The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)

The paper assesses the influence of the heat flux on spruce wood (<i>Picea abies</i> L.) behavior. The heat flux was performed at 15, 20, 25, and 30 kW·m<sup>−2</sup>. The fire-technical properties, such as the mass burning rate, charring thickness, charring rate, as well as...

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Main Authors: Martin Zachar, Iveta Čabalová, Danica Kačíková, Lucia Zacharová
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/14/17/4989
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author Martin Zachar
Iveta Čabalová
Danica Kačíková
Lucia Zacharová
author_facet Martin Zachar
Iveta Čabalová
Danica Kačíková
Lucia Zacharová
author_sort Martin Zachar
collection DOAJ
description The paper assesses the influence of the heat flux on spruce wood (<i>Picea abies</i> L.) behavior. The heat flux was performed at 15, 20, 25, and 30 kW·m<sup>−2</sup>. The fire-technical properties, such as the mass burning rate, charring thickness, charring rate, as well as the chemical composition (contents of the extractives, lignin, cellulose, holocellulose), of wood were determined. The highest burning rate of spruce wood of 0.32%·s<sup>−1</sup> was reached at the heat flux of 30 kW·m<sup>−2</sup>. The charring rate ranged from 1.004 mm·min<sup>−1</sup> (15 kW·m<sup>−2</sup>) to 2.016 mm·min<sup>−1</sup> (30 kW·m<sup>−2</sup>). The proposed model of the charring process of spruce wood in time and appropriate thickness as a selected parameter is applicable in validation of the results of computer fire models in the design of fire protection of wooden buildings. The decrease in the holocellulose content mostly caused by the degradation of hemicelluloses was observed during thermal loading. The biggest decrease in hemicelluloses (24.94%) was recorded in samples loaded at 30 kW·m<sup>−2</sup>. The contents of cellulose increased due to the structural changes (carbonization and crosslinking), the content of lignin increased as well due to its higher thermal stability compared to saccharides, as well as the resulting lignin condensation.
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spelling doaj.art-930e06ef0888402cb62d8945c52ec83a2023-11-22T10:54:39ZengMDPI AGMaterials1996-19442021-08-011417498910.3390/ma14174989The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)Martin Zachar0Iveta Čabalová1Danica Kačíková2Lucia Zacharová3Department of Fire Protection, Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 01 Zvolen, SlovakiaDepartment of Chemistry and Chemical Technologies, Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 01 Zvolen, SlovakiaDepartment of Fire Protection, Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 01 Zvolen, SlovakiaNational Forest Centre, Forest Research Institute, 960 01 Zvolen, SlovakiaThe paper assesses the influence of the heat flux on spruce wood (<i>Picea abies</i> L.) behavior. The heat flux was performed at 15, 20, 25, and 30 kW·m<sup>−2</sup>. The fire-technical properties, such as the mass burning rate, charring thickness, charring rate, as well as the chemical composition (contents of the extractives, lignin, cellulose, holocellulose), of wood were determined. The highest burning rate of spruce wood of 0.32%·s<sup>−1</sup> was reached at the heat flux of 30 kW·m<sup>−2</sup>. The charring rate ranged from 1.004 mm·min<sup>−1</sup> (15 kW·m<sup>−2</sup>) to 2.016 mm·min<sup>−1</sup> (30 kW·m<sup>−2</sup>). The proposed model of the charring process of spruce wood in time and appropriate thickness as a selected parameter is applicable in validation of the results of computer fire models in the design of fire protection of wooden buildings. The decrease in the holocellulose content mostly caused by the degradation of hemicelluloses was observed during thermal loading. The biggest decrease in hemicelluloses (24.94%) was recorded in samples loaded at 30 kW·m<sup>−2</sup>. The contents of cellulose increased due to the structural changes (carbonization and crosslinking), the content of lignin increased as well due to its higher thermal stability compared to saccharides, as well as the resulting lignin condensation.https://www.mdpi.com/1996-1944/14/17/4989spruce woodheat fluxcharring thicknesscharring ratechemical composition
spellingShingle Martin Zachar
Iveta Čabalová
Danica Kačíková
Lucia Zacharová
The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
Materials
spruce wood
heat flux
charring thickness
charring rate
chemical composition
title The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
title_full The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
title_fullStr The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
title_full_unstemmed The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
title_short The Effect of Heat Flux to the Fire-Technical and Chemical Properties of Spruce Wood (<i>Picea abies</i> L.)
title_sort effect of heat flux to the fire technical and chemical properties of spruce wood i picea abies i l
topic spruce wood
heat flux
charring thickness
charring rate
chemical composition
url https://www.mdpi.com/1996-1944/14/17/4989
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