9th  On-line webinar 
2 Nov 2020, 9:00 - 3 Nov 2020, 22:00 (CET)

Conference Program

 


 

Keynote speakers

 

Society of Wood Science and Technology (SWST) – A Bridge Linking Academia, Community, Industry and Government; Overview of Fire Research in the US

Eva Haviarova
Purdue University, USA
Past President of International Society of Wood Science & Technology (SWST), USA

Abstract: Society of Wood Science and Technology is internationally recognized professional organization of wood scientists, engineers, marketing specialists and other professionals concerned with research, use, management, innovation, and value adding to lignocellulosic materials, as well as their protection and preservation. Society has rich history and vast accomplishments. Our members promote wise use of lignocellulosic materials, while making sure that we protect our forest resources through development of new ideas and procedures. SWST is establishing forums for exchange of innovative ideas, communication of knowledge and development of high standards for wood related research. Fostering quality education at all levels of wood science is one of its most impotent goals. SWST continues in internationalization and is open to engage with new partners and new members. This presentation will explain major benefits and services of the society.

Abstract: Forest fires are real threats not only in the US but also worldwide. Recent uncontrolled US forest fires, powered by strong winds and scorching temperatures are reminding us that forest fires mitigating strategies are urgently needed. We have to accept that forest fires themselves cannot be stopped; they are fueled by climate change, layered on top of an ecosystem that burns regularly as part of its natural cycle, accumulated woody biomass, as well as housing developments in areas that are ecologically supposed to burn. Mass timber movement is also reinforcing importance of fire research. Forestry and forest products research community how to address variety of undesirable fire issues with relevant research. Fire research in the US is categorized into three primary research areas: Structures and Contents, Wildland Fire, and Firefighter Safety. This presentation will describe important US research units, research laboratories, standards and fire related research conducted in some of these research canters.

 

Australian Building Code Change - Eight-Storey Timber Buildings

Boris Iskra
Forest and Wood Products Australia, Melbourne, Australia

Abstract: Changes introduced in the 2016 edition of the Building Code of Australia permitted residential and office buildings to be of timber-framed or massive timber construction up to 25 m in effective height as a Deemed-to Satisfy solution for the first time; typically, eight-storeys. This approach was extended in the 2019 edition of the BCA, to all classes of buildings – including retail premises, schools, hospitals and aged-care buildings of timber-framed and massive timber construction. Detailed fire engineering modelling and multi-scenario analyses supplemented by full-scale fire testing were undertaken as part of the BCA approval process which compared the risk-to-life achieved by fire protected timber buildings to that of similar buildings (reference cases) constructed using noncombustible forms of construction. The analysis considered factors such as the frequency of potential flashover fires, effectiveness of automatic fire sprinklers, barrier (wall, floor/ceiling) performance, enclosure heating regime, occupant behaviour and fire brigade intervention. The analysis demonstrated that structural timber building elements (wall frame, floor/ceiling, shafts) protected by specified fire-protective grade plasterboard coverings can achieve a higher level of safety than traditional non-combustible construction.

 

Flame retardancy of wood-plastic composites by radiation-curing phosphorus-containing resin

Rodolphe Sonnier
IMT Mines Alès, France

Abstract: Wood-plastic composites were prepared by impregnating softwood and tropical hardwood by a radiation-curing resin containing phosphorus or chlorine groups as flame retardant. Microscopic observations revealed that the heterogeneous impregnation depends on the density but also on the wood species and sample orientation. Physical properties (hardness, stiffness, conductivity, moisture content) of the unmodified woods and their resin-impregnated counterparts were examined and correlated with their densities. The flame retardancy was investigated by cone calorimeter tests. Although the incorporation of the resin is detrimental flame retardancy, the addition of phosphorus or chlorine groups allows a decrease in flammability. Phosphorus-containing resins limit the smoke release in comparison to chlorine-containing resin. Finally, the denser wood-plastic composites exhibit improved mechanical properties without increasing the flammability in comparison with their unmodified woods counterparts.

 

Fabrication and Characterization of Flame-Retardant Nano-Composites

Hyun-Joong Kim
Lab. of Adhesion & Bio-Composites, Environmental Materials Science, Seoul National University, Republic of Korea

Abstract: Clay is a substance that is abundant in nature. Exfoliation of clay is important for its use as a nanomaterial. The surface modified clay is dispersed in a polymer through a solvent method or melting method. When a high specific surface area is characteristic of a nanomaterial and a nanoclay polymer composite is exposed to the fire, it will exhibit excellent flame retardancy properties. When the polymer is exposed to heat, decomposition occurs, and intermediate products can move to the combustion surface, where they can be combusted if met with oxygen. However, nanoclays delay such movement. Thus, total heat release rate is constant, but the maximum heat release rate is low, as the results showed. These features are identified objectively by using the cone calorimeter. The results showed that organic flame retardants interact with the dispersed nanoclays, and the restacking structure of nanoclays form in their influence. When the thermal decomposition of the nanoclay organic flame retardant polymer composite occurs, a micro-nanostructure is formed, which prevents the intermediate material from being moved to the combustion surface, thus reducing the maximum heat release rate.

 


 

Structure and Properties of Wood and Its Changes at High Temperatures

 

Small Scale Test to Measure the Strength of Adhesives at Elevated Temperatures for Use in Evaluating Adhesives for Cross Laminated Timber (CLT)

Samuel L. Zelinka1, Byrne Miyamoto2, Nathan J. Bechle1, and Douglas Rammer1
1 USDA Forest Service Forest Products Laboratory, Madison, USA
2 Oregon State University, Corvallis, USA

Abstract. Cross laminated timber (CLT) is becoming widely available in North America. The product standard for North American CLT, PRG-320, has strict requirements on adhesive performance under fire scenarios. To become an adhesive certified under PRG-320, a full sized CLT compartment must be built and tested without a second flashover occurring caused by delamination. Currently, only three adhesive formulations are PRG-320 certified. This large scale test is expensive to run and only yields “pass-fail” results. In this paper we present small-scale adhesive tests performed at the Forest Products Laboratory. The tests examine a single lap shear joint. The samples are tested at elevated
temperatures in a universal testing machine with an environmental chamber built around the grips. The strains are measured using digital image correlation. Tests were conducted in two different manners. In the first test, thermal equilibrium was achieved and the sample was loaded to failure. In the second test, a constant load was applied and a thermal ramp was applied until failure occurs and the temperature at failure was recorded. Importantly, the tests were compared against control samples of solid wood (no adhesive) so that adhesive strength could be normalized to that of solid wood. It is hoped that this small-scale test can aid in the understanding of CLT adhesive performance and be used to screen adhesives prior to investment in large scale adhesive qualification tests.

 

Experimental Study of the Combustion of a Single Biomass Particle

Pahola Acevedo, Angel Martinez, Corine Lacour, and Alexis Coppalle
Normandie Univ, INSA Rouen, UNIROUEN, CNRS, CORIA, France

Abstract. Biomass valorization for energy production is considered as one of the best ways to overcome the petroleum’s depletion, move forward in the environmental protection concerns, but also to provide the energetic request. The combustion of biomass is an efficient valorization pathway but it still requires fundamental knowledge. To go deeper, some authors use simulation analysis combined with experimental results where a good agreement is appreciated. In the same sense, the present study explores experimentally the combustion of a single biomass particle as woody pellets and wood. An experimental free-ventilated system is built with a cone calorimeter as radiative
heat source in order to heat the particles. A weighing scale is used to measure mass degradation during combustion process, and a type-k thermocouple allows measuring the temperature evolution in the center of the particle. As a result, curves of temporal evolution of mass degradation and central temperature are acquired for each kind of particle. This allows to observe the three main phases of combustion process (particle drying, volatiles combustion, and char’s combustion), besides a superposition of homogeneous and heterogeneous combustions phases. Considering that the elemental composition of woody pellet and wood particles are close, similar combustion phases are identified with different
time steps.

 

Characterization of Wood Chemical Changes Caused by Pyrolysis During Flaming Combustion Using X-Ray Photoelectron Spectroscopy

Laura E. Hasburgh1, Donald S. Stone2, Samuel L. Zelinka1, and Nayomi Z. Plaza1
1 US Forest Products Laboratory, Madison, USA
2 Materials Science and Engineering, University of Wisconsin, USA

Abstract. As heat is applied to wood, thermal degradation, called pyrolysis, occurs. A majority of what is known about the pyrolysis of wood has been obtained using either extracted component polymers or wood pyrolyzed in an inert atmosphere. However, the physical and chemical reactions that occur during pyrolysis of wood are affected by the interaction of the polymers in whole wood as well as the oxygen present in the atmosphere. X-ray photoelectron spectroscopy (XPS) is a surface measurement technique that yields information on both the chemical composition of the sample and the chemical bonds among the elements and compounds that comprise it. Here, XPS was used as a tool to examine the number and type of carbon bonds in Douglas fir exposed to flaming combustion.

 

Predicting the charring rates of timber under non-standard fire exposures

Franz Richter1,3, Panos Kotsovinos2, Guillermo Rein1
1 Department of Mechanical Engineering, Imperial London Collage, UK
2 Arup, UK
3 Department of Mechanical Engineering, University of California, Berkeley, USA

Abstract. Cross Laminated Timber (CLT) is an emerging and promising construction material for high-rise buildings. It is strong, sustainable, and cost-efficient. However, the fire performance of timber remains a concern. Previous work on the fire performance of timber has been experimental and focussed on one single and uniform heating exposure—the standard fire in a furnace. This experimental approach only provides limited insight into the fire performance of timber as neither the furnace nor the standard fire is representative of most real fire conditions. There is a wish to develop a general model of charring to predict the strength decay of timber under real fire exposures. Here, we summarize current work at Imperial College London, which shows for the first time that charring controls the fire performance of timber. Charring itself is controlled by both chemistry and heat transfer, but previous models have neglected the chemistry. Our approach was to develop a novel chemical model of charring of appropriate complexity at the microscale (mg-samples). We then implemented this chemical model into a heat and mass transfer model at the mesoscale (g-samples) and compared the performance of the model against a range of experiments and other computational models from the literature. The combined model was then up-scaled to the macroscale (kg-ton samples) to predict the charring rate of timber elements under various fire exposures: standard fire (small size compartments), parametric fires (intermediate size compartments), and travelling fires (large compartments). We found that charring rates under different fire exposures differ significantly and that design guidance (Eurocode) based on the standard fire is not always conservative for other fire exposures. Together with Arup, we are currently creating a toolkit for fire engineers to improve the design and safety of future timber buildings. 

Odor and FT-IR Analysis of Chemical Species from Wood Materials in Pre-combustion Condition

Kyoko Kamiya and Osami Sugawa
Suwa University of Science, Nagano Prefecture, Japan

Abstract. Not only are signals about smoke and temperature rise, given by fire, but there is also a burnt smell characteristic of fire. Focusing on the odor quality changing, it was applied to fire detection in the early stages. In order to clarify the relationship between changes in odor quality and temperature during oxidation pyrolysis and pyrolysis, the generated odor gas is collected in a sampling bag attached to the exhaust port of the TG-DTA/FT-IR system. FT-IR was used to measure pyrolysis and combustion gases to determine chemical species based on temperature rise rate. The overall odor of the molecules generated by pyrolysis and oxidative pyrolysis in the collected gas every 300 s was then measured using electronic noses. The representation test sample was Japanese cedar. For TG-DTA, the oxygen concentration was set to 0–20% and the temperature rise rate was set to 2–20 K/min. The FT-IR results for the aldehyde group showed a lower temperature at which the absorption peaked than that by the CO. As a result of comparison between odor changes and chemical species during fire combustion, the similarity index of aldehyde groups to the odor at the time of initial fire increased by oxidative pyrolysis. From these facts, in wood and related material it was found that detection of substances based on aldehyde groups among odors generated during pyrolysis and/or combustion can be used as a possibility of fire detection for wooden materials.

 

Effect of Thermal Load on the Heat Release Rate of the Selected Types of Wooden Floorings

Linda Makovicka Osvaldova and Michaela Horvathova
Faculty of Safety Engineering, Department of Fire Engineering, University of Zilina, Zilina, Slovakia

Abstract. The main topic of the article is the effect of thermal load on the heat release rate of the selected types of wooden floors. The article describes three types of fruit trees used for making floor - cherry, apple and plum tree. To obtain necessary information, cone calorimeter, which is described in the article in detail, was used for the experiment. The main quantity observed was the heat release rate (HRR - Heat Release Rate) depending on time. Six samples having the size of 100 100 10 mm were used for the experiment. Three types of wood samples were subjected to thermal load of 40 kW/m2 and the other three to the load of 60 kW/m2 . Practical part focuses on the summary of individual measurement in the cone calorimeter. The description of all three types of wood is shown in tables showing the resulting values. In addition, a graphic representation of the dependence of HRR and time is included as well. On the basis of this, a comparison is carried out. Our goal was to find out the differences between the two levels of thermal load and, at the same time, to compare the wooden floors according to their flammability level based on HRR.

 

Computational study of wood flammability in the context of timber façades

Poppy Fryer, Franz Richter1,2, Guillermo Rein1
1 Department of Mechanical Engineering, Imperial London Collage, UK
2 Department of Mechanical Engineering, University of California, Berkeley, USA

Abstract. Timber is becoming an increasingly popular material choice for creating beautiful and sustainable building façades. However, using timber poses a fire safety risk which must be considered. There has been little research conducted into timber façade flammability, which provided motivation for this study. This study involved developing an existing timber pyrolysis model within ‘Gpyro’, a computational pyrolysis modelling software, to conduct simulations of timber façade panels in a cone calorimeter setup. Sensitivity analysis allowed determination of the material properties which are the most sensitive to the time to ignition. The most sensitive properties were identified as emissivity, followed by density and specific heat capacity. Increasing the density and specific heat capacity and reducing the emissivity retarded the time to ignition. Methods of flammability reduction by modifying the material properties were investigated, the most promising being the use of low-emissivity surface coatings, which were shown to increase the ignition time by 300% for a decrease in emissivity of only 40%. Simulations on the novel 'Superwood' also showed a significant increase in the ignition times, though it is recommended that the application is explored further for wooden structural members such as beams due to the outstanding material properties of Superwood.

 

Experimental Study on Odor from Combustible Wood Materials in Their Pre-fire Situation in House

Osami Sugawa and Kyoko Kamiya
Suwa University of Science, Chino-shi, Nagano Prefecture, Japan

Abstract. Various burning odors are signs of early fire and are perceived as fire by residents. Electronic noses were used to determine the odor qualitative changes during pyrolysis and oxidative pyrolysis of various combustible materials to clarify the possibility of fire detection using odor. The odor generated during combustion depends on the type of flammable substance in the house, so wood and plastic materials were targeted for flammable materials. The precursors of odor during the beginning of pyrolysis and oxidative pyrolysis of house materials and also odor gas during the active period of those were defined as the standard odor gases, respectively. Using these odor gases as respective reference gases, it was used for proper selection and detection of odor fire gas generated during a model fire. These standard odor gases were then used as the fire test reference gas for the two-story model house fire test. Three types of model fire sources, a fast-growing fire, a plastic trash bin fire with wastepaper, and a wood crib fire with towels, were used as model fire sources. Comparison of the output from the fire detector already available with the measured odor change showed that the odor change was detected simultaneously with or immediately after the normal fire detector with a rapidly spreading fire. This situation was obtained because the fire sensor and odor sensor were in the same fire room. The change in odor on the second floor showed a sign of fire about 30 s before the fire was detected by the smoke and temperature rise type detector. When residual odors were present in the room, by making this odor level the reference level, it was possible to prevent false detection of fires by the odor sensor system.

 

The Impact of Radiant Heat on the Flexural Strength and Impact Strength in Spruce Wood Bending

Anton Osvald1 and Jaroslava Štefková2
1 Zvolen, Slovakia
2 The Institute of Foreign Languages, Technical University in Zvolen,Zvolen, Slovakia

Abstract. Thermal degradation influences the wood in a complex way; i.e. it causes the alteration of its properties (weight, volume, shape, and color), as well as the changes of mechanical properties. The main aim of this work is to compare the changes of selected mechanical properties in dependence on the detected weight loss and compare the size of the radiation source. The aim of the research was to examine the changes of strength in bending and impact strength in bending of spruce wood under the influence of radiant heat of S1 source with 1000 W and S2 source of 2000 W outputs. The position of the sample towards the heat source was also observed, in particular, in 50 mm, 100 mm and 150 mm distance. The mass loss measured as the difference of weights before and after the test expressed in per cents was an additional evaluation criterion. The results confirm that the radiant heat, as well as the distance, have an influence on the measured parameters.

 

Anatomical and biochemical changes of thermally modificated hornbeam wood

Horbachova Oleksandra, Mazurchuk Serhii
National university of life and environmental sciences of Ukraine

Abstract. Results of experimental studies of color settings determine and pentosan content in wood hornbeam after thermal modification different modes are shown. It was determined that the achievement of the darkest color of heat treated hornbeam wood corresponds to the degree of pentosan degradation. The results of wood anatomical structure change study due to the high temperatures effect are presented. As samples, was used heat-treated hornbeam wood at temperatures of 160, 190 and 220 °C for 1, 10 and 20 hours. The diameter of pores in the cell walls of the vessels and fibrous elements increases in the hornbeam wood treated at a temperature of 160 °C for 20 hours also the thickness of the cell walls were decreased slightly. When the treatment temperature is increased to 190 °C, significant and irreversible changes occur in the tissues and at 220 °C were discovered complete or partial charring of the organics of the cells of the core rays.

 


 

Wood Burning Retardation and Wood-Based Materials

Fire Retardancy and Leaching Resistance of Pine Wood Impregnated with Melamine Formaldehyde Resin in-Situ with Guanyl-Urea Phosphate/Boric Acid

Chia-feng Lin1, Olov Karlsson1, GeorgeI. Mantanis2, Dennis Jones1, and Dick Sandberg1
1 Wood Science and Engineering, Luleå University of Technology, Luleå, Sweden
2 Lab of Wood Science and Technology, University of Thessaly, Karditsa, Greece

Abstract. This work aimed at finding ways to improve the leaching resistance of Scots pine (Pinus sylvestris L.) wood impregnated with water soluble fire retardant (FR). Sapwood specimens of Scots pine (10 10 50 mm) were impregnated with aqueous solution of guanyl-urea phosphate (GUP)/boric acid (BA). Limiting oxygen index (LOI) revealed that treatment could improve the fire performance. At the same time, thermogravimetric analysis (TGA) illustrated increased thermal stability after the treatment. However, since the FR itself was not fixed within the wood cell wall, it was extracted during water leaching (EN 84), and the wood lost its fire retarding property. The resistance to leaching of FR from the treated wood can be primarily improved while maintaining high fire retarding performance and thermal stability of treated wood by mixing melamine-formaldehyde (MF) resin with GUP/BA before impregnation to the wood. To mix GUP/BA to MF solution, due to the acidic nature of GUP/BA, the condensation/polymerisation reaction would be accelerated in an undesired way even if the solution was adjusted to non-acidic by NaOH. The resulting solution would not penetrate deeply into the wood structure, whilst it would be difficult to re-use the FR solution. In order to avoid the reaction proceeding in an undesired way, introducing 0.5 wt% of pentaerythritol to the GUP/BA/MF solution can decrease the reaction rate. Additionally, it improved the weight percentage gain (WPG) and fire retarding performance, without significantly influencing the leaching resistance and thermal stability. Overall, it is suggested that such a treatment could be a suitable methodology for producing exterior-use fire-retardant pine wood.

 

Application of a Bio-Based Coating for Wood as a Construction Material: Fire Retardancy and Impact on Performance Characteristics

Stephanie Rensink1, Michael F. Sailer1, Roy J. H. Bulthuis2, and Mieke A. R. Oostra3
1 Chair Sustainable Building Technology & Material, Saxion University of Applied Sciences, The Netherlands
2 Chair Nanobio, Saxion University of Applied Sciences, The Netherlands
3 Centre of Expertise Smart Sustainable Cities, Utrecht University of Applied Sciences, The Netherlands

Abstract. The use of living micro-organisms as a protection method on surfaces of wooden building components becomes more common. Since wood is one of the relevant building materials to be used in a circular economy, fire safety and environmental issues are relevant aspects. Up to now, there is little experience in their potential contribution to fire-retardancy. This research aimed to get more information of a wood treatment with a so-called biofinish in combination with an ammonium phosphate based fire retardant. This biofinish system is comprised of a linseed oil impregnation and a protective and decorative coating based on the yeast-like fungus Aureobasidium. Initial tests of wood treated with this biofinish and an ammonium phosphate based fire retardant showed positive effects on the fire growth rate index (FIGRA) and the heat release rate (HRR) in an European fire classification as well as in thermogravimetric analysis (TGA) assessments . This is remarkable since linseed-oil is part of the coating formulation and used by the fungus as a nutrient. The behavior of samples treated with an ammonium phosphate based fire retardant and the biofinish was further studied in an one-year exposure test. This test revealed the potential esthetical stability of such a coating. The study resulted in crack formation and leaching of samples treated with ammonium phosphate and biofinish and stood in contrast with the behavior of wood samples treated with biofinish without an ammonium phosphate treatment.

 

Fire Tests of CLT Specimen Protected by Intumescent Paint

Lars Sørensen and Frank Markert
Department of Civil Engineering, Technical University of Denmark (DTU), Denmark

Abstract. Fire tests of CLT specimen protected by water based intumescent paint designed for wood are conducted at DTU FireLab. The tested CLT was 40 mm thick of dimension 250 250 mm. The intumescent paint is applied in one to four layers given different layer thicknesses on the specimen. Additionally, a protecting topcoat layer is added for half of the tests as it is recommended by the manufacturer to protect the coating from water and weather conditions. The treated specimen are exposed to different heat radiations in a H-TRIS experimental setup, which originally was build to mimic furnace tests, but also has been applied to coating systems [1, 2]. The time to ignition and the charring rate inside the CLT was determined by thermocouples using the 300°C temperature criterion for the on-set of wood charring. The results were compared to literature values. It was found that the observed average charring rate was about 1 mm/min comparable to similar literature values for CLT, but larger than the recommended charring rate of 0.63 mm/min indicated in the Eurocodes. It is found that intumescent paint coatings applied on wood provides passive fire protection to CLT, and the coatings ability to decrease the pyrolysis rate substantially. Furthermore, the time to ignition of the wood is increased. It is found that the protecting topcoat has some influence on the performance of the intumescent coatings. The experiments described here have been conducted by J. A. Wolters as part of his Master thesis on Experimental Analysis of Fire Properties using H-TRIS and PTHFM, January 2020, Technical University of Denmark. His work is greatly acknowledged.

 

Fire Behavior of Bamboo, Guadua angustifolia

Laia Haurie, Alina Avellaneda, and Joaquin Monton
Barcelona School of Building Construction, Universitat Politecnica de Catalunya, BarcelonaTech (UPC), Spain

Abstract. Bamboo is a promising building material because it is a renewable resource and it grows extremely fast. Bamboo has been widely used in the traditional architecture of some countries, but now the development of different bamboo products can expand its applications. As in the case of timber products, one of the main concerns about bamboo is the fire behavior. Therefore, in this work we have studied the fire behavior of the Guadua angustifolia depending on various parameters. We have evaluated the effect of moisture and also the influence of the microstructure on the flammability of bamboo. The results show a clear influence of the level of moisture on the fire behavior and some differences depending on the microstructure of bamboo. The internal part, which is rich in vascular cells and parenchyma tissue, has less ability to form a charred residue than the external layer rich in silicon. Another part of this work consisted on evaluating the performance of different flame retardants added into bamboo trough impregnation. We have used different combinations of flame retardants, based on boron and phosphorous salts. We have found promising results that could allow the improvement of the fire reaction classification of some bamboo products.

 

New Type Fire-Retardant for Various Wood Products

Jussi Ruponen1,2 and Jari Kukkonen1,2
1 Palonot Oy, Espoo, Finland
2 Department of Bioproducts and Systems, Aalto University, Espoo, Finland

Abstract. A novel fire retardant Palonot F1, launched by Palonot Oy, approaches fire retardation with chemistry different from the conventional solutions. The patented technology of Palonot F1 bases on ionic liquid (ILs), and it provides substantial fire safety, the most powerful within the market, and on a remarkably low price compared to established fire-retardant technologies. One key feature of the product is that it neither solidifies nor reaches a crystalline structure. The product itself is sustainable, safe and non-corrosive fireretardant solution and contains no substances of very high concern. Palonot F1 can be applied for various wood products. One of the most simple application technology of Palonot F1 is the post-manufacture surface treatment of plywood. The recommendation is to apply spraying or roller spreader technology for freshly sanded plywood maximum 16 h from hot pressing. Both sides of the panel can be surface treated simoultaneously, and the panels should be stacked directly in order to avoid any drying before stacking. The penetration of the chemical continues within the stack. This way, the highest Euroclass B-s1, d0 fire retardancy is reached and the end products will fulfil the criteria of EN 16755, class DRF INT2. For particleboard production, Palonot F1 should be mixed to surface layer chips either before or after drying of the chips. The core layer chips should be ordinary, non-treated chips for a cost efficient B-s1, d0 process. For MDF process, the pipeline should have an injection possibility for a thorough spreading before the fibre flow has dried too much. Regarding structural products, especially LVL or CLT the recommendation is to complete either immersion or pressure treatment for the veneers or boards. If the treatment is completed in green condition, the spreading of the chemical will be more controlled and more evenly distributed. The even distribution of the ionic-liquid based solution guarantees the powerful performance in the case of fire, leading to extremely low retention levels compared to that of the industry is used to. Finally, according to the our studies for load-bearing structures, the results indicate that Palonot F1 significantly reduces the charring rate of LVL in comparison to the non-treated LVL reference material – by ca. 39%. Therefore, our technology would enable reaching possibly REI 100 with the dimensions that currently are classified to REI 60.

 

The Study of Various Factors Influencing the Fire Retardant Efficiency of Wood Varnish

Tatyana Eremina1, Irina Kuznetsova2, and Lyubov Rodionova2
1 “National Research Moscow State University of Civil Engineering” (MGSU), Moscow, Russia
2 International Scientific Innovative Center of Construction and Fire Safety Ltd., Saint Petersburg, Russia

Abstract. The problem of fire safety of wooden structures is considered. The method of protection of wood materials with fire protection varnish is given. Antipyrene and its quantity were selected to ensure Group I fire protection efficiency. The properties of the acrylic binder and the possibility of its use in the formulation of fire protection varnish are considered and analyzed. Complex tests for the time of independent attenuation of the samples of Group I fire retardant efficiency and fire propagation with a brief description of the methods are carried out. Accelerated climatic and full-scale tests of the fire protection varnish samples were carried out and the service life of the coating was determined to be 10 years. Additionally, in order to confirm the declared operating conditions, the fire protection efficiency of “Intol” fire protection varnish samples was tested. Conclusions were made that the selection of the optimal ratio of components and the study of the influence of various factors on the fire retardant efficiency of the wood varnish allow increasing the fire safety of facilities.

 

Research of Effectiveness of Wood Fire Protection by Modified Epoxy Polymers

Oleksandr Hryhorenko1, Nataliia Saienko2, Volodymyr Lypovyi1, and Serhii Harbuz1
1 National University of Civil Defence of Ukraine, Ukraine
2 Kharkiv National University of Construction and Architecture, Ukraine

Abstract. Providing of fire protection for wood using modified epoxy compositions today is a prospective area of research. Modification of epoxy polymers is achieved by the introduction of fire retardants, dispersed mineral fillers and additives that regulate the properties of materials. The analysis of these components effect on the flammability of epoxy polymers, their flame-retardant, technological and operational properties is an important scientific and practical task. As research objects, compositions based on epoxy oligomer ED-20, hardened with an amine-type hardening agent, were used. To regulate the flammability and operating abilities of epoxy polymers, flame retardants, dispersed mineral fillers and additives, which differed by the nature of oxides, their quantitative ratio and by the particles shape, were used. To determine the flammability of the researched samples, was used the oxygen index method. The effectiveness of the flame-retardant effect of the developed material as wood coatings was determined by the method of weight loss. As a result of the research, it was established that improvement of the flameretardant properties of epoxy polymers is associated with an increasing of their self-ignition temperature and depends from the properties of used additives. The effectiveness of the used additives of metal oxides of transient valence increases with decreasing basicity of these oxides. As a result of the research, it was established that, according to the effectiveness of fire protection, the developed fire retardant coating corresponds to the I group of fire retardant efficiency for wood, and the weight loss of the test samples is on average 2.21%.

 

The Study of the Complex of Properties of Water-Dispersion Fire Retardant Paint for Wooden Structures

Tatyana Eremina1, Dmitry Korolchenko2, and Irina Kuznetsova3
1 “National Research Moscow State University of Civil Engineering” (MGSU), Moscow, Russia
2 Institute of Integrated Safety in Construction of the Federal State Budgetary Educational Institution of Higher Education, National Research Moscow State University of Civil Engineering (MGSU), Moscow, Russia
3 International Scientific Innovative Center of Construction and Fire Safety Ltd., Saint Petersburg, Russia

Abstract. The problem of ensuring fire safety of facilities with wooden structures is discussed. The method of protection of structures made of wood with fire-retardant intumescent paints and its advantages are considered. The complex of properties of fire protection paint of intumescent Therma type is considered and analyzed. The results of complex thermophysical tests of Therma paint for such parameters as expansion ratio, group of fire retardant efficiency and brief descriptions of methods are given. An important parameter in assessing the quality of fire retardant materials is singled out, namely the fire retardant efficiency over time (throughout the entire period of operation). The method of testing the Therma paint for accelerated aging is considered. The results of testing the paint for fire retardant efficiency after accelerated aging are given. In addition, to confirm the declared operating conditions, the research was conducted to study the fire retardant efficiency of the Therma paint samples after the static water resistance tests, and the test results are given. In order to obtain more complete information about the fire protection properties of the Therma paint, a complex thermal analysis was carried out, the thermoanalytical curves and their description were given. Conclusions about the necessity of constant improvement of complex research of Fire protection paints for wood structures in various fields of application are made.

 


 

Fire Modeling, Fire Testing, Fire Certification, Fire Investigation, Fire Dynamic, Fire Behaviour Modelling, Smoke Control and Combustion Toxicity

 

Thermography of Wood-Base Panels During Fire Tests in Laboratory and Field Conditions

Denis Kasymov1,2, Mikhail Agafontsev1,2, Pavel Martynov1,2, Vladislav Perminov1, Vladimir Reyno2, and Egor Golubnichiy1
1 Tomsk State University, Russia
2 V. E. Zuev Institute of Atmospheric Optics SB RAS, Russia

Abstract. The paper represents the experimental study of combustion over the surface of a vertically-mounted oriented wood-based panels (plywood, chipboard and oriented strand board) under different environmental conditions. The IR thermography was used as a diagnostic method. An infrared camera JADE J530SB was used to obtain the sequences of thermograms characterizing the heat flow pattern on the surface of the sample during vertical combustion and determine the velocity of the combustion wave under laboratory and field conditions. In addition, during the field tests the change in the angle of the combustion front was estimated depending on time.

 

Comparison of Cone Calorimetry and FDS Model of Low-Density Fiberboard Pyrolysis

Juraj Jancík1, Paulína Magdolenová1, and Frank Markert2
1 University of Zilina, Slovakia
2 Technical University of Denmark, Denmark

Abstract. Combining bench scale physical experiments with numerical simulations become more and more common to enable upscaling to large scale conditions. Bench scale experiments are easier to control and to reproduce. They are less demanding in time and costs. However, it is essential to verify these simulations during their development process with real tests because incorporating all the factors that affect the burning process into numerical calculations is very challenging and doesn’t necessarily have to correspond to reality. The aim of the paper is to compare time to ignition of the FDS model with a real benchscale experiment. Low-density fibreboards, commonly used for thermal insulation of buildings, are tested. Cone calorimetry is conducted to estimate time to ignition of the fibreboard specimens, which will provide a baseline for further accuracy assessment of the FDS simulation. A simultaneous thermal analysis of wood fibres is carried out to provide input data for the model. Plausible results accuracy would enable application of the obtained outcomes in large-scale FDS enclosure fire simulation.

 

Charring of Timber with Fissures in Experimental and Numerical Simulations

Jaroslav Sandanus1, Zuzana Kamenická2, Peter Rantuch3, Jozef Martinka3, and Karol Balog3
1 Faculty of Civil Engineering, Department of Steel and Timber Structures, Slovak University of Technology in Bratislava, Slovakia
2 Distler Engineering, Slovakia
3 Faculty of Materials Science and Technology in Trnava, Institute of Integrated Safety, Slovak University of Technology in Bratislava, Slovakia

Abstract. Drying fissures occur in some timber structures what can lead to an issue for a mechanical resistance of these structures. There is no proposal to quantify the effect of various fissures and gaps on the charring of timber structural members. Therefore, this contribution deals with the numerical and experimental analysis of selected dimensions and number of fissures. The numerical analysis was conducted in a software based on FEM. There were created models with local fissures and simplified “smeared” models. The samples were tested in a cone calorimeter. There were two types of samples. The charring depth was measured from a split cross-section for the first group of samples. Temperatures were measured by means of thermocouples for the second group of samples and the charring depth was calculated based on these temperatures. The aim of this paper is to compare values of the charring rate and depth for the samples with different fissures. In terms of results, the bigger fissures or larger quantity of fissures should be considered by means of advanced design methods, or by increased value of the charring rate. However, the smaller fissures can be neglected.

 

A Parametric Study of Numerical Modelling of Water Mist Systems in Protection of Wood Frame Buildings

Nour Elsagan and Yoon Ko
Fire Safety Unit, Construction Research Center, National Research Council of Canada, Ottawa, Canada

Abstract. Water mist systems are considered for the protection of timber buildings because they use significantly less water and consequently less postsuppression water damage. Water mist systems are widely used in the fire protection of electronic equipment and machinery rooms in ships and industrial buildings. However, the use of water mist systems in the protection of residential and office buildings is still limited due to the lack of data on their performance in such buildings. As such, there is a research gap that warrants the work of this paper. In this article, numerical modelling of water mist systems in the protection of mass timber buildings was conducted using Fire Dynamics Simulators (FDS). The water mist system was modelled to suppress a fire within a compartment and an open space. Different fuel parameters were investigated; the droplet size of the mist and different finishing (exposed and gypsum-board protected walls and ceiling) of the compartment.

 

Evaluation of Structural Elements Affected by Fire

Jan Bujnak1 and Abdelhamid Bouchair2
1 University of Zilina, Slovakia
2 Université Clermont Auvergne, Institut Pascal, France

Abstract. Fire poses a serious threat to living creatures and to the environment. Presently, numerical and experimental investigations have provided calculation rules for the assessment of the carrying capacity of building components in the event of a fire. Actually, the remaining resistance of structure, depending on time exposure to fire can be evaluated using the current geometry, material and section design characteristic as well as information on fire development provided by fire-fighting crew. Beside the load bearing functions, the separation or insulation criterions could be important. The paper deals with the above mentioned passive fire measurements. Particular emphases are placed on damage assessments and suitability of structure affected by a fire, illustrated on the case study.

 

Feasibility Study of Correlating Mass Quantity Output and Fuel Parameter Input of Different Simulations Using Fire Dynamics Simulator

Steffen Oliver Sæle
Rambøll Norge, Norway

Abstract. While fire dynamics can rarely be calculated more precisely than by use of Computational Fluid Dynamics (CFD), using such techniques in computer simulations are often highly computationally expensive. To possibly reduce computational costs in Fire Safety Design (FSD) where several simulations need to be conducted, the author has investigated the feasibility of correlating variations in mass concentration output of Fire Dynamics Simulator (FDS) to variations in fuel parameter input. In this study, such a correlation is deduced based on the relative significance of the mass source term of the FDS mass transport equation. From the results of 15 conducted simulations, the study suggests that the correlations may be applied to produce reasonable estimations of mass concentration output of a simulated scenario, based on the equivalent results of a base simulation. As such, consequences of fires as a function of fuel properties may be assessed rapidly, compared to conducting multitudes of simulations.

 

Behaviour of Wooden Materials Exposed to Electrical Ignition Sources

Miroslava Nejtková
Ministry of the Interior – Directorate General Fire Rescue Service Czech Republic, Population Protection Institute, Czech Republic

Abstract. This paper deals with fires caused by electrical conductors placed on or near flammable materials. Our homes and accommodation facilities are equipped with many wooden or wood-based objects and many electrical conductors. This paper deals with ignition of electrical fires caused by electrical installations located in the most commonly used materials such as wood, laminate. The aim is to show how the tested materials behave when exposed to an electrical ignition source. The results of these experiments are particularly useful for fire investigators.

 


Fire Safety in Wooden Objects

 

Issues and Solutions for Compartments with Exposed Structural Mass Timber Elements

David Barber1, Robert Dixon2, Susan Deeny3, and Pascal Steenbakkers4
1 Arup, USA
2 Arup, Australia
3 Arup, UK
4 Arup, The Netherlands

Abstract. High-rise mass timber buildings with CLT and glulam are being planned and constructed within the globally. As timber buildings are constructed taller, architects and building owners are requesting more timber be exposed. High-rise buildings are required to have fire resistance ratings for the structural elements that can withstand the design fire in the highly unlikely event of a fully developed fire. Addressing how exposed timber and in particular CLT, influences a fully developed fire through to fire extinguishment is a current fire safety issue. The fire heat release rate and fire duration will be increased due to the added combustible fuel available from the exposed timber, when compared to a compartment without any exposed timber, once all the fixtures and furnishings have been consumed. Existing fire test data shows that large areas of exposed timber has a significant impact on heat release rate, but limited areas of exposed timber can be accommodated within a fire safe design. To design a compartment with exposed timber requires an understanding of the susceptibility of the CLT to char fall off and the expected fire duration due to the area and location of the exposed timber.

 

A Case Study Comparing the Fire Risk in a Building of Non-combustible Frame and a Timber Frame Building

Bjorn Karlsson1, Iris Gudnadottir2, and Bodvar Tomasson1,3
1 University of Iceland, Reykjavik, Iceland
2 Securitas, Reykjavik, Iceland
3 EFLA Consulting Engineers, Reykjavik, Iceland

Abstract. In the last two decades, a considerable number of multi-storey apartment buildings have been constructed in the Nordic countries using timber as load-bearing material. Such constructions have earlier not been allowed by the authorities, mainly due to the fire risk. The Nordic countries there-fore cooperated for some years, within an organisation named Nordic Wood, with the aim of developing construction methodologies that seriously diminish the fire risk in timber-frame multi-storey buildings. Authorities and industry found that it was necessary to develop a new fire risk assessment technique to verify that fire safety can be as high in timber-frame buildings as in other types of buildings, given that the right construction methods be used. Nordic Wood therefore initiated work that led to the development of FRIM-MAB, a Fire Risk Index Method for Multi-storey Apartment Buildings. The method has been described in several reports and papers and was evaluated against a much more elaborate Quantitative Risk Analysis (QRA) method. Both the index method and the quantitative risk analysis were used to rank four different buildings with respect to fire risk and the ranking was identical. The method was then further tested, where 20 timber frame buildings in four Nordic countries were analysed. This work has recently been taken further by comparing the fire risk in a building of a non-combustible frame in 6 storeys and a similar timber frame building. This paper reports on that comparison.

 

Overview of North American CLT Fire Testing and Code Adoption

Samuel L. Zelinka, Laura E. Hasburgh, and Keith J. Bourne
USDA Forest Service Forest Products Laboratory, USA

Abstract. Cross laminated timber (CLT) is becoming more widely available in North America. However, it has not yet achieved widespread use in construction in the United States because provisions for CLT have only recently been added to model building codes. For example, CLT was recognized for the first time in the 2015 International Building Code (IBC), and the 2021 IBC will allow wood buildings made of CLT and other types of mass timber to be constructed up to 18 stories high. The changes to the 2021 IBC were implemented after several years of work from an ICC Ad-Hoc committee on tall wood buildings including fire testing supervised by the US Forest Service, Forest Products Laboratory. The fire tests involved five compartment fire test scenarios on a two-story building and specifically examined occupant egress and firefighter safety in corridors near the compartments. In addition to the fire tests performed by the Forest Products Laboratory, more large-scale fire tests were performed for the revision of the PRG-320 standard; the product standard for CLT in North America. These tests examined the heat resistance of adhesives used in CLT. This paper highlights the important changes to the IBC and the PRG-320 standard as well as summarizes the tests used to validate these changes.

 

From Low-Rise to High-Rise Buildings: Fire Safety of Timber Frame Facades

Anton Kraler, Clemens Le Levé, Thomas Badergruber, and Michael Flach
University of Innsbruck, Austria

Abstract. Timber construction and fire safety are two terms which often lead to discussions, especially if it concerns multi-storey timber buildings. The scientific investigations presented here demonstrate the extent to which the use of a timber façade provides sufficient fire safety for people and the environment. Research work on prefabricated timber frame façade systems is carried out at the Department of Timber Construction at University of Innsbruck. The investigations are performed in three steps. Step 1: Typical fire exposure of buildings, building classes, requirements of high-rise buildings (>22 m fire escape level) and the properties of the materials in question are investigated. Special attention is given to the use of sustainable and ecological materials. Step 2: Performing reaction to fire tests and fire resistance tests with various materials and constructions which are included in classification reports. For this façade system also a connector system and a specific joint design for easy mounting was developed in a PhD thesis. Step 3: This façade element is tested for its suitability for its use in high-rise buildings. In fire tests is shown that the wooden substructure in the façade does not contribute the fire during a certain time. So the ban of inflammable materials in high-rise buildings could be mitigated. The scientific results show that the use of timber in prefabricated façade elements can meet the required criteria.

The protection against charring of timber members provided by insulation materials

Mattia Tiso1,2, and Alar Just1,3
1 Tallinn University of Technology, Estonia
2 Saint-Gobain Isover, Germany
3 RISE Research Institutes of Sweden, Sweden

Abstract. Insulation materials have the potential to alter the fire resistance of timber frame assemblies. At present, Eurocode 5 Part 1-2 provides a model for the fire design of the load-bearing function of timber frame assemblies with cavities that are completely filled with stone wool. The extension of this model for timber frame assemblies with cavities that are filled with glass wool in a post-protection phase was published in the European Technical Guideline, Fire Safety in Timber Buildings. However, very little is known about the form of protection which is afforded by other insulation materials. In order to be able to include the potential fire protection being provided by a wider range of cavity insulation products, a new design approach is proposed in the new revision of the Eurocode 5 Part 1-2 . This design approach comprises a qualification methodology for the insulation materials and an improved design model. The qualification methodology considers the development of the 300°C isotherm on the sides of the timber member is an indicator of the protection being provided by specific forms of cavity insulation against the charring on the timber member. The qualification methodology allows to distinguish three levels of protection for the fire performance of batt-type insulation materials.

 

Fire Performance of CLT Members: A Detailed Review of Experimental Studies Across Multiple Scales

Christos Kontis, Christoforos Tsichlas, Dionysios I. Kolaitis, and Maria A. Founti
Fire Engineering Unit, School of Mechanical Engineering, National Technical University of Athens, Greece

Abstract. Cross-laminated timber (CLT) is an innovative wood product that is increasingly used in both residential and non-residential construction projects, since it offers a range of advantages, such as light carbon footprint, quick erection time, good thermal and sound insulation characteristics. CLT members have the potential to provide excellent fire resistance characteristics, often comparable to typical massive, non-combustible construction assemblies. However, the fire performance of CLT can be affected by a large variety of material and design parameters, such as physical properties (e.g. density, grain orientation), member thickness, number of plies, adhesive type, connector type, protection panels. In this context, this work presents a thorough review of recent experimental studies, aimed at determining the fire behaviour of CLT members. A large number of test results obtained in a broad range of setups, spanning multiple scales, such as cone calorimeter (50 tests), standard fire resistance furnace (90 tests) and fire compartment (20 tests), are comparatively assessed. The impact of the main material and design parameters on several important fire performance factors is investigated. Analysis of the reported experimental results allows the determination of certain global trends that are observed in the majority of cases.

 

Building Envelope Material Solutions for the Timber Structures Intended for Housing and Accommodation in Terms of Fire Safety, Fire Progression, and Consequences of Fire

Agnes Iringová
University of Zilina, Zilina, Slovakia

Abstract. The paper analyses the load-bearing construction systems in timber structures and their application in multi-storey buildings. It deals with the legislative limitations of their use in dependence on the building´s fire height, calculated fire load and the design of fire separating elements. It provides the optimized envelope material solutions in terms of thermal protection considering the sustainable construction according to Europe 2020 Strategy focusing on the use of renewable and recycled materials. Compositions of building envelopes and fire-separating structures are chosen to use in composite or flammable construction systems and apply in model solutions for buildings intended for housing and accommodation. The paper presents statistical data on the occurrence and consequences of fire in the buildings with composite and flammable construction systems compared to the buildings with non-flammable components. The paper also compares the active fire protection in buildings intended for housing and accommodation considering the requirements specified in Slovak and foreign legislation.

 

Fire Design Model for Timber Frame Assemblies with Rectangular and I-Shaped Members

Katrin Nele Mäger1, Mattia Tiso1,2, and Alar Just1,3
1 Tallinn University of Technology, Estonia
2 Saint-Gobain Isover, Germany
3 RISE Research Institutes of Sweden, Sweden

Abstract. Timber frame assemblies (TFA) are load-bearing or separating constructions consisting of timber members, (protective) panelling and void or insulated cavities. The primary protection for a timber member is given by the cladding on the exposed side. After the fall-off of the cladding, insulation materials protecting the sides of timber member might provide the secondary protection. This paper aims to provide an overview of the development of the charring model based on the Effective Cross-Section Method for timber frame assemblies exposed to fire depending on the type of the cavity insulation. The charring model for rectangular and I-shaped timber members is described. The model is based on an extensive fire testing program complemented by thermal simulations. The design model is aimed for the improvement of the revised Eurocode 5 part 1-2 to offer further possibilities for calculations of fire resistance.

 

Behavior of Bamboo Wall Panel at Elevated Temperature

Anu Bala, Ashish Kumar Dash, Supratic Gupta, and Vasant Matsagar
Department of Civil Engineering, Indian Institute of Technology (IIT) Delhi, India

Abstract. With the development of technology, mud plaster has been replaced by cement plaster for supporting bamboo mesh in wall panels and known as ekra wall or bamcrete wall. Usually, low grade mortar is used in making the bamcrete wall, while the latest studies have used high strength mortar. Bamboo burns through pyrolysis process like wood when it is exposed to the fire condition. Fire safety is one of the major challenges for the construction industry to use the bamcrete wall panel. In the present study, performance of bamboo reinforced panels at elevated temperature is presented. Bamboo strips were inter-woven and protected by the cement mortar. The weight-loss and loss of mechanical strength of wall panel has been studied at 100 °C, 200 °C, 300 °C, and 400 °C maintained for a fixed time period.

  

Impact of Bolt Pattern on the Fire Performance of Protected and Unprotected Concealed Timber Connections

Aba Owusu1, Osama (Sam) Salem2, and George Hadjisophocleous1
1 Carleton University, Canada
2 Lakehead University, Canada

Abstract. The fire performance of concealed timber beam connections has been studied over the years, and it has been shown that such connections do not perform as well as exposed and seated connections mainly due to the reduction of the beam’s cross section to accommodate the concealed steel plate. The main objective of the study presented in this paper is to investigate the performance of fully protected and unprotected concealed glued-laminated timber (glulam) beam connections when subjected to fire. For the protected connection configuration, the steel plate and bolts were fully protected from fire using wood strips and plugs, respectively. This research also studied the effect of bolt pattern on the fire performance of concealed glulam connections. Four full-size concealed glulam beam end connections: two protected and two unprotected connections were exposed to CAN/ULC-S101 standard fire, while being loaded to 100% of the ultimate design moment capacity of the weakest connection configuration. In pattern one, two rows of bolts, each of two bolts, were symmetrically positioned near the top and bottom sides of the beam cross section. While, in bolt pattern two, the bottom bolt row was shifted upward to be located at the mid height of the beam section.

 

A Study of the Fire Performance of Timber-Walled Compartments

Avishek Chanda, Swagata Dutta, and Debes Bhattacharyya
Centre for Advanced Composite Materials, Department of Mechanical Engineering, University of Auckland, Auckland, New Zealand

Abstract. The work focuses on the construction of a partial compartment with 3-ply veneer laminates and analysing the fire performance of the laminated natural composite structure. Instead of the typical L-shaped slots, the compartment was built with traditional joints that were constructed using Ados F2, a high-performance general-purpose contact adhesive composed of polychloroprene. The significant aspect of this study is the fire-performance of the sample at a larger scale with certain variabilities from the ASTM E1354 standard, to suit the current requirements. The compartment was constructed with a vertical front wall of size 300 mm x 300 mm and two parallel side walls each having size of 300 mm x 70 mm. The fire performance of the structure was evaluated by performing a modified cone calorimeter test where the cone was held in a vertical position. The tests were conducted under 35, 50 and 69 kW/m2 heat flux values. The results show a comparatively low peak heat release rate, which can be directly attributed to the distance of the burner and the sample, along with significant temperature gradient along the surface of the main wall and an average burn time of 93 s and 84.3 s for 50 and 69 kW/m2 heat flux values, respectively, with no burning experienced for the flux value of 35 kW/m2 . The study indicates that the fire properties of plywood, although having limiting criteria in building structures where fire is a key issue, can be used for benchmarking the future studies to introduce fire safety in plywood structures.

 

Research of Wooden Bearing Structures Behavior Under Fire Condition with Use Advanced Methods of Fire Resistance Calculation Considering Eurocode 5 Recommendation

Serhii Pozdieiev, Stanislav Sidnei, Olha Nekora, and Svitlana Fedchenko
Cherkassy Institute of Fire Safety Named After Chernobyl Heroes of National University of Civil Protection of Ukraine, Ukraine

Abstract. The article contains the research results on the behavior of a slab with a wooden frame in the conditions of exposure to fire with standard temperature regime, using the finite element method in ANSYS APDL software under nonlinear formulation. The recommendations of the second parts of Eurocode 1 and Eurocode 5 were used to set the initial data and the boundary conditions for the corresponding tasks. The calculation data were obtained regarding the temperature distributions in cross section of the slab elements and the data on its stress-strain state. The results of the calculations were compared with the experimental data and their adequacy was established. Based on the conducted researches, the calculation method for fire resistance of timber slabs was developed and tested, according to the calculated data on the stress-strain state of the slab under the influence of fire. The proposed methodology is consistent with the approach to the calculation of fire resistance of wooden building structures using the specified method and contains recommendations on basic assumptions, initial data, parameters of boundary conditions, the choice of models of materials, recommendations for building geometric and grid models, as well as the criteria for reaching the loss of fire resistance state.

 


Forest Fires

 

Experimental Studies of the Localization of Combustion of Forest Fuel Material Using a Water Barrier Line

Geniy V. Kuznetsov, Ivan S. Voitkov, Roman S. Volkov, Yuliana K. Atroshenko, and Pavel A. Strizhak
National Research Tomsk Polytechnic University, Russia

Abstract. The article presents the results of experimental studies of heat transfer in the layers of forest fuel (FF) at localizing the propagating fronts of its flame combustion and thermal decomposition using protective water lines. Such lines were moistened layers of forest fuel before the front of thermal decomposition. The varied parameters were the volume of poured liquid, the size of the barrier line, the conditions of material wetting, specific consumption, irrigation density, etc. The experiments were carried out with typical forest fuels: leaves, needles, and a mixture of leaves and needles. It has been experimentally established that effective conditions of combustion localization may be provided at suppressing the material burning in the vicinity of the water line boundary. The article presents the results of the analysis of the influence of the velocity of the side airflow on the values of the irrigation density required to prevent the combustion front propagation, with and without the use of an earth layer.

 

Numerical Modeling of the Process of Thermal Impact of Wildfires on Buildings Located Near Forests

Valeriy Perminov
Tomsk Polytechnic University, Russia

Abstract. The mathematical modeling of forest fires actions on buildings and structures have been carried out to study the effects of fire intensity and wind speed on possibility of ignition of buildings. The crown forest fire is modeled using physical two-phase model of forest fire proposed by Grishin. The hydrodynamic and thermal interactions between plume, wind flow and building are analyzed. The non-stationary three-dimensional conservation equations for turbulent flow in a multiphase reacting medium that are solved numerically under the input conditions characteristic of a large forest fire. As a result of numerical calculations, the dependences of the distances from the front of the fire to buildings at which the ignition of the latter are possible are obtained.

 

Method for Stand Flammability Classification

Mirosław Kwiatkowski, Ryszard Szczygieł, and Bartłomiej Kołakowski
Forest Research Institute, Poland

Abstract. The fire risk classification now applied in Poland to forest area allows determining fire risk category for the area of Forest District. However, it is impossible to identify the fire risk on the micro scale. The stand flammability classification according to forest habitat types was based on an analysis of fire outbreaks in the period from 2007 to 2017. In elaborating it consideration was given to the number of fires and the burnt area relative to the area occupied by particular forest habitat types and soil cover types. The classification of stands in terms of fire risk shall enable assessing it at the sub-compartment level and to create an Forest Numeric Map layer. In elaborating the final classification method, the weights of individual indices were dependent on the correlation strength of the density of fires or the burnt area and the presence of selected stand types. Taking the above into account, the formula for the cumulative flammability index was derived. The classification of stand flammability according to forest habitat types shall enable the mapping of forests in terms of their fire characteristics at the sub-compartment level. Since a sub-compartment was a basic mapping unit, this led to very detailed, but too fuzzy mapping, which could limit its practical usefulness in certain situations. Therefore, data generalization rules were developed to enable the determination of the flammability class for larger areas, a compartment and a forest range.

 

Hungarian - Slovakian Cooperation Making Aerial Firefighting More Effective: Error Analysis

Agoston Restas
National University of Public Service, Hungary

Abstract. In many cases, suppressing forest fires are very difficult. On the one hand, the location of the fire can be so far from the fire department it takes a long time to reach by ground forces or the place of the fire front can be at such a special place the intervention is impossible to carry out by hand crew. On the other hand, the fire intensity can be so high the protection of the ground forces is not enough to carry out the suppression. In these cases, aerial firefighting can be not just an effective solution to suppress the fire front but even the only way to stop fire. That is also well known, against the effectiveness of the aerial firefighting, this method is a very expensive tool. Using mostly picture analysis, this study focuses on the tactical mistakes of the aerial firefighting to prevent wastes of the process. Summarizing the results, even if the aerial firefighting can be a very effective tool suppressing the fire, in many cases, pilots and managers make not just simply mistakes reducing the potential of the effectiveness of the method but even carry out such maneuvers which are not only ineffective but can cause even dangerous situations. This study based on a Hungarian – Slovakian cooperation during I4F project, which supported by the EU Horizon 2020 program.

 

Vegetation Fire Behavior Prediction in Russia

Aleksandra V. Volokitina1, Tatiana M. Sofronova2 , and Mikhail A. Korets1
1 Sukachev Institute of Forest SB RAS, Russia
2 Astafiev Krasnoyarsk, State Pedagogical University, Russia

Abstract. The systems for vegetation (including forest) fire behavior prediction in the USA and Canada are analyzed. The conclusion is drawn about the complexity of their use in other countries due to natural differences and historically established different approaches to the classification of vegetation. Russia has all the prerequisites to develop a system for fire behavior prediction. Developed are guidelines for improving forest fire danger rating and fire hazard assessment; classification of vegetation fuels and methods of their mapping; a registered software for automatized vegetation fuel mapping; an example of a map for the nature reserve Stolby. A fire spread model is selected based on the availability of the input data. A fire behavior prediction software program is developed to predict spread of tactical fire parts over the area, fire intensity, development of the fire (from the surface fire to the crown or ground one) and immediate fire effects. In addition, the program allows you to calculate the manpower and means for fire suppression. The results of a retrospective software performance test are given on the example of the nature reserve Stolby. The software performance test is planned to be carried out on active fires with the participation of forest fire protection experts.

 

Use of Aviation Technology in Forest Fire Fighting in Slovakia

Kamil Matta
University of Zilina, Slovak Republic

Abstract. The paper deals mainly with the use of aviation technology in forest fire fighting, with a focus on the use of helicopters. Whereas most of forest fires in the past were caused by nature (e.g. lightning), the most common cause today is due to human activity. The number of forest fires nowadays is increasing worldwide due to the worsening global climate situation. Forest Fires themselves are very specific, as these are events in which special technologies need to be used. A large area of Slovakia is covered by forests and forest fires are common there. Particularly the problem is the terrain morphology, which often makes it difficult for fire-fighters to get to the fire site by surface. The use of aviation technology during extinguish a fire is thus often the most effective method. This paper therefore reflects the conditions of using aviation technology during fighting of forest fire in the territory of Slovakia. First part of the paper is focused on forest fire statistics and on the damage caused by forest fires. In the next part, regard is directed to the current conditions of use of helicopters for forest fires, along with their flight times. In the last part of the paper there is a proposal for supplement of the technique in the most endangered areas by forest fires. 


Others Topics Focus on Wood & Fire Safety

 

Fire Protection of Steel Beams by Timber: Thermomechanical Analysis

Antoine Béreyziat1,2, Maxime Audebert1 , Sébastien Durif3, Abdelhamid Bouchaïr3, Amir Si Larbi1, and Dhionis Dhima4
1 University of Lyon, ENISE, France
2 French Environment and Energy Management Agency (ADEME), France
3 Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut Pascal, France
4 Scientific and Technical Center for Building (CSTB), France

Abstract. This study evaluates the possibility to use timber members as a complete or partial fire protection for steel beams. The hybrid elements considered are composed by I or T-shaped steel profiles partially or fully encased into timber members. The thermal behavior is analyzed by using numerical simulation and the fire resistance is calculated by using an analytical method. The thermomechanical behavior of different configurations is compared considering standard fire conditions. This study shows how the wood protection leads to non-uniform thermal conditions into steel profiles for the considered hybrid beams. Therefore, it is proposed to divide steel sections into subsets for a better analysis. This method allows evaluating the mechanical resistance of steel elements during fire, considering a non-uniform temperature distribution. The results indicate that timber protection delays considerably the failure of steel components during fire. The comparison of various configurations shows how fire resistance is improved by using timber-steel beams instead of unprotected steel profiles.

 

Water Mist Systems in Protection of Mass Timber Buildings

Yoon Ko, Max Kinateder, and Nour Elsagan
Fire Safety Unit, Construction Research Center, National Research Council of Canada, Ottawa, Canada

Abstract. Water mist systems are considered for the protection of timber buildings because they use significantly less amounts of water and consequently less post-water damage. Current water mist system standards and testing protocols do not consider fire scenarios involving exposed timber elements, which pose greater fire load and hazards. Therefore, without verifications through fullscale fire tests, these existing standards and test protocols should not be incorporated in the use of water mist systems in protection of timber buildings.

 

Pyrolysis of Wood Biomass to Obtain Biochar and Its Subsequent Application

Petra Roupcova1,2, Karel Klouda1,2, and Simona Slivkova1
1 VŠB-Technical University of Ostrava, Ostrava, Czech Republic
2 Occupational Safety Research Institute, Prague, Czech Republic

Abstract. The contribution characterizes the employed biochar (a product of low temperature pyrolysis of wooden biomass), which has demonstrated excellent sorption effects, by means of examination of its surface (SEM, BET) and by identification of its functional groups and its thermal stability (DSC, TGA). For the purposes of this contribution we modified the input materials (by using joint oxidation with various oxidizing agents and different weight ratios of biochar and graphite). On the contrary, a part of the products was reduced with the objective to obtain a material similar to a graphene molecule via reduced graphene oxide (rGO). The prepared modified samples were further tested to verify adsorption properties of biochar: the tests were performed on samples of wastewater from Slovnaft a.s. (petrochemical industry) and the results were compared with active coal for chromatography, the sorption properties of which are similar to biochar. Sulfur mustard (yperite HD) breakthrough time was also measured for the powder form. Products with a biochar layer between microand nano-textiles in various combinations were tested for permeation of aerosol, paraffin oil and sulfur mustard (yperite).

 

Wood as Fire Protection of Steel in Hybrid Structural Elements

Véronique Saulnier1, Sébastien Durif2, Salah Oulboukhitine1, Abdelhamid Bouchaïr 2, and Gisèle Bihina3
1 Institut Universitaire et Technologique d’Allier, Institut Pascal, France
2 Université Clermont Auvergne, Institut Pascal, France
3 Centre Technique Industriel de la Construction Métallique, France

Abstract. Various solutions are used for steel-timber hybrid elements that associate two timber beams on both sides of a steel plate or a steel profile. Steel is used as mechanical reinforcement to obtain hybrid elements with high performance regarding the strength and the stiffness. Wood is a combustible material but it burns in a controlled way with low thermal conductivity. Steel is non-combustible and shows high performances in normal conditions. However, its mechanical properties decrease dramatically at elevated temperatures. Previous work on wood-steel connections highlighted the wood protection effect enhanced by the migration of water in the wood element and the absorption of some of the fire energy by vaporization of the water contained in wood. The present study focuses on the thermal performances of steel-timber cross-sections to obtain the evolution of temperature on steel element during fire exposure. The aim is to evaluate the wood material as passive fire protection for steel elements in comparison with other common solutions. Experimental program is performed using different types of wood as insulation to protect steel profiles. The thermal gradient is measured in the protected steel section using different pieces of wood in different configurations: partial or full protection with three or four exposure sides of the hybrid cross section. The tests were performed on a furnace prototype developed in the laboratory. The temperatures are measured using type K thermocouples. Results are compared with those given by a finite element model and the analytical expressions of EN1993-1-2.

 

Electric Cables Installed in OSB Boards Surfaces and Their Temperature

Jozef Martinka, Peter Rantuch, Tomáš Štefko, and Igor Wachter
Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Slovakia

Abstract. This paper discusses the impact of low-level electrical current on the temperature of electrical cables installed in surface grooves of oriented strand board (OSB). The three-wire power electrical cable (copper conductors each with a cross-section of 1.50 mm2 ) with fire reaction class B2ca and construction OSB intended for use in dry or humid environments were investigated. The electrical cable was powered by an alternating current (AC) power supply (230 V) and connected to incandescent light bulbs with a total power input of 200, 400 and 600 W (this power input corresponded to an electric currents of 0.87, 1.74 and 2.61 A). Incandescent light bulbs were connected in parallel to the cable. During the test, thermocouples were used to measure temperatures on the surface of the electrical cable, on the surface of the OSB at a distance of 2 cm from the centre of the cable and the ambient temperature. The data obtained show that as the electrical current increases, the temperature of the cable installed in the OSB surface grooves increases. The maximum cable temperature (30.1 °C) was recorded at an incandescent light bulb of 600 W. The recorded temperature (30.1 °C) is lower than the core temperature limit of the investigated cable under normal operation (90 °C).

 

Improvement of Fire Response Efficiency by Means of Reducing the Time of Initial Fire Detection

Yuriy Klyuchka1, Kostiantyn Afanasenko1, and Khalid Hasanov2
1 National University of Civil Defence of Ukraine, Kharkiv, Ukraine
2 Academy of the Ministry of Emergency Situations, Baku, Azerbaijan

Abstract. The paper analyzes the operation of fire emergency response units and auxiliary devices which operate in the infrared range and can be used to extinguish fires. Taking into account the Wien’s displacement law, it is established that in the time interval up to 100 min the maximum emission falls on the wavelength range invisible to the human eye which confirms the practicability of using thermographic cameras in extinguishing fires. In order to determine the fire spread time the time values of fire emergency response unit arrivals to the site of the fire were analyzed. Time values from the moment of fire break-out to the moment of arrival, control and suppression were used as initial data. 50,000 cases of fire have been processed. An expert assessment has been carried out regarding the efficiency of using thermographic cameras during fires. There have been criteria proposed and estimates of the fire response efficiency obtained.

 


 

Poster Abstracts

 

Heat Flux from Wood Filled Transport Package Impact Limiter Under Fire Conditions

Martin Feldkamp, Marina Erenberg, Marko Nehrig, Claus Bletzer, André Musolff, and Frank Wille
Bundesanstalt Für Materialforschung Und - Prüfung (BAM), Germany

Abstract. Packages for the transport of high-level radioactive material must withstand severe hypothetical accidents. Regulatory test conditions shall cover these severe accident conditions and consist of mechanical tests and a following thermal test. To withstand the mechanical tests heavy weight packages are often designed with impact limiters consisting of wood encapsulated in steel sheets. The thermal test is defined precisely in the IAEA-regulations as a 30 min fully engulfing 800°C fire. After the fire phase a pre-damaged impact limiter might continue burning or smouldering and influence the cask thermal behaviour with its energy release. The energy transferred from the impact limiter to the cask is of importance for the safety of transport packages. A full-scale fire test with an impact limiter of 2.3 m in diameter and filled with spruce wood was designed and performed. The impact limiter continued burning for 3 days. Energy transfer and temperature measurements were performed.

 

Reduction of Flammability of Synthetic and Natural Composite Materials Based on Formaldehyde-Containing Bonding Agents

Anatolii Chernov1, Andrey Shmakov1, Oleg Korobeinichev1, Munko Gonchikzhapov1, and Valeriy Tatarenko2
1 Voevodsky Institute of Chemical Kinetics and Combustion, Russia
2 Siberian State University of Geosystems and Technologies, Russia

Abstract. A study has been held to compare flammability of chipboard samples with carbamide formaldehyde or amino formaldehyde resin as binder and with additives of inorganic (ammonium polyphosphate) and organic flame retardants and modifiers (oxidized polysaccharides). To determine the flammability of the chipboard samples under study, the limiting oxygen index method (LOI) was applied. Dependence of the LOI of the chipboard samples produced under laboratory conditions on the concentration of the additives of flame retardants and modifiers has been investigated. The results obtained have shown that introducing into the composition of chipboards raises the LOI to more than 40%, which should significantly improve the FST (Fire, Smoke, Thermal) parameters of the materials of this type.

 

New Method for Mineralization of Wood for Improved Fire Properties

Andreja Pondelak, Rožle Repič, Tomaž Pazlar, Nataša Knez, Friderik Knez, and Andrijana Sever-Škapin
Slovenian National Building and Civil Engineering Institute, Slovenia

Abstract. Wood is an important engineering material due to its remarkable properties. Flammability is one of its main drawbacks, which can be improved by different approaches, like use of fire-retardants. Since some of the fireretardants are at least partially toxic and subject to stringent restrictions, the future lies in use of nontoxic and “eco-friendly” fire-retardants. One of the most promising methods is incorporation of calcium carbonate into the wood’s structure (i.e. mineralized wood). Carbonates have been considered as “green” fire-retardants because they release non-flammable gases such as CO2 and H2O upon endothermic decomposition. The research group from Slovenian National Building and Civil Engineering Institute has proposed a new method for mineralization of wood to improve its resistance to fire which has been recently patented [1]. New method enables us fully effective mineralization of wood, through impregnation with solution of metal acetoacetates which transforms into CaCO3. Incorporation of CaCO3 in the spruce is presented in Fig. 1. Improvement in fire resistance was shown and is presented in the abstract entitled Fire properties of beech wood mineralized by a novel mineralization technique by R. Repič et al. 

 

Influence of the Convection Coefficient for the Modelisation of a Fire Test on a Nuclear Transport Package

Norma Verbrugghe, Gaël Desroches, Marianne Moutarde, and Florence Gauthier
Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-EXP/SSTC, France

Abstract. Nuclear transport packages are used for the protection and transportation of nuclear material by road, train or boat. Therefore, the packages containing the most dangerous materials have to go through many reglementary tests, including a fire test of 30 min at 800 °C. To demonstrate the safety of the package, such a test may be performed on a model of the package, or numerically, with boundary conditions representative of the fire (surface emissivity, environment temperature, convection coefficient…). The guidelines of the regulation give a value of the convection coefficient during the fire, 10 W/m2 /K. Recent research [1] suggests that this value may not be representative of such a fire, and may have to be scaled up. But does a higher convection coefficient necessarily have an impact on the temperatures of the package? In order to answer that question, IRSN has performed calculations on a dummy transport package. This package, 7 m high and a 3 m diameter, is used for the transportation of nuclear materials with a high thermal power. To attest (or contest) the influence of the convection coefficient, this coefficient will take its value within a range from 0 (no convection) to 80 W/m2 /K. The temperature in the package during the fire phase, as well as during the cooling phase which follows the fire, will be observed and the influence of the convection coefficient will be analysed.

 

Study of Selected Fire Characteristics of Beech Wood Depending on Particle Size

Richard Kuracina, Zuzana Szabová, and Karol Balog,
Slovak University of Technology in Bratislava, Slovakia

Abstract. Wood and its processing are associated with significant fire hazards. In the past, there were many significant fires of wood clouds that caused property damage and human lives. The study of flammable wood clouds fire characteristics is the basis for fire and explosion protection. The article deals with the study of the influence of particle size on the ignition temperature of settled and swirled beech wood dust. Measurement of fire characteristics was performed according to EN ISO/IEC 80079-20-2 in GG oven and heated surface. The sample was dust from beech wood with different particle sizes. By measuring, it has been found that with decreasing particle size, the flammability of the samples improves and the minimum ignition temperature (MIT) also decreases.

 

Fire Properties of Beech Wood Mineralized by a Novel Mineralization Technique

Rožle Repič, Andreja Pondelak, Nataša Knez, Friderik Knez, and Andrijana Sever-Škapin
Slovenian National Building and Civil Engineering Institute, Slovenia

Abstract. Wood is one of the most important materials, used in construction. As a material, wood is simple to work with and has good mechanical properties in relation to its mass. However wood is prone to burning, which is its weakness. In this work we present improved fire-resistance of mineralized wood by a new method - impregnation with solution of metal acetoacetate (see abstract entitled New method for mineralization of wood for improved fire properties by Pondelak et al.). We mineralized beech (Fagus sylvatica) wood, the most common Slovenian deciduous tree species. Samples were prepared 100 mm 100 mm 10 mm in size, without visual defects. Samples were vacuum/pressure impregnated with the uptake of dry CaCO3 of 8,8% ± 0,5%. For testing improvement of reaction to fire cone calorimetry (Fire Testing Technology) with 50 kW/m2 of incident heat flux was used. Mineralised wood ignites later in regard to untreated wood and less heat is produced during fire. Smoke emissions are reduced also. Heat release profiles (Fig. 1) shows, that mineralized wood ignites later than untreated. That is due to better thermal conductivity of mineralised wood. Fire growth rate index (FIGRA) is reduced substantially. When burning, CaCO3 releases carbon dioxide (CO2), which cools combustible gases and dilutes them, some water (H2O) is also released, which cools the fuel and combustible gases even more.

 

Analysis of the Existence of Geospatial Data Necessary for Fire Modeling in the Republic of Serbia

Marko Marković, Mirjana Laban, Jovana Maksimović, Tatjana Kuzmić, Mehmed Batilović, and Suzana Draganić
Faculty of Technical Sciences, University of Novi Sad, Republic of Serbia

Abstract. Wildfires have always been a threat to civil security. In some cases, they cannot be prevented. However, if fire modeling was performed in advance using the available software, it can significantly increase the level of safety in the event of their occurrence. In this paper an analysis of the existence of the geospatial data necessary for fire modeling for the selected area in the Autonomous Province of Vojvodina, Republic of Serbia, was performed. In addition to this analysis, it is recorded type of databases, in sense of coverage and data limitations, as well as date range of required data. A software that is used for this purpose, FARSITE, is described: the operating principle and the data necessary for fire modelling fire in it. Based on the research conducted in the paper, it can be concluded at which level the original geospatial data necessary for fire modeling are in the Republic of Serbia and what is necessary to do in order to improve that situation.

 

Comparison of the Effectiveness of Selected Indicators Classifying Burnt Areas on the Basis of Low Altitude Measurements

Anna Szajewska
The Main School of Fire Service, Poland

Abstract. Digital image analysis has played a key role in interpreting spectral images of the ground surface for over 40 years. The physical properties of the material deposited on the surface can be estimated on the basis of reflected radiation with regard to five aspects: the spectral, polarisation, angular, time, and spatial characteristics. Tests of these properties are strongly established in satellite research, which includes remote sensing detection methods used for the classification of forest ecosystems. In terms of fire protection, the important indicators are those which determine the area of the burnt forest or soil cover. The measurements that are useful for applications in fire protection include those which are performed on the site of the event at a low altitude, as they do not impose restrictions on the time of performing the measurement, as is the case with remote sensing detection, and they have no spatial restrictions. This paper presents a comparison of the effectiveness of selected remote sensing detection indicators calculated on the basis of measurements in the visible spectrum and in near infra-red measurements. These ranges can be obtained using a single measurement detector. The example of controlled burning of the soil cover was used to carry out measurements and comparisons of the effectiveness of the indicators calculated on the basis of spectrograms made at a low altitude. The study introduces the terms of ‘false acceptance’ and ‘false rejection’.

 

Influence of high temperature on physical and mechanical properties of hornbeam wood

Mazurchuk Serhii, Horbachova Oleksandra
National university of life and environmental sciences of Ukraine

Abstract. Hornbeam wood is not widely used in woodworking industry at present. Some properties of hornbeam wood as a material for furniture or joinery products can be improved by thermal modification. The influence of thermal treatment on physical (density, colour, moisture absorption and shrinkage), mechanical (compression strength along and across fibres, static bending strength) and technological (impact hardness and wear resistance) properties of hornbeam wood is given. Analysis of physical and mechanical properties of hornbeam wood heat-treated by different schedules allowed to determine optimal parameters of thermal modification: temperature 190 °С and duration 8-12 hours. It was found, that the effect of high temperature is insignificant on the technological properties of hornbeam wood.

Moreover, modified wood is much cheaper and does not require additional surface finishing and impregnation with protective substances and can be used for floor coverings, garden furniture and decor, the arrangement of terraces, playgrounds, etc.

 

Evaluation of the efficiency of manufacturing garden parquet from a thermally modified hornbeam wood

Olena Alekseenko, Oleksandra Horbachova, Serhii Mazurchuk
National university of life and environmental sciences of Ukraine

Abstract. A study of the thermo modified hornbeam wood resistance by different schedules to high environmental humidity was conducted. It has been experimentally established that on the fiftieth day of keeping the samples in a humid environment, the samples of thermomodified hornbeam wood additionally protected with oil-wax showed the best result. They collected the lowest amount of moisture – 3.62%, compared to thermomodified wood under similar conditions (11.73%) and treated azure (3.76%). In untreated wood from this group of samples, this value is 3.4 times higher and is 11.68%. In the conditions of operation in contact with water (water absorption) it was found that the best result in the amount of bulk swelling showed samples treated with azure – 11.85%. If we compare with untreated wood from this group – the value is 2 times higher and is 24.85%. In terms of the amount of water absorbed, the samples treated with azure performed better, gaining 43.40%, slightly worse – treated with oil-wax – 45.99%.

 

Influence of size and temperature on the autoignition characteristics of solid spruce wood

Preimesberger C. 1, 2, * , Rindler A. 1, 2 , Hansmann C.1, 2 , Pfeifer C2 .
1 Competence Centre for Wood Composites and Wood Chemistry, Austria
2 Institute for Chemical and Energy Engineering, University of Natural Resources and Life Science (BOKU), Austria

Abstract. The auto-ignition (without external source) and fire behaviour of wood is very complex and depends on several factors that can influence the ignition behaviour of the material. The influence of size and ambient temperature on the heating and subsequent auto-ignition of spruce wood cubes was studied by conducting experiments in a muffle furnace at five isothermal conditions (240 °C, 270 °C, 300 °C, 330 °C and 360 °C) with four spruce wood cube sizes (5 mm, 10 mm, 15 mm and 20 mm). Temperatures inside the cubes and on the surface were recorded with thermocouples. Additionally, simultaneous thermal analysis (STA) was carried out with milled spruce wood to compare the temperatures measured in the furnace experiments to the temperatures where certain mass losses and exothermal reactions happen in thermogravimetry and differential scanning calorimetry. Results of the furnace experiments show faster heating rates and lower reaction times at higher furnace temperatures. While the samples heat up, isothermal phases at roughly 360 °C can be seen in the temperature recordings. These isothermal phases are thought to be the result of pyrolysis reactions using up all arising energy inside the samples. Only after pyrolyzing most of the cellulose and hemicelluloses, a combination of homogenous oxidation reactions in the gas phase and heterogenous oxidation reactions on the surface lead to ignition and in some cases to complete combustion. The size of the samples is critical in two ways, the amount of volatiles produced and the size of the pyrolyzed surface. The achieved findings contribute to a better understanding of the ignition behaviour of wood and are relevant for future applications especially in the wood building sector.

 

Reaction to fire of solid and laminated wood from Enterolobium cyclocarpum,Tabebuia rosea and Juniperus pyriformis. A comparative study.

Javier Ramón Sotomayor Castellanos
Universidad Michoacana de San Nicolás de Hidalgo Morelia, Mexico

Abstract. The objective of the research was to compare the reaction to fire of specimens of small dimensions of solid wood versus laminated wood. For this, the apparent density of the wood and the time necessary to achieve its ignition were determined experimentally, as well as the loss of mass and its ignition speed, both caused by exposure to fire. These parameters were measured using wood from E. cyclocarpum, T. rosea and J. pyriformis. Thus, special fire reaction tests were carried out with 30 specimens per species and material respectively. The experimental design consisted of tests of normality of the distribution of the samples, tests of equality of standard deviations and their analysis. In addition, linear regressions were determined between the parameters studied and the exposure times. The results allow to conclude: 1. The variable ignition time of solid and/or laminated wood increases proportionally to its apparent density; 2. The loss of mass increases linearly, as the time of exposure to fire increases. The results are specific to this case study, in which, due to its limitations in the experimental protocol, it gives it the character of a comparative study.

 

Technical improvements for the fire, disaster management organisations

Peter Pantya
University of Public Service, Hungary

Abstract. In the field of fire intervention and disaster management, the response organisations has technical equipment needs in very high level. The technical devices are important elements of the successful and as efficient as possible inteventions, fire and technical rescue incidents. There is a direct link between the exact application of the most appropriate technical equipment and the most appropriate for the given damage and the success of the liquidation, including its quality. The quality of the intervention can be seen in the value saved by the response units, the additional loss avoided, the less extent of personal injuries. We can find an overview of the Hungarian and also an international perspective is provided by the fire brigades, the new possibilities, improvements for technical equipment used by the fire organisations.

 

 

fbi 250 150

kpi 250x150

wfs 250x150

Ventures

On-line webinar
2 Nov 2020, 9:00 - 3 Nov 2020, 22:00 (CET)

Wood & Fire Safety, all rights reserved - info@wfs2020.sk - webdesign INTELI.SK