1. Introduction
Commercial gypsum boards are widely used in the building
industry as facing materials for walls and ceilings due to their very
good mechanical and thermal properties, as well as fire endurance.
The endothermic dehydration process that takes place at high
temperatures is capable of slowing down the fire spread through
gypsum board based systems. From the fire safety point of view,
gypsum dehydration can be of greatimportance, allowing sufficient
building evacuation times.
Several computational efforts have been made in the pastto predict
the thermal behavior of gypsum boards under fire conditions.
They revealed the significance of using appropriate physical properties
for simulating the temperature evolution inside a gypsum
board when exposed to fire conditions [1–6]. Depending on the
composition of the gypsum board, the reactivity of the characteristic
endothermic and/or exothermic reactions may vary. In addition,
the behavior of the material under fire conditions is affected bythe variability of physical properties associated with the different
heating rates.
The aim of this work is to provide a framework that can
facilitate the detailed simulation of the thermal behavior of commercial
gypsum boards exposed to elevated temperatures. For this
purpose, experimental data obtained using Differential Scanning
Calorimetry (DSC) measurements were combined with theoretical
formulations in order to create a set of equations for the definition
of different parameters relating to gypsum board chemical kinetics.
The equations that are presented define the composition of the
gypsum boards, the energy that is absorbed/produced during gypsum
board heating and the reaction kinetics parameters (Arrhenius
parameters and reaction model) for three main reactions: evaporation
of free moisture content, dehydration of chemically bound
water and crystal mesh reorganization.
1. IntroductionCommercial gypsum boards are widely used in the buildingindustry as facing materials for walls and ceilings due to their verygood mechanical and thermal properties, as well as fire endurance.The endothermic dehydration process that takes place at hightemperatures is capable of slowing down the fire spread throughgypsum board based systems. From the fire safety point of view,gypsum dehydration can be of greatimportance, allowing sufficientbuilding evacuation times.Several computational efforts have been made in the pastto predictthe thermal behavior of gypsum boards under fire conditions.They revealed the significance of using appropriate physical propertiesfor simulating the temperature evolution inside a gypsumboard when exposed to fire conditions [1–6]. Depending on thecomposition of the gypsum board, the reactivity of the characteristicendothermic and/or exothermic reactions may vary. In addition,the behavior of the material under fire conditions is affected bythe variability of physical properties associated with the differentheating rates.The aim of this work is to provide a framework that canfacilitate the detailed simulation of the thermal behavior of commercialgypsum boards exposed to elevated temperatures. For thispurpose, experimental data obtained using Differential ScanningCalorimetry (DSC) measurements were combined with theoreticalformulations in order to create a set of equations for the definitionof different parameters relating to gypsum board chemical kinetics.The equations that are presented define the composition of thegypsum boards, the energy that is absorbed/produced during gypsumboard heating and the reaction kinetics parameters (Arrheniusparameters and reaction model) for three main reactions: evaporationof free moisture content, dehydration of chemically boundwater and crystal mesh reorganization.
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