Hokkaido University
EVDON LUZANO SICAT, M1
Faculty of Engineering
Division of Built Environment
Laboratory of Engineering
for Maintenance System
Clarification of Frost Damage
Mechanism Based on Meso scale
Deformation and Temperature
and Moisture Change
Contents
LOGO
A
BACKGROUND:
FORST DAMAGE MECHANISM
B
RESEARCH OUTLINE
C
EXPERIMENTAL OUTLINE
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Background
LOGO
Freeze-thaw Deterioration
Concrete, like other highly divided porous media, has the
ability to absorb and retain moisture. This characteristic
has an important consequence since unprotected
concrete structures in contact with water are usually
susceptible to frost damage.
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Background
LOGO
Frost Damage Mechanism
Concrete Condition: Unsaturated
•
•
•
The pore structure is filled by small amount of water.
Once temperature drops to 0ºC – Thermal contraction
occurs.
From 0ºC to minimum temperature – Water in larger
pores freezes.
ice
water
•
From freezing temperature to thawing – ice melts and
water flows to pore spaces.
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Background
LOGO
Frost Damage Mechanism
Concrete Condition: Saturation Process
-
Possible only if water is available outside during thawing at
temperature above 0ºC.
When freezing for temperature below 0ºC – water freezes and
volume expands (can create tension to concrete).
At temperature below -10ºC to minimum temperature – ice
contracts in larger pores.
Contracted Ice
water
Increment pore space
-
From minimum temperature to -5ºC during thawing – ice expands
more than surrounding concrete.
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Background
LOGO
Frost Damage Mechanism
Concrete Condition: Saturated Condition
-
In this condition, the pore structure is totally filled by water.
As temperature continues to drop, the expansion of water creates
a very high positive hydraulic pressure.
For lowest temperature – water in smaller pores also freezes.
Larger cracks
Smaller pores
begin to freeze
Ice
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Research Outline
LOGO

Objective:
To clarify the effect of temperature history and
moisture conditions on concrete that are under the
effect freezing and thawing actions.

Previous Model Consideration (Oiwa-san’s Model):
Strains caused by temperature difference and ice
formation.
 T    Td
 i  i  i
Where: εT is linear expansion strain, α is linear
expansion coefficient;10 [/℃], Td is temperature
difference, εi is expansion strain caused by ice formation,
αi is freezing expansion coefficient; 6250 [μ], Ψi is ice
content.
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Research Outline
LOGO
Some considerations:
 Residual strain was not taken into account
during freezing and thawing cycles.
 Specimens are analytical model, for its
viability: results must have a comparison
with experimental data.
 Super cooling and expansion of water when
freezing are not considered.
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Research Outline
LOGO
Model Proposal (Arai-san’s Paper):
The total strain ε for the transformation model of
mortar due to frost damage is assumed to be
composed of three strains which are presented as
follows:
  i   s  t
εi: Expansion strain when freezing
εs: Shrinkage strain when freezing
εt: Temperature strain
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Research Outline
LOGO
 The model of expansion strain when freezing εi is a function of ice
content ratio Ψi. When moisture content ratio is small, the
expansion is not caused.
Then, the following expressions are assumed.
 i   i  i - ic 
αi: Constant of proportion that changes by rigidity of mortar
Ψic: Ice content ratio when transformation began to depend on ice
content ratio
 The shrinkage when freezing is thought to be shrinkage by the
movement of the unfrozen water. It is expressed as follows by
assumption that the transformation depends on the unfrozen rate.
 s   s   - i 
αs: Constant of proportion that shows unfrozen rate contributes to
shrinkage. It changes by the rigidity of mortar.)
ψ: moisture content ratio
 The temperature strain is expressed as follows by linear
coefficient of expansion αt.
 t   t  T
ΔT: Temperature difference
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Experimental Plans
LOGO
Purpose of the Experiment:
 To obtain the following coefficients experimentally;
thermal expansion  t , freezing expansion  i , and
shrinkage contraction  s and then apply them in the
proposed frost damage mechanism model.
 i   i  i - ic  - Freezing strain
 s   s   - i 
- Shrinkage strain
 t   t  T
- Thermal Strain
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Experimental Plans

LOGO
Specimens to be Used
Mortar will be use as test specimen in this experimental
program.
A. Materials Characteristics:
Cement – Ordinary Portland cement (Density: 3.14 g/cm3)
Fine Aggregate (from Mukawa) (Size: 1.2mm and Density:
2.67 g/cm3)
Air-Entraining Agent – None (To Promote Frost Damage)
Table-1 Mix Proportions (Mortar)
Water cement ratio
（％）
Water
（kg/m3）
Cement
（kg/m3）
Fine Aggregate
（kg/m3）
50
244.6
489.2
1467.6
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Experimental Plans

LOGO
Preparation of Specimens
Casting and mold - 40 x 40 x 160 mm form
Curing Period – 60 days (Moist Condition - 23ºC)
Specimen dimension - 40 x 40 x 2 mm
Table -2 (Specimen set and Moisture Conditions)
5 Specimens/Set
Moisture Condition
Purpose
A
Absolutely Dry
Thermal Expansion
B
(Nearly or Fully) Saturated
Freezing Expansion
C
20 - 50% Saturated
Shrinkage Contraction
D
80 –90% Saturated
Comparison to Model’s Output
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Experimental Plans
LOGO
 To attain different kind of moisture conditions on
specimens, they will be subjected in different desiccators
with different kind of salt solution.
Table-3 Salts solutions
Desiccators
Salts
(Potassium Nitrate) KNO3
(Potassium Chloride) KCl
Chloride) NaCl
Graph from AGM Container Controls, Inc. (AGM)
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Experimental Plans
LOGO
Experimental Set-up
Specimens
PC
Temperature increment: 0.5ºC/minute
Data logger
Environmental Chamber
Specimen support
Temperature sensor
Coefficients  t ,  s , and  i can be approximated
by formula of coefficient of linear expansion.
Temperature History Cycle for Set A, B, and C Specimens
L L
  (T  T0 )

LO LO
Temperature History Cycle for Set D Specimens
Clarification of Frost Damage Mechanism based on Mesoscale Deformation and Temperature and Moisture Change
Laboratory of Engineering for
Maintenance System
Hokkaido University
Faculty of Engineering
Division of Built Environment
Laboratory of Engineering
for Maintenance System
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