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Just, A., Nurk, J. L. & Mäger, K. N. (2022). Improved fire design model for cross-laminated timber and glulam.
Öppna denna publikation i ny flik eller fönster >>Improved fire design model for cross-laminated timber and glulam
2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

Adhesives state the essential prerequisite for manufacturing large timber construction elements from rigidly bonded solid wood boards of growth and processing bound limited dimensions. In the first two decades after the invention of glulam up to the 1930s, adhesives based on natural organic substances like blood and proteins were used. Such adhesives can have high dry strength but are weak when applying water or temperature. These adhesives were then replaced by synthetic ones, firstly in the early 1930s by (phenol )-resorcinol-formaldehyde (RF/PRF) adhesives and then by urea-formaldehyde (UF) adhesives. Numerous tests have shown that the boiling water resistant duroplastic RF/PRF adhesives are very stable at high temperatures up to/beyond the charring of wood (Dorn and Egner, 1967; Klippel 2014). Contrary hereto, the UF adhesives later classified in Europe as type II adhesives have significantly reduced water resistance (e.g. Raknes (1997) and are less temperature stable and fire resistant, although the latter was not communicated sufficiently. The RF-, PRF- and UF- adhesives were exclusively used up until the 1980s when the presently existing timber standards for “cold” and fire design were being developed. From the 1980s onwards, adhesives with various chemical compositions have been added to the market. Firstly the duroplastic melamine-urea-formaldehyde and pure melamine formaldehyde (MUF/MF) adhesives, followed in the mid-90s by the moisture-hardening one-component polyurethane (1C-PUR) adhesives, then followed by the emulsion-polymer isocyanate (EPI) adhesives. In order to speed up curing times, being of utmost high economic importance, significant amounts of polyvinyl acetate (PVAc) have been added to the hardeners of MUF adhesives with drawbacks on temperature stability. Each of the developed adhesives has its advantages and disadvantages regarding strength, water and/or temperature resistance, application robustness and price. According to EN 1995-1-2:2004, chapter 3.5, the behaviour of a bond line in fire may not be considered explicitly if the bond line is made of phenol-formaldehyde and aminoplastic, Type I adhesives, according to EN 301. Regarding the general principle that adhesives shall produce joints of such strength that the integrity of the bond is maintained in the assigned fire resistance period, a footnote hints at the point that some adhesives show softening considerably below the charring temperature of wood.

Förlag
s. 10
Serie
FIRENWOOD D2.3
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61175 (URN)978-91-89757-10-3 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue byGermany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR)project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); SwedishGovernmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway(Research Council of Norway (RCN) project number 298587). Fores tValue has received funding fromthe European Union's Horizon 2020 research and innovation programme under grant agreement No773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Mäger, K. N. & Just, A. (2022). Improved fire design model for walls and floors with I-joists.
Öppna denna publikation i ny flik eller fönster >>Improved fire design model for walls and floors with I-joists
2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

Wooden I-joists, being factory-made ultra-light and highly optimised products, are typically used as the load-bearing elements in timber frame assemblies (TFA), which consist of a combination of material layers – sheeting boards (claddings) and cavities which may be partially or completely filled with insulation. The materials used in conjunction with a timber member in a TFA affect the heating of the timber member. The joists consist of flanges (made of sawn wood, LVL or glulam) and a web (made of a wood - based board). Fire resistance of such wooden structural products is a complex matter. However, the current European design standard for timber structures in fire – Eurocode 5 Part 1-2 (2004) provides no guidance for I-joists. The fire resistance of wooden I-joists has been previously investigated by König (2006) and Schmid et al. (2011), who developed calculation models to analyse the load-bearing capacity of wooden I-joists exposed to fire for floors. There have been significant changes in the variety and types of materials used in conjunction with I-joists. Therefore, the application of these models is limited nowadays. Additionally, they focus on the reduced properties method. Only the effective cross-section method will be included in the revised Eurocode 5 Part 1-2. This report describes the unified model for wooden I-joists in both wall and floor assemblies which follows the philosophy of the effective cross-section method. Additionally, it should be used with all types of cavity insulation and fire protection systems. The unified I-joists model aims to be introduced to the new revised Eurocode 5 Part 1-2. Two phenomena have to be considered according to the ECSM: charring and mechanical resistance. It is assumed that the charring of wood is a material characteristic which is not dependent on the orientation of the structure (wall or floor). The charring of the flanges is primarily dependent on the cladding material and thickness. After the failure of the claddings, the charring is influenced by cavity insulation. Gypsum plasterboards as cladding and stone and glass wool as cavity insulation have been tested and analysed. A large number of thermal simulations have been analysed to investigate the influence of various factors (e.g. flange size, cavity insulation material, protective boards) on the charring behaviour of the fire-exposed flange and the web. The combination of different materials and the slender nature of I-joists makes their fire resistance a complicated issue. The thin web is very sensitive to elevated temperatures and charring. Additionally, adhesives used in finger joints in the flanges and the joint between the flanges and the web influences the load-bearing capacity. The loss of strength and stiffness were seen in wood at elevated temperatures is considered in the ECSM by a zero-strength layer. The zero-strength layer (ZSL) is an additional reduction of the cross-section to compensate for the decrease in strength and stiffness properties. The development of the expressions to calculate the ZSL depths for compression elements is discussed in this paper.

Förlag
s. 14
Serie
FIRENWOOD D2.2
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61176 (URN)978-91-89757-09-7 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue byGermany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR)project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); SwedishGovernmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway(Research Council of Norway (RCN) project number 298587). Fores tValue has received funding fromthe European Union's Horizon 2020 research and innovation programme under grant agreement No773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Olofsson, R., Mäger, K. N. & Just, A. (2022). Large-scale fire tests of engineered wood systems.
Öppna denna publikation i ny flik eller fönster >>Large-scale fire tests of engineered wood systems
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2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

This report presents the four large-scale fire tests performed within the FIRENWOOD project. The aim of the tests was to verify the improved fire design models for the I-joists and crosslaminated timber. The results of the loaded floor test with cross-laminated timber were also compared with results from an unloaded model-scale test with similar lamella thicknesses and adhesive. The aim of the compartment fire test was to study the behaviour of I-joists in physically based fire compared to the behaviour in standard fire. The second aim was to compare the fire behaviour of the compartment made of timber frame assemblies with I-joists and the previously performed similar compartments made with CLT. All large-scale tests reported here were performed with engineered wood structures using adhesive No.9

Förlag
s. 86
Serie
FIRENWOOD D3.6
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61177 (URN)978-91-89757-14-1 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue byGermany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR)project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); SwedishGovernmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway(Research Council of Norway (RCN) project number 298587). ForestValue has received funding fromthe European Union's Horizon 2020 research and innovation programme under grant agreement No773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-11-01Bibliografiskt granskad
Olofsson, R., Just, A., Mäger, K. N. & Sterley, M. (2022). Loaded fire tests with I-joists.
Öppna denna publikation i ny flik eller fönster >>Loaded fire tests with I-joists
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2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

The aim of the tests was to evaluate the potential reduction of the moment capacity of I-joists caused by bondline integrity of the finger joints. Each I-joist was made with 11 different adhesives in the finger joints in tension flange. All the adhesives were from Firenwood selection. Finger joints in tension may show a lower load-bearing capacity in the fire situation depending of the bond line integrity in fire. I-joists were loaded in bending with the tension flange being closer to the fire. I-joists were protected with gypsum plasterboard during the entire fire test. Cavities of the test assembly were filled with stone wool.

Förlag
s. 50
Serie
FIRENWOOD D3.2
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61178 (URN)978-91-89757-11-0 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue byGermany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR)project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); SwedishGovernmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway(Research Council of Norway (RCN) project number 298587). ForestValue has received funding fromthe European Union's Horizon 2020 research and innovation programme under grant agreement No773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Olofsson, R., Just, A. & Sterley, M. (2022). Model scale fire tests with cross-laminated timber.
Öppna denna publikation i ny flik eller fönster >>Model scale fire tests with cross-laminated timber
2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

The aim of the fire tests presented in this report was to measure the mass loss and the charring depth of CLT (cross-laminated timber) elements with different types of adhesives when exposed to fire from below. CLT elements may heat delaminate when exposed to heat. If this occurs, it depends, among other things, on the temperature of the adhesive and on the adhesive’s ability to retain its adhesive properties. Eleven adhesives are used in FIRENWOOD project in order to compare properties in fire. Adhesives originate from four different chemical backgrounds and represent the state of the art of adhesives used in timber structures. Adhesives are manufactured by 4 leading European adhesive manufacturers, and all 11 adhesives have passed requirements in European standards for load-bearing timber structures. Adhesives are marked with numbers 1 to 12 (adhesive no 10 is not included in this Work Package). Not all adhesives were tested for this method and is therefore not presented in the results.However, some additional adhesives were used in the tests presented in this report and are marked 21, 22, 23 and 24. The same numbers are used for all adhesives in all tests throughout FIRENWOOD project.

Förlag
s. 25
Serie
FIRENWOOD D3.5
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61179 (URN)978-91-89757-13-4 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue by Germany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR) project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); Swedish Governmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway (Research Council of Norway (RCN) project number 298587). ForestValue has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Sterley, M., Olofsson, R., Nurk, J. L. & Just, A. (2022). Small-scale tests with adhesive bonds with CLT, GLTand finger joints.
Öppna denna publikation i ny flik eller fönster >>Small-scale tests with adhesive bonds with CLT, GLTand finger joints
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2022 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

Wood construction is growing rapidly and provides a substantial contribution to the development of a more sustainable construction sector. Several modern wood-based building systems are developed with a focus on tall wooden houses and industrial production, where glued products are an important part. Fire safety is important, but the adhesive properties in fire conditions are not fully understood. This applies in particular to new adhesive systems but also to existing ones that exhibit poor load carrying capacity in a fire. The problem has been noted by the FSUW (Fire Safe Use of Wood) global network, which formed a sub-group of “Glue-line failure of engineered wood products” with representatives from Australia, NZ, Canada, USA, France, Italy, Switzerland, Sweden, and Germany. The global network has gathered knowledge and experience from known cases of fire testing of glued wood components (especially glulam, finger joints, and CLT) and has defined research needs. The results highlighted by this group relate to the delamination of glued bonds in a fire which can cause increased charring of glued wood products, especially for CLT. The results show that the temperature during standard fire testing increases continuously without cooling phase and with delamination of CLT until a collapse of the structure occurs. Thicker CLT may be required to reduce delamination risks or to protect the wood material. This can lead to increased costs and greater weight of the construction as well as reduced possibility of using visible wood. Therefore, it is of the utmost importance to find methods for evaluating the adhesive bond properties in a fire. The hypothesis is that different adhesive systems have different behaviour in fire, and especially that delamination behaviour can be avoided by choosing a suitable adhesive system. The best method for the evaluation of fire delamination is a full-scale test, but considering the high costs of such full-scale tests, a smaller-scale test needs to be developed. The intention of FIRENWOOD project is that such small-scale methods should give the same results as full-scale tests. A new, smaller-scale method for classifying adhesives concerning fire properties would also simplify the planning of full-scale tests. In Work Package 3 of FIRENWOOD project, some small-scale fire testing methods for adhesive bonds were evaluated at RISE, and this report includes results from small-scale fire tests of adhesive bonds in finger joints, CLT and GLT. The report is organized in three chapters based on the three different products tested. The common for all three tests was that the same eleven adhesive systems were used in all adhesive bonds.

Förlag
s. 26
Serie
FIRENWOOD D3.3
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:ri:diva-61180 (URN)978-91-89757-12-7 (ISBN)
Anmärkning

The FIRENWOOD project is supported under the umbrella of ERA-NET Cofund ForestValue byGermany (Federal Ministry of Food and Agriculture (BMEL); Agency for Renewable Resources (FNR)project number FKZ 2219NR120), Sweden (The Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning (FORMAS); Swedish Energy Agency (SWEA); SwedishGovernmental Agency for Innovation Systems (Vinnova) project number 2018-04989) and Norway(Research Council of Norway (RCN) project number 298587). ForestValue has received funding fromthe European Union's Horizon 2020 research and innovation programme under grant agreement No773324.

Tillgänglig från: 2022-11-18 Skapad: 2022-11-18 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Sæter Bøe, A., Nele Mäger, K., Leikanger Friquin, K. & Just, A. (2021). FRIC Webinar : Charring of wooden I-joists in assemblies with combustible insulation.
Öppna denna publikation i ny flik eller fönster >>FRIC Webinar : Charring of wooden I-joists in assemblies with combustible insulation
2021 (Engelska)Övrigt (Övrigt vetenskapligt)
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-56734 (URN)
Anmärkning

ID nummer «FRIC webinar D3.1-2021.05c»

Tillgänglig från: 2021-10-04 Skapad: 2021-10-04 Senast uppdaterad: 2024-04-09Bibliografiskt granskad
Mäger, K. N., Just, A., Sterley, M. & Olofsson, R. (2021). Influence of adhesives on fire resistance of wooden i-joists. In: World Conference on Timber Engineering 2021, WCTE 2021: . Paper presented at World Conference on Timber Engineering 2021, WCTE 2021, 9 August 2021 through 12 August 2021. World Conference on Timber Engineering (WCTE)
Öppna denna publikation i ny flik eller fönster >>Influence of adhesives on fire resistance of wooden i-joists
2021 (Engelska)Ingår i: World Conference on Timber Engineering 2021, WCTE 2021, World Conference on Timber Engineering (WCTE) , 2021Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

FIRENWOOD is an Era-NET cofund Forest Value project (2019-2022) dealing with the fire resistance testing and design methods of engineered wood products at elevated temperatures and fire. As one part of the project, various adhesives, allowed for load bearing timber structures, are tested in finger joints in small scale and medium scale fire tests. The paper will provide a description of these tests and an overview and analysis of the results. Based on the test data of both types, a good agreement regarding the adhesive performance between the tests can be shown. The design model for wooden I-joists is described and values for the depth of the zero-strength layer are proposed for different adhesive performance levels in finger joints.

Ort, förlag, år, upplaga, sidor
World Conference on Timber Engineering (WCTE), 2021
Nyckelord
Adhesive bonds, Engineered wood products, Fire resistance, Fire testing, I-joists, Adhesives, Building materials, Composite materials, Flammability testing, Product design, Wood products, Adhesive bond, Adhesive performance, Design method, Elevated fires, Elevated temperature, Finger joints, I-joist, Resistance testing, Testing method
Nationell ämneskategori
Trävetenskap
Identifikatorer
urn:nbn:se:ri:diva-57345 (URN)2-s2.0-85120750066 (Scopus ID)
Konferens
World Conference on Timber Engineering 2021, WCTE 2021, 9 August 2021 through 12 August 2021
Anmärkning

Funding details: Eesti Teadusagentuur, ETAg, PRG820; Funding text 1: The authors would like to acknowledge the ERA-Net cofund initiative and the national bodies for supporting this research. This work was supported by the Estonian Research Council grant (PRG820). The authors would like to thank Masonite Beams and the adhesive producers for their material, knowledge and support. The authors would like to thank laboratory personnel at RISE Fire Research in Trondheim for performing the tests within the limited conditions caused by Covid-19.

Tillgänglig från: 2021-12-29 Skapad: 2021-12-29 Senast uppdaterad: 2023-05-08Bibliografiskt granskad
Brandon, D., Landel, P., Ziethen, R., Allbrektsson, J. & Just, A. (2019). High-Fire-Resistance Glulam Connections for Tall Timber Buildings.
Öppna denna publikation i ny flik eller fönster >>High-Fire-Resistance Glulam Connections for Tall Timber Buildings
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2019 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

Tall timber buildings generally require fire resistance ratings of 90 minutes, 120 minutes or more. The vast majority of fire tested structural timber connections, however, did not reach a fire resistance that was relevant for these buildings. Commonly timber connections between glued laminated timber members comprise of exposed steel fasteners, such as bolts, screws, nails and dowels. However, it has previously been concluded that connections with exposed steel fasteners, generally do not achieve fire resistance ratings of 30 minutes and are, therefore, inadequate to be implemented in tall timber buildings without fire encapsulation. The research project presented in this report consists of four connection fire tests that are designed to achieve structural fire resistance ratings of 90 minutes, using different design strategies. This goal was achieved for all tested column-beam connections. A single test of a moment resisting connection did not lead to a fire resistance rating of 90 minutes, due to timber failure at the smallest cross-section after 86 minutes. The low temperature of the steel fasteners and the limited rotation of the connection, however, suggest that the connection would have been capable of achieving a 90 minutes fire resistance rating if larger beam cross-sections would be used.

Serie
RISE Rapport ; 2019:26
Nationell ämneskategori
Husbyggnad
Identifikatorer
urn:nbn:se:ri:diva-59183 (URN)978-91-88907-52-3 (ISBN)
Tillgänglig från: 2022-05-09 Skapad: 2022-05-09 Senast uppdaterad: 2023-06-07Bibliografiskt granskad
Mäger, K. N., Just, A., Schmid, J., Werther, N., Klippel, M., Brandon, D. & Frangi, A. (2019). Procedure for implementing new materials to the component additive method. Fire safety journal, 107, 149-160
Öppna denna publikation i ny flik eller fönster >>Procedure for implementing new materials to the component additive method
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2019 (Engelska)Ingår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 107, s. 149-160Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The performance of light timber frame wall and floor assemblies in fire depends on their composition. The assemblies' ability to form fire-separations between building compartments (separating function) can be assessed by full-scale fire testing or calculation methods. Calculations are the low cost and more flexible alternative.The component additive method is a commonly used calculation method for fire design of timber structures. The method considers the insulation ability of the material layers present in the assembly. The component additive method described in this article is developed to be flexible to implement different materials and products of different dimensions. However, the amount of different materials currently included in this method is rather limited and there is no generally accepted procedure to implement new materials.This paper presents a common agreement of the procedure to implement new materials which comprises of: (1) the design and execution of model-scale fire tests; (2) determination of the modified thermal properties needed for simulations; (3) thermal simulations of assemblies in fire conditions; (4) development of design equations and; (5) verification by one or more full-scale fire test(s). The abovementioned steps have been clearly presented in this paper and supported by examples.

Nyckelord
Component additive method, Fire safety design, Fire tests, Thermal simulations, Timber structures, Ability testing, Fire protection, Fires, Flammability testing, Timber, Additive methods, Fire safety designs, Structural design
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:ri:diva-33164 (URN)10.1016/j.firesaf.2017.09.006 (DOI)2-s2.0-85029795034 (Scopus ID)
Tillgänglig från: 2018-01-23 Skapad: 2018-01-23 Senast uppdaterad: 2023-05-16Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0002-8001-401x

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