| 1. |
- Amon, Francine, et al.
(författare)
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Fire Impact Tool- Measuring the impact of fire suppression operations on the environment
- 2021
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Ingår i: Fire safety journal. - : Elsevier Ltd. - 0379-7112 .- 1873-7226. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden the responsibility for environmental damage when emergency responders are called to an incident is increasingly focussing on the responders. The problem is that most incident response personnel do not have the training and expertise to assess the environmental consequences of their suppression operations. The Fire Impact Tool was developed for training responders about how fire effluents and suppression media affect air, surface/groundwater and soil. The tool has three interdependent parts: fire models (for vehicles and enclosures), an environmental risk assessment (ERA) model for local impacts, and a life cycle assessment (LCA) model for global impacts. Users can create two scenarios that are compared with a reference case in which responders arrive at the incident and prevent the fire from spreading beyond the vehicle or enclosure but do not suppress the fire. The Fire Impact Tool is not intended for use during an actual fire incident. This work does not answer every question for every possible fire scenario, but it does provide a framework for deeper, broader, more comprehensive training and pre-planning. This is a necessary step toward a future in which responders are prepared to make informed decisions about firefighting strategies and tactics that include environmental consequences.
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| 2. |
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| 3. |
- Broström (red), Tor, et al.
(författare)
-
Brandsäkerhet för byggnader med kulturvärden: En kunskapsöversikt
- 2021
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Abstract [sv] Arbetet med brandsäkerhet för byggnader med kulturvärden kräver anpassade lösningar som också kan tillgodose ett bevarande av byggnaderna och deras kulturvärden. Det finns, utspritt, mycket kunskap och erfarenhet inom det här området både i Sverige och internationellt. För att tillgodose ett behov av samlad kunskap inom detta område initierade Brandforsk en kunskapsöversikt tillsammans med Akademiska hus, Fortifikationsverket, Kammarkollegiet, Kyrkans försäkring, Riksantikvarieämbetet och Statens fastighetsverk. Den här kunskapsöversikten syftar till att sammanställa och presentera den kunskap som finns. Ett kompletterande syfte är att definiera områden där kunskap saknas. Kunskapsöversikten är indelad i sex områden: 2. Skydd mot brands uppkomst 3. Spridning av brand inom byggnad 4. Spridning av brand till byggnad 5. Brandens påverkan på byggnadens stomme 6. Utrymning 7. Räddningstjänstens insats Med utgångspunkt från workshops har en sammanställning av behovsbilden gjorts. Kunskapsöversikten och behovsbilden ligger till grund för en gap-analys vilken pekar på behov av fortsatt forskning och utveckling. Abstract [en] Working with fire safety in historic buildings requires adapted solutions that can also satisfy the preservation of the buildings and their cultural values. There is a lot of knowledge and experience in this area both in Sweden and internationally. In order to make this available to end users, Brandforsk initiated a literature review together with a group of national sponsors. This literature review aims to compile and present the documented knowledge in the field. A complementary purpose is to define knowledge gaps. The review is divided into six areas: 2. Fire prevention 3. Fire spread within buildings 4. Fire spread between structures 5. Structural fire resistance 6. Evacuation 7. Fire and rescue service activities Based on workshops the needs of end users have been compiled. A comparison of the outcome of the review and the end user needs defines a knowledge gap pointing to the need for continued research and development.
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| 4. |
- Gehandler, Jonatan, 1982-, et al.
(författare)
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Interaktiv Miljöbedömning vid Insats: IMI-verktyget
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Programmet ”IMI-verktyget” (se länk till höger) är utvecklat för att ge räddningstjänst, studenter och forskare ett verktyg för att öka kunskapen angående konsekvenserna av taktiska val vid respons till en brand, exemplifierad av några fordons- och rumsbränder.I rapporten till höger (”fulltext”) beskriver hur verktyget fungerar och innehåller också exempel på datorlabbar som skulle kunna genomföras inom en brandingenjörsutbildning eller räddningsledarutbildning.
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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 : 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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| 6. |
- 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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| 7. |
- Mcnamee, Robert, et al.
(författare)
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Environmental Benefits of Rapid Fire Detection
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A study has been undertaken to investigate the environmental implication of early detection of a fire for the environmental impact of the fire when taking into account the global impact of the intervention itself and the need to replace building and contents as a function of the size and duration of the fire. The various scenarios investigated show that the greatest benefit is gained if a fire is detected early and can be extinguished while small without the intervention of the fire service. Significant savings can also be made if a sprinkler can keep the fire small while the fire service is on their way to the fire so that they meet a small fire which they can rapidly extinguish once they are on the scene. The methodology is based on an assumption of a single enclosure size, a generic fire load, detection and response. Future work should investigate different building typologies, fire loads and response types.
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| 8. |
- Mohaine, Siyimane, et al.
(författare)
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Cross-comparison of screening tests for fire spalling of concrete
- 2021
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 45:7, s. 929-
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Tidskriftsartikel (refereegranskat)abstract
- Concrete spalling is an important phenomenon to consider when evaluating the fire behavior of concrete, as this can sometimes have an impact on the structural capacity of the studied element. Spalling can be assessed experimentally using screening tests although it is influenced by the size, geometry, and boundary conditions of the tested element, among other factors. No standardized and systematic methods are yet available to assess concrete spalling sensitivity by testing. Plus, comparative results between screenings tests (small and medium scale) and full-scale tests to evaluate their representativity remain scarce in the literature. In this study, five different spalling tests—with different geometries and boundary conditions—that are used as screening tests were investigated. A concrete mix known to be sensitive to spalling was used to evaluate the representativity of two types of screening tests (material screening tests and intermediate-scale screening tests). The representativity of these test setups was evaluated by comparing the measured spalling depths to the spalling measured on a full-scale slab test using the same concrete mix. This comparative study confirmed that the presence of load and/or restraint was essential for a good representativity for a screening test but should always be implemented in large enough specimens.
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| 9. |
- 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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| 10. |
- Pimienta, Pierre, et al.
(författare)
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Recommendation of RILEM TC 256-SPF on fire spalling assessment during standardised fire resistance tests : complementary guidance and requirements
- 2024
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Ingår i: Materials and Structures/Materiaux et Constructions. - : Springer Science and Business Media B.V.. - 1359-5997 .- 1871-6873. ; 57:1
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Tidskriftsartikel (refereegranskat)abstract
- The recommendation is based on the co-authors’ work organized by the RILEM TC 256-SPF “Spalling of concrete due to fire: testing and modelling”. It aims to provide useful information, guidance and best practices in fire spalling assessment to laboratories that perform large-scale tests based on fire resistance test standards. It provides guidance on the spalling observation techniques during testing, as well as post-test spalling quantification/assessment methods. This document is intended to be used in conjunction with the fire resistance test standards, e.g. EN 1363-1 and ISO 834-1.
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| 11. |
- Pimienta, Pierre, et al.
(författare)
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Recommendation of RILEM TC 256-SPF on the method of testing concrete spalling due to fire : material screening test
- 2023
-
Ingår i: Materials and Structures/Materiaux et Constructions. - : Springer Science and Business Media B.V.. - 1359-5997 .- 1871-6873. ; 56:9
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Tidskriftsartikel (refereegranskat)abstract
- The recommendation is based on the co-authors’ work organized by the RILEM TC 256-SPF “Spalling of concrete due to fire: testing and modelling”. The Committee has defined two types of screening tests for characterization of concrete propensity to fire spalling: Material screening tests and Product screening tests. Definitions of both types of tests are given in the paper. The following recommendations apply to Material screening tests. The material screening tests described in these recommendations are a set of minimum requirements to test concrete spalling propensity (for example, the minimal specimen size). This document covers the aspects of concrete characterization, specimen geometries, storage conditions, test methods and measured parameters.
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| 12. |
- (red.) Broström, Tor, 1955-, et al.
(författare)
-
Brandsäkerhet för byggnader med kulturvärden : En kunskapsöversikt
- 2021
-
Bok (refereegranskat)abstract
- Arbetet med brandsäkerhet för byggnader med kulturvärden kräver anpassade lösningar som också kan tillgodose ett bevarande av byggnaderna och deras kulturvärden. Det finns, utspritt, mycket kunskap och erfarenhet inom det här området både i Sverige och internationellt. För att tillgodose ett behov av samlad kunskap inom detta område initierade Brandforsk en kunskapsöversikt tillsammans med Akademiska hus, Fortifikationsverket, Kammarkollegiet, Kyrkans försäkring, Riksantikvarieämbetet och Statens fastighetsverk. Den här kunskapsöversikten syftar till att sammanställa och presentera den kunskap som finns. Ett kompletterande syfte är att definiera områden där kunskap saknas. Kunskapsöversikten är indelad i sex områden:2. Skydd mot brands uppkomst3. Spridning av brand inom byggnad4. Spridning av brand till byggnad5. Brandens påverkan på byggnadens stomme6. Utrymning7. Räddningstjänstens insatsMed utgångspunkt från workshops har en sammanställning av behovsbilden gjorts. Kunskapsöversikten och behovsbilden ligger till grund för en gap-analys vilken pekar på behov av fortsatt forskning och utveckling.
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| 13. |
- 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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| 14. |
- Silfwerbrand, Johan, et al.
(författare)
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Stor steg för brandsäkerheten
- 2011
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Ingår i: Betong. - : Svenska betongföreningen. - 1101-9190. ; :1, s. 37-39
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 15. |
- Anderson, Johan, et al.
(författare)
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Experimental comparisons in façade fire testing considering SP Fire 105 and the BS 8414‐1
- 2018
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Ingår i: Fire and Materials. - : Wiley. - 0308-0501 .- 1099-1018. ; 42:5
-
Tidskriftsartikel (refereegranskat)abstract
- A comparison between full‐scale façade fire tests where SP Fire 105 and BS 8414‐1 were used regarding repeatability and the use of modeling to discern changes in the setups is presented. Two test series according to BS 8414‐1 were repeated outside using the same façade systems on 2 different days, whereas for the SP Fire 105 a set of common façade systems in Sweden were tested indoors. In particular, the results show that the wind around the test setup may have a significant impact on the tests and that the heat exposure to the façade surface will depend on the thickness of the test specimen where an increased temperature in front of the façade, and a decreased temperature on the façade 2.1 m above the fire room, is observed experimentally. The heat exposure to the test specimen varies to a more limited extent when an uncontrollable free burning fire source is used (in this study heptane and wood, respectively) and that this variation increases when wind is present.
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| 16. |
- Anderson, Johan, 1973-, et al.
(författare)
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Fire Safety of Façades
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Façade fires do not occur often (in comparison to other major structure fires) but in recent years there have been a number of spectacular façade fires in high rise building such as the recent fire in Grenfell Tower, London.Under-ventilated compartment fires may cause flames to spill out of window openings impinging the façade, thus devastating façade fires may start on one floor leap-frogging to adjacent floors. It is therefore necessary to limit or delay fire spread to higher floors. Requirements built on large scale fire testing may decrease the risk of these types of fires provided that the building is constructed according to the specifications provided by the manufacturer. Different countries have different regulations and tests for façades. New materials and façade systems are continuously introduced which might call for an update of these tests and regulations.This report summarizes experimental and modelling efforts in characterizing the fire safety of façades using the Swedish SP Fire 105 and the British BS 8414 methods. Recent experimental results and modelling is presented exploring the variations in the fire exposure, fire load and the fuel used. The fire source and the heat exposure to the façade are characterized by additional temperatures measured by plate thermometers while some other aspects are only treated in the numerical study such as a change in fuel. It is found that the results from the BS 8414 are largely affected by wind and climate since the experimental test was performed outdoors, moreover fire spread on wooden façades is also briefly discussed.In order to obtain a deeper understanding of the test methods and the results CFD (Computational Fluid Dynamics) Modelling in FDS was used. The models were based on measured input parameters including uncertainties and an assessment of the impact of said uncertainties. The models could often reproduce the experimentally found temperatures qualitatively and quantitatively. A detailed discussion on the regulations and the tests that lead to the SP Fire 105 test method is also presented. Summaries of the façade testing methods and conditions in other European countries are presented in the appendices.Finally possible ways forward in updating the façade testing and regulations are discussed.
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| 17. |
- Anderson, Johan, et al.
(författare)
-
Investigating machine learning for fire sciences : literature review and examples
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this work, a review of current literature on artificial intelligence (AI) and more specifically machine learning (ML) is presented. ML is illustrated by two case studies where artificial neural networks are used for regression analysis of 110 spalling experiments and 81 Fire Dynamics Simulator (FDS) models of tunnel fires. Tunnel fires are often assessed by fire safety engineers using time-consuming simulation tools where a trained model has the potential to significantly reduce time and cost of these assessments.A regression model based on a neural net is used to study small scale spalling experiments and similar accuracy compared to least-square fits are obtained. The result is a function based on 14 determining experimental parameters of spalling and result in, spalling times and depths. It is a relatively small effort to get started and set up models, comparably to regular curve fitting. In this first case study the training times are short, it is thus possible to establish how the model performs on average.The 81 tunnel fire simulations are trained using a similar neural net however it takes considerable time to organize data, creating input, target data of the desired format and training. Here, it is also crucial to normalize the data in order to have it in a suitable format when training. It should be noted that ML is often an iterative process in such a way that it may be difficult to know what settings will work before starting the process. It is equally important to illustrate and get to know the data, e.g., if there are large differences or orders of magnitude differences in the data. A normalization procedure is most often practical and will give better predictions.
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| 18. |
- Anderson, Johan, et al.
(författare)
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Modelling of fire exposure in facade fire testing
- 2017
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Ingår i: Fire and Materials. - : John Wiley & Sons. - 0308-0501 .- 1099-1018. ; 42:5, s. 475-483
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a comparative simulation study on 3 large‐scale facade testing methods, namely,the SP Fire 105, BS 8414‐1, and the ISO 13785‐2 methods, is presented. Generally goodcorrespondence between simulations and experimental data has been found, provided thatthermal properties of the facade material and heat release rates are known; however, thecorrespondence deviates in close proximity of the fire source. Furthermore, a statistical ensemblefor evaluating the effects stemming from uncertainty in input data is used. Here, it wasfound using this statistical ensemble that the variability was smaller in the ISO 13785‐2compared to the BS 8414‐1 method. The heat release rates (HRR) used in the simulations wereadopted from measurements except for the ISO method where the information in the standardwas used to approximate the HRR. A quantitative similarity between the HRR in the ISOmethod and the British method was found.
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| 19. |
- Anderson, Johan, et al.
(författare)
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Uncertainties in façade fire tests - Measurements and modeling
- 2016
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Ingår i: MATEC Web of Conferences. - : EDP Sciences.
-
Konferensbidrag (refereegranskat)abstract
- In this paper a comparison between test and modelling results are performed for two large-scale façade fire testing methods, namely SP Fire 105 and BS 8414-1. In order to be able to compare tests and modelling the uncertainties have to be quantified both in the test and the modelling. Here we present a methodology based on deterministic sampling to quantify uncertainties in the modelling input. We find, in general good agreement between the models and the test results. Moreover, temperatures estimated by plate thermometers is indicated to be less sensitive to small variations in model input and is thus suitable for these kind of comparisons.
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| 20. |
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| 21. |
- Boström, Lars, et al.
(författare)
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Fire test of ventilated and unventilated wooden façades
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Three large scale façade tests in accordance with SP Fire 105 as well as an ad hoc SBItest have been carried out. The façade tests included an inert façade made of lightweightconcrete, one façade with a plywood cladding and finally a façade with plywood claddingwith a fully ventilated cavity behind the cladding. The SBI test was made with plywoodwithout ventilation cavity. The aim of the tests was to perform well controlled tests withnumerous of measurements including heat release rate, heat from the combustionchamber, temperature on the façade surface, heat flux, plume temperatures andtemperatures in the ventilation cavity. The results from the tests will be used forvalidation of simulation techniques as well as input for further development of the façadetest methodology.Conclusions from the study were that the surface temperature for charring of the plywoodcladding in this configuration was in the region of 300 °C and that the energy releaseoriginated from the façade during the test was almost twice as high when there was a20 mm wide cavity behind the plywood cladding.Key words: fire test, facade, wood, ventilation cavity
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| 22. |
- Boström, Lars, et al.
(författare)
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Screening test methods for determination of fire spalling of concrete
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The fire resistance of concrete structures is generally good, but for some types of concrete fire spalling can reduce the fire resistance significantly. Therefore, methods are needed to predict whether a concrete will spall when exposed to fire and the severity of spalling.The objective of the present project was to develop an intermediate scale test method for the evaluation of the spalling behavior of concrete. The test method shall be cost effective and enable screening of different concretes before a full scale approval test is performed. A number of different intermediate scale test methods have been evaluated regarding the precision to reproduce the spalling behavior of that observed in full scale tests.Of the different test specimen shapes and methods, a circular test specimen where the concrete is casted in a steel tube has shown the best correlation to the full scale tests performed. This specimen is easy to produce, and the fire test can be performed on a small furnace.
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| 23. |
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| 24. |
- Gales, John, et al.
(författare)
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Fire research for timber structures
- 2023
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 47:4, s. 413-414
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 25. |
- Gernay, Thomas, et al.
(författare)
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Burnout resistance based on the Duration of Heating Phase concept – Literature Review and Roadmap
- 2024
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study focuses on the fire behavior of structural members considering their response until the end of the fire event. The study reviews and discusses a framework for determining the burnout resistance (B) of structural members through the Duration of the Heating Phase concept (DHP). This framework complements the fire resistance rating (FRR) system by providing a rating that captures the sensitivity to delayed structural failure during the cooling phase. The report describes experimental and numerical studies on concrete, timber, and steel members, highlighting substantial differences between their fire resistance rating, based on evaluation during the heating phase, and their burnout resistance, based on evaluation under the heating and cooling phases. With the burnout resistance as a complementary rating to fire resistance, a more holistic characterization of the safety and robustness of different structural solutions can be evaluated.
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| 26. |
- Jansson McNamee, Robert, et al.
(författare)
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The function of intumescent paint for steel during different fire exposures
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the present study the behaviour of four intumescent systems for steel was investigated experimentally. The main purpose of the study was to determine the behaviour of the systems during different fire scenarios including standardized furnace testing, tests in cone calorimeter and ad hoc tests including ceiling jets and fire plumes. The experimental campaign shows that two of the investigated systems did perform very poorly in the furnace tests compared to what they were designed for, despite being the systems having the best swelling in the cone calorimeter tests. This highlights the importance of adhesion at high temperature for this type of systems. Since adhesion is crucial a more relevant evaluation for this type of systems ought to be a test where the flows around the specimen can be characterized and controlled, i.e. a ceiling jet or a fire plume scenario. This is especially important as steel protected with intumescent systems are often used in large open spaces where local fire plumes and ceiling jets are expected.Key words: intumescent paint, steel, alternative exposure
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| 27. |
- Johansson, Nils, et al.
(författare)
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A Round Robin of Fire Modelling for Performance Based Design
- 2019
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Ingår i: 15th International Conference and Exhibition on Fire Science and Engineering : Interflam 2019 - Interflam 2019.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Nine participants, representing eight different Swedish fire consultancy firms participated in a Round Robin study where two different fire scenarios were simulated with the Fire Dynamics Simulator. The participants were given clear instructions on the building layout and heat release rate for the two scenarios. Still, the results demonstrate a significant variation in time to sprinkler system activation and available safe escape time, between the participants. It is important to emphasize that some degree of variation is unavoidable, as engineers can model things differently without the modelling solution necessarily being incorrect. Some of the variation seen in this study is however related to modelling choices that are questionable and consequently problematic for the reliability of the fire safety design.
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| 28. |
- Johansson, Nils, et al.
(författare)
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A Round Robin of fire modelling for performance-based design
- 2021
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 45:8, s. 985-
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Tidskriftsartikel (refereegranskat)abstract
- Nine participants, representing eight different Swedish fire consultancy firms participated in a Round Robin study where two different cases were simulated with the Fire Dynamics Simulator. The first case included a large open warehouse where the activation of a sprinkler system was to be studied. In the second case time to critical conditions in a theatre was to be calculated. The participants were given clear instructions on the building layout and heat release rate for the two cases. Still, the results demonstrate a significant variation in time to sprinkler system activation (range of 110 seconds) and available safe escape time (range of 60 seconds), between the participants. It is important to emphasise that some degree of variation is unavoidable, as engineers can model things differently without the modelling solution necessarily being incorrect. Even though it is hard to isolate and specific cause of the variation, some of the variation seen in this study is related to modelling choices that are questionable and consequently problematic for the reliability of the fire safety design. © 2020 The Authors.
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| 29. |
- Johansson, Nils, et al.
(författare)
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CFD-beräkningar vid brandteknisk dimensionering - En Round Robin studie
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I studien utförde nio deltagande aktörer samma beräkningsuppgifter utan att veta vad de andra kommit fram till. Resultatsammanställningen visar en relativt stor spridning som till största delen kan förklaras med att deltagarna gör olika ingenjörsmässiga val. Läs den och fundera på vilka ingenjörsmässiga val du gör i vardagen.
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| 30. |
- Johansson, Nils, et al.
(författare)
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CFD-beräkningar vid brandteknisk dimensionering - En Round Robin studie
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreningen för Brandteknisk IngenjörsVetenskap (BIV) har genomfört en s.k. Round Robinstudie inom beräkningsområdet CFD. I studien utförde nio deltagande aktörer samma beräkningsuppgifter utan att veta vad de andra kommit fram till. Resultat-sammanställningen visar en relativt stor spridning som till största delen kan förklaras med att deltagarna gör olika ingenjörsmässiga val.De två beräkningsfall som ingick i studien valdes för att utvärdera två olika processer, tiden till aktivering för ett sprinklersystem i en enkel geometri samt tiden till kritiska förhållanden för en lokal med komplex geometri. Vid beräkningarna av tid till aktivering var resultaten mellan 275 till 386 sekunder mellan deltagarna där deltagare F, G och H har kortare aktiveringstider jämfört med de sex andra deltagarna som var relativt lika. Huvudanledningen till denna spridning var att deltagare F och H använde FDS egen funktion för att beräkna sprinkleraktivering vilket i detta fall gav kortare tider än om man använder det separata programmet Detact-T2. Deltagare F och Ganvände också funktionen ”spread rate” och ett något högre värde än den föreskrivnatillväxthastigheten på 0,012 kW/s2 vilket också ledde till kortare aktiveringstider vilket inte är konservativt i detta fall. Beräkningsfall 2 var en beräkning av tid till kritiska förhållanden i en riktig byggnad. Vid denna beräkning ser vi stora skillnader i resultat. Tid till kritiska förhållanden för 10 meters sikt varierar mellan 63 och 124 sekunder medan motsvarande intervall för 5 meters sikt är 80-140 sekunder. Även här har några av deltagarna beskrivit branden på lite olika sätt i beräkningsmodellen, men det går inte att lyfta fram någon enskild parameter som orsak till den stora variationen.Den enda tydliga vägledningen som kan ges för tillfället är att man ska vara noggrann med hur man definierar branden. Det är svårt att dra några andra tydliga slutsatser från studien men den illustrerar hur komplexa riktiga scenarier blir och att fortsatt kartläggning av variationer vid beräkningar bör genomföras. Detta för för att vid behov förslå åtgärder för att minska osäkerheterna i resultat vilket tex krav på någon form av utbildning, certifiering, bättre vägledningsdokument etc.
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| 31. |
- Johansson, Nils, et al.
(författare)
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Façade Fires in Swedish School Buildings
- 2013
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Ingår i: MATEC web of conferances. - : EDP Sciences. - 2261-236X. ; 9, s. 03006-03006
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Fires outside school buildings caused by arson are a major problem in Sweden. The initial fire source can involve rubbish or other types of combustibles that can be found at or sometimes brought to the school. As the external fire develops the flames will extend along the façade. If the building is a one-story building, which is a common construction in Swedish school buildings, the fire can spread to the attic and further on to the rest of the building. A large research project was initiated in 2008 by the Swedish Fire Research Board in order to reduce the number and consequences of arson fires in school buildings. In this paper an evaluation of some technical systems that can be used to mitigate consequences of exterior fires is presented. The evaluation includes a literature review, experimental studies and a cost-benefit analysis. The study showed that some systems have clear cost-benefit advantages for the protection of school buildings in places where a high fire frequency can be expected.
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| 32. |
- Johansson, Nils, et al.
(författare)
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Technical measures to prevent and mitigate the consequences of arson in school buildings
- 2014
-
Ingår i: Fire Safety Science. - : International Association for Fire Safety Science. ; , s. 531-543
-
Konferensbidrag (refereegranskat)abstract
- Fires in school buildings caused by arson are a major problem in Sweden and in particular are the costs of these fires disproportionately high compared to the costs of fires in buildings in general. The Swedish Research Board initiated a multidisciplinary project in order to reduce the number and consequences of arson fires in schools. Both technical and social aspects have been dealt within this project. In this paper an overview of the findings of the sub-project related to technical issues are presented. The goal and purpose of it has been to evaluate technical systems and engineering solutions to prevent and reduce the consequences of arson in school buildings. As part of this has a number of issues been considered including: identification of typical fire scenarios and design fires, an inventory of available technical systems and solutions, small- And real-scale experiments and an extensive cost-benefit analysis of a selection of technical systems.
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| 33. |
- Karp, Melissa A., et al.
(författare)
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Increasing the uptake of multispecies models in fisheries management
- 2023
-
Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 80:2, s. 243-257
-
Tidskriftsartikel (refereegranskat)abstract
- Multispecies models have existed in a fisheries context since at least the 1970s, but despite much exploration, advancement, and consideration of multispecies models, there remain limited examples of their operational use in fishery management. Given that species and fleet interactions are inherently multispecies problems and the push towards ecosystem-based fisheries management, the lack of more regular operational use is both surprising and compelling. We identify impediments hampering the regular operational use of multispecies models and provide recommendations to address those impediments. These recommendations are: (1) engage stakeholders and managers early and often; (2) improve messaging and communication about the various uses of multispecies models; (3) move forward with multispecies management under current authorities while exploring more inclusive governance structures and flexible decision-making frameworks for handling tradeoffs; (4) evaluate when a multispecies modelling approach may be more appropriate; (5) tailor the multispecies model to a clearly defined purpose; (6) develop interdisciplinary solutions to promoting multispecies model applications; (7) make guidelines available for multispecies model review and application; and (8) ensure code and models are well documented and reproducible. These recommendations draw from a global assemblage of subject matter experts who participated in a workshop entitled “Multispecies Modeling Applications in Fisheries Management”.
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| 34. |
- Lange, David, et al.
(författare)
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Modelling of hollow core concrete construction exposed to fire
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report summarises the results of a project which was intended to study the response of hollow core and prestressed concrete construction exposed to fire. Two fires in the past 12 years highlighted the susceptibility of this type of construction to fire, a car park fire in Rotterdam and a department store fire in Vantaa. The car park fire has been extensively studied elsewhere and has led to much research on the response of hollow core construction exposed to fire. The department store fire has been less well reported.The report gives a short overview of these two fires, and then reports on a literature review of the response of prestressed and hollow core concrete construction exposed to fire. The comprehensive analyses carried out elsewhere are an excellent starting point for further study.The report then goes on to discuss the application of different concrete models to prestressed concrete construction. Other work reported elsewhere shows that results of modelling prestressed concrete construction exposed to fire is very susceptible to the concrete model which is used, and so finite element modelling of two fire tests of hollow core slabs is carried out to evaluate the impact of the concrete model on this type of construction. It is found that an explicit formulation of transient strain in concrete has a significant impact compared with an implicit formulation of transient strain, in the overall behaviour of the hollow core slab and also in the response of, e.g. the prestessing tendons.Finally, an analytical method for assessing the capacity of prestressed concrete construction under ambient conditions is extended to apply to hollow core slabs exposed to fire. This is used to compare the response of prestressed hollow core slabs to prestressed monolithic slabs exposed to fire and to study different parameters which influence the response and the capacity of hollow core units in fire.Based on the results of the analytical modelling, it can be seen that hollow core concrete construction experiences a far higher thermal gradient and resulting thermal moment than monolithic concrete construction. This is a result of the geometry of the cross section which effectively traps heat in the lower flange. This in turn leads to a faster loss of prestressing force on the cross section than in a monolithic concrete section. This contributes to a faster reduction in the ultimate moment of hollow core slabs compared with monolithic concrete construction.However changing the prestressing tendon depth has a significant effect on the evolution of the ultimate moment under fire exposure. A shallow tendon with little cover has higher capacity at ambient and under fire exposure for a short duration, whereas a tendon with a large amount of cover has a lower ambient capacity, but retains more of this capacity for longer under fire exposure.The analytical method which is proposed is not capable of capturing the nuances in behaviour and response of the finite element method which is reported, nevertheless it is useful in helping to understand the response of prestressed concrete construction exposed to fire. It may also be useful as a screening tool for evaluating the impact of different design options either in hollow core slabs themselves or when making choices in the design phase. However, both the analytical and the numerical modelling suffer from a lack of good quality experimental data which could be used for their evaluation and this should be considered in the future.Key words: prestressed concrete, hollow core slabs, fire, modelling
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| 35. |
- McNamee, Robert, et al.
(författare)
-
Brandspjälkning hos tunnelbetong – Fenomen och testmetoder
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fire spalling of concrete is a complex phenomenon with many influencing factors. The concrete mix, geometry and cross section, stress state, fire exposure, age, pre-conditioning, moisture state and the amount of spalling reducing polypropylene fibres added all influences in different ways if a fire exposed concrete structure is prone to spalling or not. During fire testing of concrete structures for tunnels it is in practice difficult to do fire test on real designs with real boundary conditions. Therefore, more or less representative test methods are used. If small test specimens are used, around 600 x 500 x 200 mm3, these tests are in general only indicative and shall mainly be used as “screening tests”, i.e. to optimise the mix before scaling up to more realistic sizes. Further on, the small test specimen size is not suitable for evaluating the fire resistance including heat penetration for longer duration of fire exposure as the geometrical and boundary effects are not representative for larger specimens.
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| 36. |
- McNamee, Robert, et al.
(författare)
-
Reduction of fire spalling of concrete with small doses of polypropylene fibres
- 2021
-
Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 45:7, s. 943-
-
Tidskriftsartikel (refereegranskat)abstract
- The addition of polypropylene (PP) fibres has been shown to reduce the fire spalling propensity of concrete. When including this type of fibres in the concrete, the concrete mix becomes less robust, and small deviations in the constitutes change the workability and properties of the concrete. So, from a manufacturing perspective as small dosages as possible of PP fibres are desirable. Very few large-scale fire resistance tests of concrete loaded in compression exist showing the function of PP fibres at low dosages on concrete mixes sensitive to spalling if no fibres are added. In this paper, results from 26 fire tests are presented and analysed. The test results are from four different experimental campaigns, but all the mixes have in common that the water-to-cement ratio is 0.40. The results show that an amount of only 0.6 kg/m3 PP fibres has a significant effect on the spalling propensity and that even lower amounts reduce the spalling although they do not eliminate it entirely. During one of the fire tests on large slabs loaded in compression, unloaded small cubes of the same mixes were also included in the furnace. None of the small specimens spalled, whereas some of the corresponding large slabs spalled beyond the layer of reinforcement. This illustrates that tests on small, unloaded specimens are not relevant when assessing fire spalling of larger cross-sections loaded in compression.
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| 37. |
- McNamee, Robert, et al.
(författare)
-
The development of façade fire testing in Sweden
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Façade fire testing has been high on the agenda worldwide due to the increased hazard of many occurrences of severe fire spread on façades. There is also international work going on to create a European standard for façade fire testing. In this context it is interesting to clarify what different national test methodologies are based on. This report is a review of the development that led to the Swedish standard for assessing fire performance of façades, SP Fire 105. The review starts from the development in the 1950s with assessing fire exposure from compartment fires and follows further development until 1990s. The fire exposure in the first edition of SP Fire 105 published 1985 was based on two test campaigns including external flames from room fires performed at Lund University during the late 70-ties and early 80-ties. In the early 90-ties the geometry of the air intake in the combustion chamber and the opening under the test specimen was slightly reduced leading to a lower effective thermal exposure of the façade than in the first edition of SP Fire 105. An important observation done already in the 1950s at the Swedish fire laboratory in Stockholm and in the late 1970s at Lund University was that the wind is influencing the test results when doing experiments outside.
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| 38. |
- Mohammadi Mohaghegh, Ali, 1980-, et al.
(författare)
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Fire Spalling of High-Performance Basalt Fibre Concrete
- 2017
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Ingår i: Nordic Concrete Research. - Oslo, Norway : nordic concrete federation. - 0800-6377. ; 57:2, s. 89-102
-
Tidskriftsartikel (refereegranskat)abstract
- The use of Macro Basalt Fibre Concrete (MBFC) for structural purposes is increasing in the Norwegian market. However, findings on properties related to fire spalling are scarce in the literature. Motivated by this, the authors present the results of a pilot experimental study on fire spalling properties of two types of basalt fibre concrete. The study results show that basalt fibres cannot prevent high-performance concrete (HPC) from fire spalling. Nonetheless, the comparison of the average spalling values indicates that use of basalt fibres probably does not increase the spalling propensity of the tested materials.
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| 39. |
- Nilsson, Markus, et al.
(författare)
-
A numerical comparison of protective measures againstexternal fire spread
- 2018
-
Ingår i: Fire and Materials. - : John Wiley & Sons. - 0308-0501 .- 1099-1018. ; 42:5, s. 493-507
-
Tidskriftsartikel (refereegranskat)abstract
- The impact of different passive protective measures against external vertical firespread was investigated using the numerical tool Fire Dynamics Simulator (FDS).The numerical study was divided into a validation study and a comparative analysis.The validation study was performed to evaluate FDS as a calculation tool for modellingexternal vertical fire spread and was conducted using experimental results from alarge‐scale fire test done on a SP FIRE 105 test rig at SP, Sweden. It was concludedthat FDS 6.2.0 could reproduce the experimental results with a reasonable level ofdetail. In the comparative analysis, the impact on the external fire from a smallerapartment was studied in FDS with different configurations of horizontal projectionsand spandrels in the building exterior. Also, the effects of an upper and lower facadeset‐back configuration were studied. The results show that facade solutions based ona horizontal projection or an upper facade set‐back configuration result in comparableor better protection compared with a defined spandrel height. The results also showthat a spandrel height of at least 1.2 m can be replaced by a 60‐cm‐deep horizontalprojection, given that the balcony is wider than the underlying opening.
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| 40. |
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| 41. |
- Runefors, Marcus, et al.
(författare)
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Influence of Sprinklers on the Thermal Exposure of a Tank Exposed to a Hydrogen Jet Flame
- 2022
-
Ingår i: Proceedings of the Tenth International Seminar on Fire and Explosion Hazards. - 9788272067211 ; , s. 248-257
-
Konferensbidrag (refereegranskat)abstract
- A high-pressure tank rupture is a challenging scenario requiring attention in most hydrogen applications. A common cause of rupture is an external fire heating the tank, causing increased internal pressure and/or reduction in the tensile strength of the tank material (with the relevance of each depending on tank material).Most of the available methods for prevention of such ruptures have been developed, primarily, for buoyancy-driven flames from nearby combustible materials. However, in some applications, a rupture due to heating from a hydrogen jet, emanating from a leak on the system, also needs to be prevented. One method, that has been used in some sites in Sweden, is to use a deluge water spray system to cool the exposed tank. However, this approach has not yet been experimentally validated. In this paper, a series of experiments are presented to assess the feasibility of such an approach. In the experiments a simulated tank is exposed to a small impinging hydrogen jet (Lf ≈ 1 m) while simultaneouslybeing cooled by a sprinkler system delivering water densities between 12.2 mm/min and 30.5 mm/min. The results show that, although the temperature at most of the tank surface becomes significantly lower due to the sprinkler, temperatures can locally remain much higher (ΔT ≈ 600-800K) which might still cause a rupture of a type-IV-tank. It is more likely that a sprinkler system can prevent rupture of a type-I-tank, but this has not been decisively proven.
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| 42. |
- Sandinge, Anna, et al.
(författare)
-
Wind turbine tower made of wood exposed to a campfire
- 2024
-
Ingår i: BOOK OF ABSTRACTS Nordic Fire & Safety. - : RISE Research Institutes of Sweden. - 9789189971080 ; , s. 25-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 43. |
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| 44. |
- Sjöström, J., et al.
(författare)
-
Anisotropic Curvature and Damage of Unbonded Post-tensioned Concrete Slabs During Fire Testing
- 2017
-
Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 53:3, s. 1333-1351
-
Tidskriftsartikel (refereegranskat)abstract
- Two furnace tests, using two different fire exposures, on unbonded post-tensioned concrete slabs (1700 × 1200 mm) are reported. Local curvature is measured along two lines approximately in the middle of the slabs both parallel (longitudinal) and orthogonal (transverse) to the prestressing direction. More pronounced curvature in the transverse direction is accompanied by the formation of cracks running predominantly in the longitudinal direction. While the transverse curvature relaxes back to the original state after the cooling phase the curvature in the longitudinal direction ultimately exhibits upward deflection due to the hogging moment caused by the prestress in the tendons acting on a cross section with temperature reduced mechanical properties at the fire exposed side. The effect on crack formation due to the prestressing can additionally be detected by ultrasonic pulse velocity measurements in the different directions through the depth of the slab, where a reduction of 5–25% is observed in the transverse direction compared to the longitudinal direction. The phenomenological mechanical behaviour of the slabs is captured in a finite element model which describes the evolution of stress in the prestressing tendons. This model additionally suggests that the curvature in the transverse direction is independent of the prestressing in the longitudinal direction. © 2016 Springer Science+Business Media New York
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| 45. |
- Sjöström, Johan, et al.
(författare)
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External fire plumes from mass timber compartment fires—Comparison to test methods for regulatory compliance of façades
- 2023
-
Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 47, s. 433-
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Tidskriftsartikel (refereegranskat)abstract
- Post-flashover fires inherently lead to external fire plumes, constituting a hazard for rapid fire spread over façades. As multi-storey mass timber buildings with internal visible timber surfaces become more common, there are concerns that such buildings would produce larger external plumes and hazards (assuming all other parameters equal). The literature reveals only indications of this, and how the actual exposure relates to different test methods for assessment is unknown. Here we utilise a series of full-scale mass timber compartment tests to quantify the exposure to the external façade. An incombustible external façade is instrumented with gauges at positions corresponding to reference data from several different assessment methods. The results show that there is an increase in plume duration, height, and temperatures when increasing the areas of exposed timber, but that this increase is less for normal- to large-opening compartments, than was previously seen in small-opening compartments. Also, normal variations in external wind speed have a larger influence on plume heights than the effect of doubling exposed timber surfaces. Test methods used for regulatory compliance differ significantly not only in exposure but also in pass/fail criteria. The proposed European large exposure method and the BS8414 method exhibit exposures on par with the severe end of what could be expected from mass timber compartments, whereas methods like SP Fire 105 and Lepir II produce significantly less severe plumes. However, the safety level is always a combination of exposure and assessment criteria. This data can help justify assessment criteria from a performance perspective. © 2023 The Authors.
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| 46. |
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