| 1. |
- 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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| 2. |
- 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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| 3. |
- 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
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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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| 4. |
- Sjöström, J., et al.
(författare)
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Anisotropic Curvature and Damage of Unbonded Post-tensioned Concrete Slabs During Fire Testing
- 2017
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Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 53:3, s. 1333-1351
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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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