Hygrothermal Material Properties What input data are necessary for WUFI

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Hygrothermal Material Properties What input
data are necessary for WUFI?
Heat
Moisture
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1. Definition of the Assembly in WUFI
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1. Definition of the Assembly in WUFI
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2. Basic Properties

• Three Categories

• Basic Properties
• Approximated Functions
• Enhanced Properties

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2. Basic Properties
Bulk density

• Easy to measure, known for most materials
• High accuracy is not needed
• Required for heat capacity determination

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2. Basic Properties
Porosity

• Needed, when a material can absorb vapor or water
  in its pore structure.

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2. Basic Properties
Porosity
Measurement techniques

• water saturation under pressure
• Helium pychnometry
• mercury intrusion

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2. Basic Properties
Specific Heat Capacities
Measurement technique calorie meter
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2. Basic Properties
Heat Conductivity
Measurement technique Guarded hot plate
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2. Basic Properties
Heat Conductivity
Dependency

• density

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2. Basic Properties
Heat Conductivity

• Dependency
• density

• temperature

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2. Basic Properties
Heat Conductivity

• Dependency
• density

• temperature

• water content

Transient latent heat effects - moisture
movements due to vapor diffusion
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2. Basic Properties
Heat Conductivity

• Dependency
• density

• temperature

• water content

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2. Basic Properties
Heat Conductivity
Dependency

• density

• temperature

• moisture

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2. Basic Properties
Heat Conductivity
Dependency

• density

• temperature

• moisture

• orientation

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2. Basic Properties
Vapour Diffusion Resistance
dry-cup test 0 / 50 RH wet-cup test 50 /
95 RH
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2. Basic Properties
Vapour Diffusion Resistance
Permeance D perm
Permeability perm in
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2. Basic Properties
Vapor Diffusion Resistance
Humidity dependency?
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3. Optional Parameters
Moisture Storage Function

• Water molecules are absorbed on the interior
  surface of the pores

• The amount is a function of RH

• Remarks
• Difference between absorption and desorption
• Small temperature dependency
• Maximum range up to 95 RH

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3. Optional Parameters
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?

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3. Optional Parameters
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?

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3. Optional Parameters
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?

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3. Optional Parameters
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?

Small tubes have a high suction pressure Large
tubes have a high suction speed
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3. Optional Parameters
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?

• What pressure is needed to force water out of a
  material?

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3. Optional Parameters
Moisture Storage Function

• What force is affecting on the water inside the
  porous media?

• What pressure is needed to force water out of a
  material?

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3. Optional Parameters
0.1 bar
Moisture Storage Function

• What force is affecting on the water inside the
  porous media?
• What pressure is needed to force water out of a
  material?

Air pressure
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3. Optional Parameters
0.5 bar
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?
• What pressure is needed to remove water from a
  material?

Air pressure
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3. Optional Parameters
5 bar
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?
• What pressure is needed to remove water from a
  material?

Air pressure
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3. Optional Parameters
50 bar
Moisture Storage Function

• Capillary force is acting on the water inside the
  porous media?
• What pressure is needed to remove water from a
  material?

Air pressure
Pressure must be higher than the capillary
pressure!
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3. Optional Parameters
Moisture Storage Function
Measurement technique pressure plate apparatus
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3. Optional Parameters
Moisture Storage Function
Is there a relationship between relative
humidity and capillary pressure?
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3. Optional Parameters
Moisture Storage Function
Relation can be described by Kelvins law

• Pressure plate measurements are complicated and
  time consuming
• Alternative approximation with material
  properties from sorption tests

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3. Optional Parameters
Moisture Storage Function
Approximation
2 Parametersu80 und u95
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3. Optional Parameters
Capillary transport
Water absorption test
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3. Optional Parameters
Capillary transport
Problem only integral information Influence of
the pore structure ?
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Small tubes have a higher suction
pressure. Large tubes have a higher suction
speed
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Stop of the water supply
Redistribution of the water profiles
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Stop of the water supply
Redistribution of the water profiles
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Stop of the water supply
Redistribution of the water profiles
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Stop of the water supply
Redistribution of the water profiles
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3. Optional Parameters
Capillary transport
Influence of the pore structure
Stop of the water supply
Redistribution of the water profiles
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3. Optional Parameters
Capillary Transport
Measurement of the moisture profiles
Gamma-ray
NMR-Scanner
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3. Optional Parameters
Brick
KU Leuven
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3. Optional Parameters
AAC
KU Leuven
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3. Optional Parameters
Different speed ? 2 different transport
coefficients!
Capillary Transport
Measurement of the moisture profiles
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3. Optional Parameters
Approximation
Capillary Transport
Dw(uf) Liquid transport coefficient at free
saturation Dw(u80) Liquid transport coefficient
at 80
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3. Optional Parameters
Capillary Transport
Approximation
Suction
Liquid transport coefficient at free saturation
depends on

• A-Value
• Capillary saturation
• Moisture content at 80 RH

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3. Optional Parameters
Capillary Transport
Approximation
Drying

• Iterative process
• Determination by drying experiment under defined
  conditions

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3. Optional Parameters
Test of approximation
Water absorption
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3. Optional Parameters
Test of approximation
Exposed sandstone fassades
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4. Summary
Complex material properties can be approximated
with the following values

• density
• porosity
• heat capacity
• heat conductivity
• moisture dependency of the heat conductivity
• sorption moisture content at 80 and 95
  relative air humidity
• free water saturation
• A-value

Good news about 100 materials in WUFI
Database Bad news mostly European materials B U
T ORNL is working hard to provide more data !!!