the vertical propagation of the flame (Category A F / R, Category A, Category B) were conducted. Results. The experimental study of the installation parameters test and indicators of fire safety for cable-wiring products in their vertical laying that reduce the overall fire safety level of facility electric power operation were conducted. Critical analysis of the current state of development was done. The basis of the fire safety requirements for standardization of cable lines were formulated. The measures for testing methods implementation with description of these methods were proposed. Conclusion. Determination of the combustible material quantity by volume and by mass is not regulated in the current normative documents on fire safety, although this criterion is often used precisely when establishing requirements for fire safety: to buildings, cable installations, to the installation of fire automatics systems and to others. A method for calculating the volume of combustible material for determining the fire risk of cable-conductive products is proposed. The method can be used during designing of wiring lines and during their exploitation. Experimental researches of fire hazard indicators of cable-wiring products were conducted; their group of flame distribution was installed. The method of determining the quantity of combustible material by volume, by mass and with testing of mass loss of combustible material was applied.


2018 ◽  
Vol 193 ◽  
pp. 03026 ◽  
Author(s):  
Marina Gravit ◽  
Vladimir Lyulikov ◽  
Alina Fatkullina

The review of modern software systems that allow producing modeling and calculation of fire resistance of building structures, as well as simulating fire protection, is given. Particular attention is paid to the software Sofistik, which allows you to synchronize with Autodesk Revit and calculate the fire protection of building structures for various temperature regimes.


2020 ◽  
Vol 11 (3) ◽  
pp. 311-324
Author(s):  
Eva Lubloy

Purpose The aim of the research was to investigate the effect of concrete strength on the fire resistance of structures. At first, it may seem contradictory that higher concrete strengths can decrease the fire resistance of building structures. However, if the strength of the concrete exceeds a maximum value, the risk of spalling (the detachment of the concrete surface) significantly. Design/methodology/approach Prefabricated structural elements are often produced with higher strength. The higher concrete strengths generally do not cause a reduction in the load bearing capacity, but it can have serious consequences in case of structural fire design. Results of two prefabricated elements, namely, one slab (TT shaped panel) and one single layer wall panel, were examined. Results of the specimen with the originally designed composition and a specimen with modified concrete composition were examined, were polymer fibres were added to prevent spalling. Findings As a result of the experiments, more strict regulations in the standards the author is suggested including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is required after polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons. Originality/value As a result of the experiments, the author suggests including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is necessary to require the addition of polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons.


Author(s):  
V.I. Golovanov ◽  
◽  
A.V. Pekhotikov ◽  
V.V. Pavlov ◽  
◽  
...  

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.


2021 ◽  
Vol 30 (5) ◽  
pp. 5-22
Author(s):  
B. A. Klementev ◽  
A. V. Kalach ◽  
M. V. Gravit

Introduction. Currently, national standards and codes of practice contain deterministic values of the fire resistance of building structures of facilities of the Russian fuel and energy complex (FEC), while a probabilistic approach to determining their fire resistance is not specified in the Russian regulatory documents. The methodology of the probabilistic approach to the fire resistance of structures is detailed in API 2218 “Fireproofing Practices in Petroleum and Petrochemical Processing Plants”, developed by the American Petroleum Institute.Methods. A comparative analysis of the Russian regulatory documents on fire safety and API 2218 in terms of the established concepts of fireproofing and requirements for the fire resistance limits of building structures of oil and gas industry facilities, is carried out.Results. It was established that the Russian Federation has no regulatory documents establishing methods based on the probabilistic approach, including determination of the required fire resistance limits and points of application of fire-resistant coatings at facilities of the fuel and energy complex by analogy with international standard API 2218.Conclusion. Based on the analysis, it was concluded that approaches to the philosophy of the fire resistance of structures of buildings and structures of the fuel and energy complex in the documents under consideration are fundamentally different. In order to improve the Russian regulatory and technical framework, governing fire safety and fire resistance, it is proposed to consider the requirements of foreign documents that take into account proven international engineering and technical practices, in particular, the use of a probabilistic approach taking into account hydrocarbon fires.


2018 ◽  
Vol 788 ◽  
pp. 36-44
Author(s):  
Liudmyla Demydchuk ◽  
Dmytro Sapozhnyk

The normative documents of Ukraine (DBN V.1.1.7 ̶ 2016) [1] establish that the limit of fire resistance of reinforced-concrete building structures is determined by the calculation method or by fire tests, and shall be at least 45 minutes. Taking into account the modern construction technologies, namely, the reduction of the section of the main building reinforced-concrete structures, it is expedient to use fire-retardant coatings to provide the necessary fire resistance limit.


Sign in / Sign up

Export Citation Format

Share Document