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Heidari, M., Robert, F., Lange, D. & Rein, G. (2019). Probabilistic Study of the Resistance of a Simply-Supported Reinforced Concrete Slab According to Eurocode Parametric Fire. Fire technology, 55(4), 1377-1404
Open this publication in new window or tab >>Probabilistic Study of the Resistance of a Simply-Supported Reinforced Concrete Slab According to Eurocode Parametric Fire
2019 (English)In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099, Vol. 55, no 4, p. 1377-1404Article in journal (Refereed) Published
Abstract [en]

We present the application of a simple probabilistic methodology to determine the reliability of a structural element exposed to fire when designed following Eurocode 1-1-2 (EC1). Eurocodes are being used extensively within the European Union in the design of many buildings and structures. Here, the methodology is applied to a simply-supported, reinforced concrete slab 180 mm thick, with a standard load bearing fire resistance of 90 min. The slab is subjected to a fire in an office compartment of 420 m2 floor area and 4 m height. Temperature time curves are produced using the EC1 parametric fire curve, which assumes uniform temperature and a uniform burning condition for the fire. Heat transfer calculations identify the plausible worst case scenarios in terms of maximum rebar temperature. We found that a ventilation-controlled fire with opening factor 0.02 m1/2 results in a maximum rebar temperature of 448°C after 102 min of fire exposure. Sensitivity analyses to the main parameters in the EC1 fire curves and in the EC1 heat transfer calculations are performed using a one-at-a-time (OAT) method. The failure probability is then calculated for a series of input parameters using the Monte Carlo method. The results show that this slab has a 0.3% probability of failure when the compartment is designed with all layers of safety in place (detection and sprinkler systems, safe access route, and fire fighting devices are available). Unavailability of sprinkler systems results in a 1% probability of failure. When both sprinkler system and detection are not available in the building, the probability of failure is 8%. This novel study conducts for the first time a probabilistic calculation using the EC1 parametric curve, helping engineers to identify the most critical design fires and the probabilistic resistance assumed in EC1. © 2018 The Author(s)

Keywords
Concrete, Monte Carlo, OAT method, Parametric temperature–time curve, Probabilistic analysis, Sensitivity analysis, Structural fire resistance, Structural reliability, Concrete slabs, Concretes, Failure analysis, Fire extinguishers, Fire fighting equipment, Heat transfer, Monte Carlo methods, Probability, Reinforced concrete, Reliability analysis, Sprinkler systems (fire fighting), Sprinkler systems (irrigation), Structural design, Structural fires, Time curves, Fire resistance
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34460 (URN)10.1007/s10694-018-0704-4 (DOI)2-s2.0-85044391165 (Scopus ID)
Available from: 2018-08-08 Created: 2018-08-08 Last updated: 2019-07-01Bibliographically approved
Honfi, D., Lange, D., Kozłowski, M., Sjöström, J. & Lenk, P. (2018). Behavior of load-bearing glass at elevated temperature. Paper presented at Volume 2, Issue 5-6ENGINEERED TRANSPARENCY 2018 Glass in Architecture and Structural Engineering. ce/papers, 2(5-6), 533-540
Open this publication in new window or tab >>Behavior of load-bearing glass at elevated temperature
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2018 (English)In: ce/papers, ISSN 2509-7075, Vol. 2, no 5-6, p. 533-540Article in journal (Refereed) Published
Abstract [en]

ABSTRACT The use of glass as a structural material has increased in the built environment over the last decades. Despite the large number of research projects and studies, it still poses difficulties in structural design. This particularly applies to the behaviour of glass in fire and under elevated temperatures since the available data on temperature dependent mechanical and thermal properties of glass is still limited. This contribution provides a brief overview of material properties of glass at elevated temperature and elaborates on current requirements for the fire safety included in standards.

Keywords
structural glass, elevated temperature, fire, structural design
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36097 (URN)10.1002/cepa.952 (DOI)
Conference
Volume 2, Issue 5-6ENGINEERED TRANSPARENCY 2018 Glass in Architecture and Structural Engineering
Available from: 2018-11-09 Created: 2018-11-09 Last updated: 2019-06-27Bibliographically approved
Petersen, L., Lundin, E., Sjöström, J., Lange, D. & Teixeira, R. (2018). Creating comparable public tolerance and technical performance measures for critical infrastructure resilience evaluation. In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018: . Paper presented at 28th International European Safety and Reliability Conference, ESREL 2018, 17 June 2018 through 21 June 2018 (pp. 1231-1240).
Open this publication in new window or tab >>Creating comparable public tolerance and technical performance measures for critical infrastructure resilience evaluation
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2018 (English)In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018, 2018, p. 1231-1240Conference paper, Published paper (Refereed)
Abstract [en]

No consensus currently exists on how to measure and evaluate Critical Infrastructure (CI) resilience. Attempting to use the public’s declared coping capacity as a target for CI resilience, this paper explores how to develop relevant resilience performance measurements that enable comparison to the tolerance levels of the general public. To do so, one must first establish the normal performance of the system and the applicable performance measures. Then, a survey is used to convert public perception into these measures as to enable comparison with the technical resilience performance. The CI resilience will be presented through a family of so-called resilience triangles which will illustrate the evolution of the performance, before, during and after a crisis event. A case study of the Municipal Water Network of Barreiro, Portugal, is used. The overall performance is preferably described with the categories quality, quantity and delivery. In quantifying the performance the importance of what is being assessed, to what hazard and for which end-user became evident.

Keywords
Public works, Reliability, General publics, Infrastructure resiliences, Municipal water networks, Performance measure, Performance measurements, Public perception, Technical performance measures, Tolerance levels, Critical infrastructures
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36679 (URN)2-s2.0-85058121346 (Scopus ID)9780815386827 (ISBN)
Conference
28th International European Safety and Reliability Conference, ESREL 2018, 17 June 2018 through 21 June 2018
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-06-27Bibliographically approved
Boström, L., Hofmann-Böllinghaus, A., Colwell, S., Chiva, R., Toth, P., Moder, I., . . . Lange, D. (2018). Development of a European approach to assess the fire performance of facades.
Open this publication in new window or tab >>Development of a European approach to assess the fire performance of facades
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2018 (English)Report (Refereed)
Abstract [en]

The objective of this project was to address a request from the Standing Committee of Construction (SCC) to provide EC Member States regulators with a means to regulate the fire performance of façade systems based on a European approach agreed by SCC.

Publisher
p. 312
Keywords
facade, fire performance, testing, BS8414, DIN 4102-20
National Category
Civil Engineering
Identifiers
urn:nbn:se:ri:diva-35189 (URN)10.2873/954759 (DOI)978-92-79-88000-1 (ISBN)
Funder
EU, European Research Council, SI2.743702 – 30-CE-0830933/00-14
Available from: 2018-09-25 Created: 2018-09-25 Last updated: 2019-06-27Bibliographically approved
Rosenqvist, H., Reitan, N. K., Petersen, L. & Lange, D. (2018). ISRA: IMPROVER societal resilience analysis for critical infrastructure. In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018: . Paper presented at 28th International European Safety and Reliability Conference, ESREL 2018, 17 June 2018 through 21 June 2018 (pp. 1211-1220).
Open this publication in new window or tab >>ISRA: IMPROVER societal resilience analysis for critical infrastructure
2018 (English)In: Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018, 2018, p. 1211-1220Conference paper, Published paper (Refereed)
Abstract [en]

Resilience of Critical Infrastructure (CI) has been a research focus for several years now, with efforts being made to develop methods for the analysis and assessment of CI resilience. However, these efforts are often carried out without consideration of enriching societal risk or resilience assessments with knowledge of the resilience of CI. Bearing in mind that the definition of CI according to the EU reflects the fact that it exists to deliver vital societal functions, the consideration of its resilience in isolation of the community it serves is only addressing part of the problem. The Horizon 2020 project IMPROVER has already developed methodologies for assessing and managing CI resilience. This paper proposes an evolution of the management framework for CI resilience which enriches societal resilience assessment with knowledge of the CI resilience. The framework and societal resilience analysis methodology are both described along with an application of the analysis method.

Keywords
Public works, Reliability, Safety engineering, Analysis method, Horizon 2020, Management frameworks, Research focus, Societal functions, Societal risks, Critical infrastructures
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36677 (URN)2-s2.0-85058135618 (Scopus ID)9780815386827 (ISBN)
Conference
28th International European Safety and Reliability Conference, ESREL 2018, 17 June 2018 through 21 June 2018
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-06-27Bibliographically approved
Bedon, C., Zhang, X., Santos, F., Honfi, D., Kozłowski, M., Arrigoni, M., . . . Lange, D. (2018). Performance of structural glass facades under extreme loads – Design methods, existing research, current issues and trends. Construction and Building Materials, 163, 921-937
Open this publication in new window or tab >>Performance of structural glass facades under extreme loads – Design methods, existing research, current issues and trends
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2018 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 163, p. 921-937Article in journal (Refereed) Published
Abstract [en]

Glass has been overwhelmingly used for windows and facades in modern constructions, for many practical reasons, including thermal, energy, light and aesthetics. Nevertheless, due to the relatively low tensile strength and mostly brittle behaviour of glass, compared to other traditional materials, as well as to a multitude of interacting structural and non-structural components, windows/facades are one of the most fragile and vulnerable components of buildings, being representative of the physical line of separation between interior and exterior spaces. As such, multidisciplinary approaches, as well as specific fail-safe design criteria and analysis methods are required, especially under extreme loading conditions, so that casualties and injuries in the event of failure could be avoided and appropriate safety levels could be guaranteed. In this context, this paper presents a review of the state of art on analysis and design methods in use for glass facades, with careful consideration for extreme loading configurations, including natural events, such as seismic events, extreme wind or other climatic exposures, and man-made threats, i.e. blast loads and fire. Major results of available experimental outcomes, current issues and trends are also reported, summarising still open challenges.

Keywords
Design standards and regulations, Extreme loads, Glass facades, Mitigation and protection, Structural glass, Vulnerability, Facades, Glass, Seismic design, Tensile strength, Design standard, Design
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33232 (URN)10.1016/j.conbuildmat.2017.12.153 (DOI)2-s2.0-85039871830 (Scopus ID)
Available from: 2018-02-12 Created: 2018-02-12 Last updated: 2019-06-27Bibliographically approved
Lange, D., Rush, D., Dai, X. & Boström, L. (2018). The Tisova fire test part 1: test report. Borås
Open this publication in new window or tab >>The Tisova fire test part 1: test report
2018 (English)Report (Other academic)
Abstract [en]

This report is a summary of the Tisova fire test, conducted in the Czech Republicin January 2015. It is the first of two reports into these test, and describes thebuilding, the experimental setup and discusses the results obtained on the day ofthe test. The results are discussed with a specific focus on the travelling nature ofthe fire in the building, since one of the objectives of the test was to provide anexperimental data set for validation of traveling fire models. To this end theproject was partially successful, since as is discussed a number of factorscontributed to slow fire spread and the need to alter the conditions of the testwhile it was ongoing by adding a mixture of diesel and gasoline to part of the fuelbed. This was needed in order to ensure that the test fulfilled the second of itsmain objectives – to provide a dataset of the response of a real structure exposedto a structurally challenging fire for the purposes of carrying out a round robinexercise of the response. This round robin will be reported in the second of thisreport series.Key conclusions from the test were that while we observed a travelling fire, thefire dynamics which lead to this and which contribute to the evolution of such afire need to be better understood.

Place, publisher, year, edition, pages
Borås: , 2018. p. 93
Series
RISE Rapport ; 2018:21
Keywords
Travelling fires, large scale testing, round robin, structural fire engineering
National Category
Civil Engineering
Identifiers
urn:nbn:se:ri:diva-35227 (URN)978-91-88695-56-7 (ISBN)
Funder
Brandforsk, 100-313
Available from: 2018-09-30 Created: 2018-09-30 Last updated: 2019-06-27Bibliographically approved
Lange, D., Rush, D., Bostrom, L., Wickström, U., Byström, A., Olsson, K. & Triantafyllidis, Z. (2018). The Tisova fire test part 2: heat transfer analysis. Borås
Open this publication in new window or tab >>The Tisova fire test part 2: heat transfer analysis
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2018 (English)Report (Other academic)
Abstract [en]

This report is the second of two reports into the Tisova fire test. It compares the results of three different groups’ attempts to model the temperature response of the structure in Tisova which was subject to a large scale travelling fire test. Generally it is observed that the different approaches have relatively close results, although one shows systematically hotter temperatures closer to the heated surface than the others; and differences between all three increase further from the heated surface.A comparison between the average calculated results and the experimental results is also shown for illustration. While an absolute comparison is not attempted because of experimental errors present the results do show the possible need for further data to support the heat transfer analysis required to carry out structural design for travelling fires.

Place, publisher, year, edition, pages
Borås: , 2018. p. 90
Series
RISE Rapport ; 2018:22
Keywords
Travelling fires, large scale testing, round robin, structural fire engineering
National Category
Civil Engineering
Identifiers
urn:nbn:se:ri:diva-35228 (URN)978-91-88695-57-4 (ISBN)
Funder
Brandforsk, 100-313
Available from: 2018-09-30 Created: 2018-09-30 Last updated: 2019-06-27Bibliographically approved
Schmid, J., Lange, D., Sjöström, J., Brandon, D., Klippel, M. & Frangi, A. (2018). The use of furnace tests to describe real fires of timber structures. In: WCTE 2018 - World Conference on Timber Engineering: . Paper presented at 2018 World Conference on Timber Engineering, WCTE 2018, 20 August 2018 through 23 August 2018. World Conference on Timber Engineering (WCTE)
Open this publication in new window or tab >>The use of furnace tests to describe real fires of timber structures
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2018 (English)In: WCTE 2018 - World Conference on Timber Engineering, World Conference on Timber Engineering (WCTE) , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Fire resistance is an important characteristic for all building structures regardless the building materials used. Methods for fire resistance testing were developed already before 1900 to measure the response of the structure in fire and compare different products. In the last decade, the increased popularity of timber buildings has led to a renewed interest in the performance of timber structures in fire and timber products were frequently tested in furnaces. Currently, some discussions question the validity of furnace test results for timber members which are carried out according to standards. Generally, it was stated that combustible and incombustible products are exposed to different thermal exposures when tested in furnaces or exposed in real fires. Additionally, some experts think that massive timber elements, e.g. cross-laminated timber (CLT), cannot be tested in furnaces as these products increase the fire load and, thus, statements in the framework of fire resistance testing are not possible. This paper investigates the validity of furnace resistance testing for combustible products and its limitations. It is shown that, firstly, the thermal exposure in fire resistance tests of incombustibles and combustibles is similar. Secondly, in addition to thermal exposure, the term fire exposure should be introduced where the oxygen concentration is described as the oxygen concentration significantly influences the behaviour of combustible material in fires. Thirdly, the furnace and compartment environment in flash-over fires is similar with respect to this fire exposure. Finally, it is not possible to directly use furnace test results to predict a compartment response in real fires including the cooling phase but recent investigations indicate that results from fire resistance tests can be used to predict burn-out when the mass loss of the timber specimen is measured.

Place, publisher, year, edition, pages
World Conference on Timber Engineering (WCTE), 2018
Keywords
Combustibility, Compartment fires, Fire resistance tests, Structures, Timber, Flammability, Furnaces, Oxygen, Structure (composition), Testing, Wooden buildings, Building structure, Combustible materials, Fire resistance test, Furnace resistance, Oxygen concentrations, Resistance testing, Timber structures, Fire resistance
National Category
Civil Engineering
Identifiers
urn:nbn:se:ri:diva-37312 (URN)2-s2.0-85056741746 (Scopus ID)
Conference
2018 World Conference on Timber Engineering, WCTE 2018, 20 August 2018 through 23 August 2018
Available from: 2019-01-18 Created: 2019-01-18 Last updated: 2019-06-27Bibliographically approved
Lange, D. & Boström, L. (2017). A round robin study on modelling the fire resistance of a loaded steel beam. Fire safety journal, 92, 64-76
Open this publication in new window or tab >>A round robin study on modelling the fire resistance of a loaded steel beam
2017 (English)In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 92, p. 64-76Article in journal (Refereed) Published
Abstract [en]

This paper details a round robin study of the calculated response of structures in fire. In this instance, the study is based on one of two fire tests which were conducted on steel beams in a horizontal fire resistance furnace. The two specimens in the tests were identical having come from the same cast flow. The tests were conducted according to EN 1365-3 and the steel beams had a total length 5.4 m, spanning 5.2 m. These tests also formed a part of a testing round robin, reported elsewhere. The calculations were conducted by round robin participants in two stages. In the first instance a prediction of the response was made without knowledge of the measured temperatures of the steel beam and with only the grade of steel and details of the test setup. In the second instance the participants were also given the measured elastic limit of the steel, which differed significantly from the elastic limit implied by the grade, as well as measured temperatures from the steel beam and the plate thermometers from the furnace and asked to refine their model. Statistical analysis of the round robin results are presented to illustrate the variation which arises in the results of calculations. The results of the round robin study serve to illustrate the fire research and testing community's capability for modelling this simple case as well as the uncertainty in the calculation results. The results of the calculation round robin are also compared with the testing round robin to illustrate the comparative certainty between testing and calculations.

Keywords
Calculations, Round robin, Structural fire engineering, Testing, Environmental testing, Fire resistance, Flammability testing, Steel beams and girders, Steel testing, Uncertainty analysis, Calculation results, Measured temperatures, Plate thermometers, Resistance furnaces, Round robin studies, Structures in fire, Routers
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-30807 (URN)10.1016/j.firesaf.2017.05.013 (DOI)2-s2.0-85020009581 (Scopus ID)
Available from: 2017-09-06 Created: 2017-09-06 Last updated: 2019-06-27Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4551-1045

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