| 1. |
- Mohaine, Siyimane, et al.
(författare)
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PERFORMANCE OF PASSIVE PROTECTION OF CROSS LAMINATED TIMBER DURING STANDARD FURNACE TESTS AND NATURAL FIRES
- 2023
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Ingår i: 13th World Conference on Timber Engineering, WCTE 2023. - 9781713873297 ; 3, s. 1839-1847
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Konferensbidrag (refereegranskat)abstract
- This paper presents the results of an experimental campaign designed to compare and understand the performance of passive protection under exposure to standard furnace tests and natural fires. As part of this campaign, five natural fire experiments were performed with partially protected cross-laminated timber (CLT) compartments under a range of ventilation conditions. In all the tests, only one side wall was left completely unprotected, and all other timber surfaces were protected with either two layers of 18 mm standard gypsum boards (GB) or two layers of 25 mm standard GBs. The structural CLT ceilings were subjected to a superimposed dead load of 1.35 kN/m² during the natural fire tests, and the fire load was (on average) 950 MJ/m²; chosen to represent the Eurocode 1991-1-2 characteristic value for dwellings. The performance of the passive protection was mainly evaluated with regards to the time to reach a protected timber surface temperature of 250°C. The testing confirms that the resulting fire protection performance of a given gypsum board layout depends on the ventilation conditions of the fire compartment, with more severe (and closest to ISO testing) outcomes when testing under ventilation-controlled scenarios. This paper provides data that sheds light on the co-dependency of the passive protection design and compartment fire dynamics and underlines the importance of considering the safety objectives of a building when defining the performance criteria of its structural elements.
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| 2. |
- Veljkovic, Milan, et al.
(författare)
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Structural member behaviour and analysis in case of fire
- 2008
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Ingår i: Urban Habitat Constructions under Catastrophic Events. - Valetta : Editura Universitatii de Vest din Timisoara / University of the West Timisoara Publishing House. - 9789990944402 ; , s. 45-50
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Charlier, Marion, et al.
(författare)
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TRAFIR: Characterization of TRAvelling FIRes in large compartments
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inspection of recent fire events in large compartments reveals them to have a great deal of non-uniformity, they generally burn locally and move across floor plates over a period of time. This phenomenon which generates transient heating of the structure is idealized as “travelling fire”.A first series of tests was launched to define a fire load representative of an office building according to Eurocodes. Additional tests where the fire dynamics were controlled were launched to develop an understanding of the fire exposure to steel structures.Then, a second series of large scale tests were performed in real building dimensions. These tests had no artificial control over the dynamics, which allowed a realistic characterization of the fire. The fire load was identical for all tests, only the openings were modified.CFD numerical models were developed to reproduce the experimental campaign and to launch parametrical analyses. This allowed to provide information concerning the conditions which may lead (or not) to a travelling fire scenario.An analytical model for the characterization of a travelling fire was developed and implemented in a simple calculation tool. It allows to evaluate the fire location, the gas temperatures in the flames, the heat fluxes in the different parts of the compartment and the temperature in a steel member. In addition, the methodology is introduced in the FEM software SAFIR and OpenSees.Ultimately, a design guide was prepared including worked examples which are detailed step-by-step and for which the influence of the inputs on the results is analysed.
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| 4. |
- Gernay, Thomas, et al.
(författare)
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Experimental investigation of structural failure during the cooling phase of a fire : Timber columns
- 2023
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 47:4, s. 445-
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes fire tests on loaded glued laminated timber columns in which the structural response was measured during the heating and cooling phases. Identical columns with 280 × 280 mm2 cross-section and 3.7 m length were tested under various heating durations in a standard furnace to investigate integrity to full burnout. Two of the columns were subjected to ISO 834 heating until failure and their measured fire resistance was 55 and 58 min, respectively. Two columns were subjected to 15 min of ISO 834 heating followed by controlled cooling; these columns failed during the cooling phase, respectively after 98 and 153 min. Flame self-extinction occurred after approximately 40 min while smoldering continued locally. Two columns tested under 10 min of ISO 834 heating both survived the defined heating–cooling exposure. Thermocouples inside the columns show sustained temperature increases for hours after the end of the heating phase. These full-scale furnace experiments show that timber columns may fail during the cooling phase after exposure to standard heating for about 25% of the standard fire resistance duration. These results, in line with previous numerical predictions, highlight the need for further investigation into fire safety until full burnout for timber structures.
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| 5. |
- Gernay, Thomas, et al.
(författare)
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Experimental investigation of structural failure during the cooling phase of a fire : Concrete columns
- 2022
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Ingår i: Fire safety journal. - : Elsevier Ltd. - 0379-7112 .- 1873-7226. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- Structures may collapse during the cooling phase of a fire, yet standard furnace tests only measure the response under heating. There lacks experimental test protocols and design methods to assess resistance until burnout. This paper describes a new experimental approach for burnout resistance evaluation, reports experimental data on loaded reinforced concrete columns in furnace tests with cooling down phases, and presents numerical models of the tests. The test results show that columns designed for a standard fire resistance of 60 min exhibited a fire resistance of 83 min in the furnace but failed during the cooling phase when the burners were shut off after 72 min while the load was maintained. Two other specimens survived exposure to heating of 45 and 55 min, respectively, and their residual capacity was measured. Finite element analyses show agreement with the tests, showing applicability of numerical methods for evaluating burnout resistance of concrete columns. These findings demonstrate experimentally that delayed thermal-mechanical effects can jeopardize structural stability in real fires, and provide a framework to measure these effects. Moving beyond fire resistance to quantify the response until burnout will support designs for safety of occupants and firefighters throughout the fire and promote repairability and resilience.
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| 6. |
- Nadjai, Ali, et al.
(författare)
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Travelling fire in full scale experimental building subjected to open ventilation conditions
- 2023
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Ingår i: Journal of Structural Fire Engineering. - : Emerald Group Holdings Ltd.. - 2040-2317 .- 2040-2325. ; 14:2, s. 149-166
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In the frame of the European RFCS TRAFIR project, three large compartment fire tests involving steel structure were conducted by Ulster University, aiming at understanding in which conditions a travelling fire develops, as well as how it behaves and impacts the surrounding structure. Design/methodology/approach: During the experimental programme, the path and geometry of the travelling fire was studied and temperatures, heat fluxes and spread rates were measured. Influence of the travelling fire on the structural elements was also monitored during the travelling fire tests. Findings: This paper provides details related to the influence of travelling fires on a central structural steel column. Originality/value: The experimental data are presented in terms of the gas temperatures recorded in the test compartment near the column, as well as the temperatures recorded in the steel column at different levels. Because of the large data, only fire test one results are discussed in this paper.
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| 7. |
- Robert, Fabienne, et al.
(författare)
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NATURAL FIRE TESTS ON GLT COLUMNS INCLUDING THE COOLING DOWN PHASE
- 2023
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Ingår i: 13th World Conference on Timber Engineering, WCTE 2023. - : World Conference on Timber Engineering (WCTE). - 9781713873297 ; 3, s. 1848-1854, s. 1848-1854
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Konferensbidrag (refereegranskat)abstract
- This paper presents the data and the results of seven fire tests performed on glue laminated timber columns in a compartment built especially for the tests and in which timber wood cribs created a so-called natural fire. These tests are part of a research programme titled "burnout resistance" to establish a new methodology to better describe performance of structural elements during the whole duration of a fire. Comparisons with similar tests made in a fire resistance furnace allow comparing charring rates observed in standard conditions and in natural fires.
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