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Publications (10 of 59) Show all publications
Just, A., Brandon, D., Mäger, K. N., Pukk, R., Sjöström, J. & Kahl, F. (2018). CLT compartment fire test. 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.
Open this publication in new window or tab >>CLT compartment fire test
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2018 (English)In: WCTE 2018 - World Conference on Timber Engineering, 2018Conference paper, Published paper (Refereed)
Abstract [en]

New high-rise timber buildings are planned to be built in the near future all around the world. The fire protection concepts are not always considering natural fire scenarios. As timber is a combustible material, it can contribute to the fire within and outside of the fire compartment. For buildings with cross-laminated timber (CLT) elements the possible fall-off of lamellas should be considered because of the risk for second flashover, which can lead to a continuous fire. However, in case fire service interference or sprinkler activation is absent or inefficient, it may be necessary to design a building so that it leads to a decaying fire. Additionally, it is important to limit fire spread to neighbouring compartments. This paper discusses a compartment test of a two-story building made of CLT performed in Estonia to study delamination behaviour and consequences in compartments with realistic ventilation conditions. State-of-the art solutions to limit fire spread from the first floor into the second floor were applied. This involved robust design of connections, penetrations through the compartment boundary and the façade. The paper provides a description and analysis of the test.

Keywords
Compartment test, Cross laminated timber, Fall-off of lamella, Physically based fire, Fire protection, Floors, Laminating, Timber, Wooden buildings, Combustible materials, Compartment fires, Cross laminated, Fire compartments, Physically based, Protection concepts, Sprinkler activation, Fires
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36680 (URN)2-s2.0-85058162315 (Scopus ID)
Conference
2018 World Conference on Timber Engineering, WCTE 2018, 20 August 2018 through 23 August 2018
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-08-12Bibliographically approved
Östman, B., Schmid, J., Klippel, M., Just, A., Werther, N. & Brandon, D. (2018). Fire design of CLT in Europe. Wood and Fiber Science, 50, 68-82
Open this publication in new window or tab >>Fire design of CLT in Europe
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2018 (English)In: Wood and Fiber Science, ISSN 0735-6161, Vol. 50, p. 68-82Article in journal (Refereed) Published
Abstract [en]

The fire safety design of cross-laminated timber (CLT or X-Lam) in Europe is governed by the Construction Products Regulation and its essential requirements, as for all other building products. These requirements are mandatory, to be used in all European countries. They include classification systems for reaction to fire of building products, fire resistance of building elements, and structural Eurocodes. The reaction-to-fire performance of CLT in accordance with the European classification system is specified. Higher classes can be reached by chemical treatments, but the durability of the reaction-to-fire performance needs to be fulfilled according to a new European system. The fire resistance design of CLT building elements is not included in Eurocode 5, the structural Eurocode for timber, but can be either tested according to European standards or calculated by using design methods being developed recently. This article provides information about both reaction to fire and fire resistance of CLT in Europe. Furthermore, the importance of proper detailing in building design and in practice is stressed. Finally, performance-based design is introduced and some further research needs suggested.

Keywords
Building fires, Charring, Detailing, Fire resistance, Performance-based design, Reaction to fire, Architectural design, Building components, Codes (standards), Product design, Timber, Performance based design
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-35167 (URN)10.22382/wfs-2018-041 (DOI)2-s2.0-85051796991 (Scopus ID)
Available from: 2018-09-11 Created: 2018-09-11 Last updated: 2019-08-14Bibliographically approved
Brandon, D. & Just, A. (2018). Fire Safety of CLT Buildings with Exposed Wooden Surfaces. In: : . Paper presented at 4th Forum World Building Nordic Växjö.
Open this publication in new window or tab >>Fire Safety of CLT Buildings with Exposed Wooden Surfaces
2018 (English)Conference paper, Published paper (Other academic)
Abstract [en]

An increasing number of tall buildings made of CLT have been built in recent years. Current architectural trends involve having visible timber surfaces in these tall CLT structures. This results in new fire safety challenges, especially because fire service interference is increasingly difficult for increasingly tall buildings.

 

Recently, a number of research projects involving large scale compartment fire testing studied the development of fires in (1) compartments with a fully encapsulated CLT structure and (2) compartments with exposed CLT surfaces. The studies have shown that sufficient gypsum board protection can avoid the involvement of CLT in a fire. However, fall-off of the base layer of gypsum boards during can result in continuous fires that do not extinguish without fire surface interference, as during fall-off large areas of initially protected timber surfaces start to contribute as fuel to the fire.

 

If CLT is exposed to a fire, fire induced delamination of CLT (also lamella fall-off or char fall-off) could occur due to weakening of bond lines within the CLT. During fire induced delamination the exposed lamella falls from the CLT and a new relatively cold timber surface becomes exposed to potentially high temperatures, which effectively makes additional fuel suddenly available to a fire.

 

Very recent studies involved the development of CLT products that are not subject to delamination. The studies indicate that the use of (a) sufficient fire protection, (b) CLT products with thermally resistant adhesives and (c) a limit regarding the surface area of CLT that can be exposed, result in fires that decay and eventually self-extinguish.

This paper reviews the studies and includes a summary of conclusions.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36537 (URN)
Conference
4th Forum World Building Nordic Växjö
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2019-06-27Bibliographically approved
Brandon, D., Just, A. & Östman, B. (2018). Förslag för brandskydd i flervånings trähus.
Open this publication in new window or tab >>Förslag för brandskydd i flervånings trähus
2018 (Swedish)Report (Other academic)
Abstract [sv]

Denna rapport ger förslag på lösningar för brandskydd i höga trähus. De förslag som ges är inte fullständiga och andra åtgärder kan vara aktuella för att få till ett bättre brandskydd i höga trähus. De förslag som presenteras baseras på arbetet i forskningsprojektet

Brandskydd i höga trähus, som finansierats av Brandforsk (Brandforsk projekt 301-152) och Svenskt Trä och denna rapport är till stora delar en översättning av RISE report 2018:43 "Mitigation of fires in multi-storey timber buildings – statistical analysis and guidelines for design" av Daniel Brandon, Alar Just, Petra Andersson och Birgit Östman.

Brandnormer inriktas i första hand på personsäkerhet, men i höga och stora byggnader blir egendomsskyddet allt viktigare. De förslag som ges här baseras främst på analys av stora skador i USA. De viktigaste punkterna är att begränsa

1. Direkt brand- och rökspridning mellan brandceller via:

a. dörrar, väggar och bjälklag

b. anslutningar mellan byggnadselement

c. genomföringar i väggar och bjälklag

d. installationer i väggar och bjälklag

2. Brand- och rökspridning genom hålrum:

a. i brandcellsavskiljande byggnadselement

b. i fasader och yttertak

3. Utvändig brand- och rökspridning:

a. längs fasadens yta

b. genom fönster

c. genom ventilationsöppningar (t ex vid takfot)

d. på vindar

Publisher
p. 32
Series
RISE Rapport ; 2018:46
Keywords
brand, brandstopp, brandspridning, detaljlösningar, egendomsskydd, höga trähus
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38515 (URN)978-91-88695-86-4 (ISBN)
Available from: 2019-04-29 Created: 2019-04-29 Last updated: 2019-06-27Bibliographically approved
Brandon, D., Just, A., Andersson, P. & Östman, B. (2018). Mitigation of fire damages in multi-storey timber buildings: Statistical analysis and guidelines for design.
Open this publication in new window or tab >>Mitigation of fire damages in multi-storey timber buildings: Statistical analysis and guidelines for design
2018 (English)Report (Other academic)
Abstract [en]

The number of multi-storey timber buildings has increased during the last twenty years. Recent well-known fires in London, Dubai and Brazil, although not in timber buildings, have increased concerns regarding large fire spread and high damage fires. As timber is a combustible material, concerns have been expressed regarding property safety and it has been questioned whether fire damage is more significant in buildings with timber as the main structural material than in other types of buildings. This report includes a statistical study of data of fires in multi-storey timber buildings in New Zealand and an analysis of high damage fires that occurred in multi-storey timber buildings in the USA. The data from New Zealand showed no significant difference between share of fires that had flame damage out of the compartment of origin in (a) multi-storey timber buildings that were constructed in or later than 1992 and (b) other types of multi-storey buildings that were constructed in or later than 1992. Fires in multi-storey timber buildings that were constructed before 1992 spread more frequently to neighbouring compartments than fires in other multi-storey timber buildings constructed before 1992. Data of high damage fires occurring in multi-storey timber buildings in the USA indicated that outdoor fire spread is the most common cause for large fire spread. Additionally, the data indicates that high water damage is most often caused by fire service interference and is significantly less often related to sprinkler activation.

Based on the analysis of fire spread of high damage fires in the USA, guidelines are given in the report to limit (1) outdoor fire spread, (2) fire spread through cavities, and (3) fire spread directly from a fire compartment to a neighbouring fire compartment. A number of these guidelines were evaluated using a fire test of a two-storey timber structure.

Publisher
p. 47
Series
RISE Rapport ; 2018:43
Keywords
Tall timber buildings; Fire; Fire stop; Fire spread; Water damage
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:ri:diva-35110 (URN)978-91-88695-82-6 (ISBN)
Available from: 2018-09-03 Created: 2018-09-03 Last updated: 2019-06-27Bibliographically approved
Schmid, J., Klippel, M., Just, A., Frangi, A. & Tiso, M. (2018). Simulation of the Fire Resistance of Cross-laminated Timber (CLT). Fire technology, 54(5), 1113-1148
Open this publication in new window or tab >>Simulation of the Fire Resistance of Cross-laminated Timber (CLT)
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2018 (English)In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099, Vol. 54, no 5, p. 1113-1148Article in journal (Refereed) Published
Abstract [en]

Cross-laminated timber, typical abbreviations CLT or XLAM, is currently one of the most innovative product in building with wood. This solid engineered timber product provides advantages compared to other solid timber slabs as the dimension stability, i.e. swelling and shrinkage, is controlled by the crosswise laminations. As for other components, the fire resistance has to be verified for this type of product. While fire testing is time consuming and costly, simulations provide flexibility to optimize the product or to develop simplified design models for structural engineers. In this paper, a simulation technique is presented which can be used to determine the fire resistance of CLT. The technique was then used to develop simplified design equations to be used by engineers to predict the behavior of CLT in fire resistance tests and verify its fire resistance. Following existing models, the simplified design model aims for a two-step process whereby in a (i) first step the residual cross section and in (ii) a second step the load bearing capacity of the partly heated residual cross section is determined. The presented simulations consider the effective thermal–mechanical characteristics of wood exposed to standard fire and perform an advanced section analysis using a temperature profile corresponding to the actual protection and the location of the centroid together with the possibility of plasticity on the side of compression. It was shown that simulation results agree well with test results and that they can be used to determine layup specific modification factors used by the reduced properties method or zero-strength layers used by the effective cross section method. It was shown that the use of the zero-strength layers is favorable compared to the modification factors to calculate the resistance of the residual cross section. This is due to the large range of modification factors answering the typical layup of CLT comprising layers with their fiber direction cross the span direction. Subsequently, the methodology was used to determine design equations for initially unprotected and protected three-, five- and seven-layer CLT in bending and buckling. While the zero-strength layer for glulam beams in bending is assumed to be 7 mm (0.3 in), for CLT the corresponding value is in most of the cases between 5 mm and 12 mm but is different for other loading modes such as buckling (wall elements) and depending on the applied protection.

Keywords
Cross-laminated timber, Fire design model, Fire tests, Modelling, Structural fire design, Fire protection, Flammability testing, Laminating, Models, Product design, Timber, Cross laminated, Effective cross sections, Fire designs, Mechanical characteristics, Residual cross-section, Swelling and shrinkages, Fire resistance
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36569 (URN)10.1007/s10694-018-0728-9 (DOI)2-s2.0-85047904116 (Scopus ID)
Note

 Funding details: European Cooperation in Science and Technology, COST, FP1404

Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2019-06-27Bibliographically approved
Sterley, M., Noren, J., Liblik, J., Brandon, D. & Just, A. (2018). Small-scale test method for the fire behaviour of woodadhesive bonds in CLT. In: Book of abstracts of the final conference COST FP1404”Fire Safe Use of Bio-Based Building Products”: . Paper presented at COST FP 1404 Final Conference.
Open this publication in new window or tab >>Small-scale test method for the fire behaviour of woodadhesive bonds in CLT
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2018 (English)In: Book of abstracts of the final conference COST FP1404”Fire Safe Use of Bio-Based Building Products”, 2018Conference paper, Published paper (Other academic)
Abstract [en]

There is an increasing use of cross laminated timber (CLT) in the building sector. CLT is a wood panel product made from layers of solid lumber boards. Each layer of boards is oriented perpendicular to adjacent layers and glued on the wide faces of each board. It has been recognised that different adhesive systems have different behaviour in fire; especially that delamination behaviour of CLT can be avoided by choosing a suitable adhesive system. The best method for evaluation of the delamination is a full‐scale fire test, but considering the high costs of such tests, it is of the utmost importance to develop small‐scale methods for evaluating the adhesive bond properties in fire. The intention is that such small‐scale methods should provide the same results as full‐scale tests. A new, smaller scale method for classifying adhesives with respect to  fire properties would also simplify  the planning of  full scale  tests. Previous  tested small‐scale method for evaluation of finger joints is presented in (1).  In this study, a small‐scale fire test methodology for evaluation of CLT adhesive bond performance in  fire  is  introduced  (2).  The  aim  was  to  demonstrate  an  easy  tool  to  distinguish  between  fire resistant adhesive bonds and non‐fire‐resistant bonds, especially with respect to delamination. The cone heater of a cone calorimeter was used to carry out the tests. Cone calorimeter in accordance with ISO 5660 is one of the most widely used bench‐scale instrument in fire research. This small‐scale  device  has  several  advantages  over  larger‐scale  tests  thanks  to  its  fast,  simple  and  cost‐efficient manner to investigate basic material properties.  

Keywords
cross laminated timber, adhesives, delamination, fire performance, small‐scale test
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36538 (URN)
Conference
COST FP 1404 Final Conference
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2019-06-27Bibliographically approved
Nele Mäger, K. & Just, A. (2017). Development of Design Equations for Termoträ Fire Protect for the Component Additive Method.
Open this publication in new window or tab >>Development of Design Equations for Termoträ Fire Protect for the Component Additive Method
2017 (English)Report (Other academic)
Abstract [en]

This report details the development of effective thermal properties and design equations for Termoträ Fire Protect which can be used for the improved component additive method for fire design of timber structures.

Publisher
p. 29
Series
SP Rapport, ISSN 0284-5172 ; 2017:09
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-32790 (URN)
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2019-06-27Bibliographically approved
Nele Mäger, K. & Just, A. (2017). Development of Design Equations for the Component Additive Method for Paroc eXtra.
Open this publication in new window or tab >>Development of Design Equations for the Component Additive Method for Paroc eXtra
2017 (English)Report (Other academic)
Abstract [en]

This report details the development of effective thermal properties and design equations for Paroc eXtra which can be used for the improved component additive method for fire design of timber structures.  The results are validated with full scale fire tests where such reports are available. 

Publisher
p. 41
Series
RISE Rapport ; 2017:68
Keywords
stone wool, fire design, timber structures, component additive method, separating function
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33860 (URN)978-91-88695-37-6 (ISBN)
Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2019-06-27Bibliographically approved
Just, A. & Brandon, D. (2017). Fire Stops in Buildings.
Open this publication in new window or tab >>Fire Stops in Buildings
2017 (English)Report (Other academic)
Abstract [en]

In a statistical study performed by the London fire brigade in the Real Fires Database it was found that out of 30 086 fires occurring between 2009 and 2011, fire spread beyond the floor of origin through gaps or voids occurred in 92 cases. This illustrates that the phenomenon is relatively rare. However, it can lead to severe property damage. Fires can spread invisibly within cavities of the structure, which has led to problems concerning the extinguishment of the fire. Cavity barriers function is to stop the fire spread through cavities. However, these cavity barriers have not always been effective.

This report is the result of a study that aimed to:

1. Develop a robust testing method for cavity barriers for cavities with combustible materials within walls, floors and other elements in buildings.

2. Provide guidelines for the materials, installation, positioning, detailing and location of the cavity barriers.

Additionally, a preliminary study is performed to assess some extinguishing strategies.

Based on a study of characteristics of cavity fires, current standard fire tests for cavity barriers were revised for the use in cavities with combustible materials. From tests following the revised methodology, guidelines regarding the dimensions, installation and fire stopping design are provided.

Publisher
p. 34
Series
SP Rapport, ISSN 0284-5172 ; 2017:10
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-32784 (URN)
Note

Brandforsk project BF14-004

Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2019-06-27Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8001-401x

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