Determination of the Charring Rate of Timber to Estimate the Fire Resistance of Structures at Real Temperature Modes of Fires

Author(s):  
Taras Shnal ◽  
Serhii Pozdieiev ◽  
Stanislav Sidnei ◽  
Andrii Shvydenko
Author(s):  
Petr Kuklík ◽  
Magdaléna Charvátová

The paper is focused on the influence of fire resistant coatings used on OSB boards on the fire resistance of entire light timber frame wall assemblies. Two fire tests were performed in the fire test laboratory of PAVUS, a.s. in Veselí nad Lužnicí. The fire tests were performed on a load bearing wall. The wall dimensions were 3.0 (depth) x 3.0 (height) m. According to EN 1995-1-2, the calculation for fire paints and coatings is not possible. The aim of the paper is the determination of the influence of this type of coating on the OSB board’s charring rate, the determination of the start of charring of a timber stud and the fire resistance of the whole construction.


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.


Author(s):  
Yury Shebeko ◽  
Aleksey Shebeko ◽  
Andrey Zuban

Проанализирована взаимосвязь разброса значений пределов огнестойкости стальных конструкций со вспучивающимися огнезащитными покрытиями и соответствующего этому разбросу интервала толщины огнезащитного покрытия. Предложена методика, на основании которой может быть осуществлен выбор необходимой толщины огнезащитного покрытия в зависимости от заданных значений дисперсии предела огнестойкости и приведенной толщины конструкции при заданной доверительной вероятности.An analysis of a relationship between fire resistance limits scatter for steel structures coated with intumescent fire retardant coating and an appropriate interval of thicknesses of the coating was carried out. A methodology for the determination of this relationship was proposed. This methodology was tested on a practical example. A steel structure with a reduced thickness of 6 mm was considered. A typical dependence of the required thickness of the structure was taken into account. A ratio of a mean square deviation of the fire resistance limit to this limit was accepted to be equal 0.1. Using these values an appropriated interval of the thicknesses of the intumescent fire retardant coating was determined. This interval can be calculated for any given confidence level. Boundaries of this interval can be not symmetric in relation to the value of the normative thickness of the fire retardant coating. The proposed methodology can be used for the determination of the required thicknesses of the intumescent fire retardant coatings on steel structures for the given r value, reduced thickness of the structure and the confidence level.


1998 ◽  
Vol 4 (2) ◽  
pp. 113-124
Author(s):  
H.-P. Leimer

Abstract As there are no certificated qualification for the fire resistance period of halftimbered walls different walls with and without claddings were tested. The tests were carried out in a small fire chamber and are based on DIN 4102. On the basis of the tests the dependence of the building elements and materials according tofire were revealed. It was obvious that careful sealings mainly in the area of joints could reduce the passage of fire and thereby the failure of the whole construction. Good sealings are clay and other insulating mortars that are used for infillings. Good sealing materials are further plaster and/or insulating plaster layers just as panel kind materials like gypsum and fire prevention boards. The present results are not able to replace a test according to DIN 4102 Τ 2/3 but they can be helpful for a judgement of an individual expert's opinion.


Author(s):  
Paweł Roszkowski ◽  
Paweł Sulik

<p>Sandwich panel is the material that is easy and quickly to install. Basing on a great experience in the area of determination of the fire resistance class of construction building elements the authors describe the properties and behavior of building elements made of the sandwich panels exposed to fire. The article presents the results of fire resistance tests carried out in accordance with EN 1364-1 non-bearing walls made of sandwich panels with use of different cores.</p>The following parameters were analyzed: temperature rise on unexposed side (I – thermal insulation), integrity (E) depending on the orientations and on the width of the sandwich panels, deflection depending on the thickness of the boards. Conclusions were made on the base of the analysis from fire resistance tests.


Author(s):  
Philipp Epple ◽  
Manuel Fritsche ◽  
Felix Reinker ◽  
Stefan aus der Wiesche

Abstract For fans without cooling it is possible to determine the hydraulic efficiency measuring the pressure and the temperature rise through the fan. The shaft work can be determined according applying the first law of thermodynamics for an open system. Without any losses the change of state would be isotropic and the work done equal to the specific heat at constant pressure of the fluid times the isentropic temperature rise in the impeller. Due to the losses, however, the real temperature at the exit of the impeller will be higher than the isentropic temperature since the real process is polytropic. The isentropic temperature at the exit of the impeller can be computed by the isentropic relations with the inlet temperature and the pressure rise. The hydraulic efficiency can be computed as the ratio of the isentropic temperature rise divided by the real temperature rise. In order to verify this thermodynamic approach for the determination of the hydraulic efficiency CFD simulations of a radial fan were performed. In the CFD simulation the hydraulic power, the shaft power, the pressure rise and the temperature rise can be read out and computed directly. In such a way the hydraulic efficiency computed by the ratio of the hydraulic power by the shaft power can be compared by the thermodynamically computed efficiency. In this work this comparison has been performed and the results and the precision of the thermodynamically predicted efficiency are presented and discussed in detail.


2013 ◽  
Vol 351-352 ◽  
pp. 42-45
Author(s):  
Yao Yao

Up till now, the design code for the determination of fire resistance of reinforced concrete (RC) columns is essentially based on tabulated data. Clearly, a more scientific approach based on an understanding of the fundamental behavior of columns in fire is timely andwill be useful to structural engineers. This paper develops a straightforward and rational method to predict the fire resistance of RC columns,which is based on the traditional Rankine approach. The effect of shear bond, if included in the Rankine approach, will yield moreaccurate predictions. Material deterioration at elevated temperature with regard to the strength and stability of columns is also quantified.


Author(s):  
Marcus Achenbach ◽  
Guido Morgenthal

The Advanced Calculation Method given in EN 1992-1-2 is accepted by engineers and building authorities for the determination of the fire resistance of reinforced concrete structures. It has been developed originally for the recalculation of laboratory tests: the time of failure is calculated for a given layout of reinforcement. But in the structural analysis of concrete columns, the area of reinforcement has to be calculated for a desired fire resistance. Design methods and strategies, which are suitable for the design of concrete compression members, require constant material properties and strain limits, which are not given for the Advanced Calculation Method. Therefore Achenbach and Morgenthal have proposed an extension of the Zone Method by Hertz, suitable for the implementation in commercial design software. In this paper, this Extended Zone Method is used to recalculate laboratory tests to determine the accuracy of this method. A statistical analysis of the results is performed to evaluate the statistical key data of the Extended Zone Method.


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