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((33))Mechanism of deterioration Mechanism of deterioration due to frost damage due to frost damage
and performance predictionand performance predictionand performance predictionand performance prediction
Prof. Yukio HAMAProf. Yukio HAMAProf. Yukio HAMAProf. Yukio HAMA((((MuroranMuroranMuroranMuroran Institute of Technology)Institute of Technology)Institute of Technology)Institute of Technology)
Deterioration assessment of existing structures
Simulation model for durability design
Permeability
Performance prediction system
Mechanism of frost deterioration
Mixture Materials
Neutralization
Evaluation of environmental condition
Weathering condition
Pore structure
PermeabilityMixture Materials
Diagnosis
technique
Equivalent cycles to ASTM C666 A
Temperature Humidity
Frost damage
Evaluation of environmental condition
Moisture in concrete
Deterioration assessment of existing structures
CyASTM-sp = C×F×s×p×Ra90
Cy ASTM-sp: Equivalent cycles to ASTM (cycles/year)C: Coefficient of curing conditionsF: Coefficient of freezing and thawing conditions
Evaluation index of environmental conditions :
[ Equivalent cycles to ASTM ]
F Coefficient of freezing and thawing conditionss: Condition factor of sunshinep: Factor of degradation process
Ra90=∑(-ts/18)β
ts:Minimum freezing temperature β: Constant
Ra90: Equivalent cycles to ASTM by air temperature
Relative dynamic modulus of elasticity(%
)
RaRaRaRa90-AAAA ⇒⇒⇒⇒ RaRaRaRa90-EEEEB sluice:Ra90-A
A sluice:Ra90-A=Ra90-E
A sluice B sluice
Deterioration assessment of existing structures
Yearly number of equivalent cycles to ASTM Ra90
Relative dynamic modulus of elasticity
Ra90-A: Number of equivalent cycles to ASTM by concrete temperature
Ra90-E:Effective number of freeze/thaw cycles
【 Number of equivalent cycles to ASTM over 90%RH】
B sluice:Ra90-E
B :slab
A :slab
B :upper wall
B :lower wall
A :upper wall
Clarification of various deterioration mechanism
Simulation model for durability design
Permeability
Performance prediction system
Mechanism of frost deterioration
Mixture Materials
Neutralization
Mechanism of frost deterioration
Weathering condition
Pore structure
PermeabilityMixture Materials
Diagnosis
technique
Equivalent cycles to ASTM C666 A
Temperature Humidity
Frost damage
Evaluation of environmental condition
Moisture in concrete
Pore structure change by aging and frost resistance
Aging under real environment
Coarsening of pore
structure
Degradation of Frost
resistance
Nano structure of C-S-H before drying
Nano structure of C-S-H after drying
Clarification of various deterioration mechanism
drying
Capillary pore
Drying and Wetting
drying
60
Outline of Experiment
50DWMuroranMuroran TokyoTokyo
<Specimen>
Mortar
Cement : OPC(N), FB, BB
W/B : 0.35, 0.55
Curing : 4 weeks in water, 6 months in water
Drying and wetting : 50DH, 50DL, 50DW, 50W
Exposure : Muroran, Tokyo, Okinawa for 1 year
Clarification of various deterioration mechanism
-10
0
10
20
30
40
50
0 20 40 60 80 100Relative Humidity(%)
Tem
per
atu
re (℃
)
Environmental conditions
50DH50DL50W
4WK
50DW
20W
20D ・6MK
Muroran(M)Tokyo(T)
Okinawa(O)
OkinawaOkinawa
Outdoor exposure test
0.01
0.02
0.03
0.04
0.05
0.06
0.07
Pore volume of 40~~~~2000nm diameter
Drying and wetting curing
Exposure
Ref.
Ref.
~2000nm
(cc/
g)
NW/B=0.35
NW/B=0.55
Exposure
Drying and wetting curing
Clarification of various deterioration mechanism
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0
Ref.
Ref.Pore
volu
me
of
40~
Specimens
FBW/B=0.35
FBW/B=0.55
Exposure
Exposure
Drying and wetting curing
Drying and wetting curing
0.04
0.05
Relationship between pore volume of 40~~~~2000nm
diameter and ink bottle pore volume
BB
Ink
bot
tle
por
e (c
c/g)
N FB
4WK/6MK 室内環境変化養生 屋外暴露Outdoor exposureDrying and wetting
Clarification of various deterioration mechanism
0
0.01
0.02
0.03
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07
Pore volume of 40~2000nm diameter(cc/g)
Ink
bot
tle
por
e (c
c/g)
R=0.833 R=0.894 R=0.826
80
100
120
40
60
80
100
120
Du
rab
ilit
y F
act
or BB
NW/B=0.35
Relationship between pore volume of 40~~~~2000nm
diameter and durability factor ((((N,,,,FB,,,,BB))))
Du
rab
ilit
y F
act
or FBW/B=0.35
Dry/Wet
Dry/Wet
Exposure
Clarification of various deterioration mechanism
0
20
40
60
0 0.02 0.04 0.06 0.08
0
20
Du
rab
ilit
y F
act
or
Pore volume of 40~2000nm(cc/g)
W/B=0.35Air:3.7%
0
20
40
60
80
100
120
0 0.02 0.04 0.06 0.08 0 0.02 0.04 0.06 0.08
Du
rab
ilit
y F
act
orNW/B=0.55Air:1.4%
W/B=0.35Air:2.8%
FBW/B=0.55Air:1.0%
Pore volume of 40~2000nm(cc/g)
Dry/WetDry/Wet
Exposure
Exposure
Exposure
0.02
0.03
0.04
0.05
0.06
0.07
Relationship between temperature
and pore volume of 40~~~~2000nm diameter
NW/B=0.35
2000n
m(c
c/g)
R=0.984
R=0.733
NW/B=0.55
20D-4W 50DH-4W M T O
Clarification of various deterioration mechanism
0
0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 10 20 30 40 50 60 0 10 20 30 40 50 60
Temperature(℃)
Por
e vo
lum
e of
40~
2000n
m
NR=0.984
R=0.925
R=0.971
FBW/B=0.35
FBW/B=0.55
0.02
0.03
0.04
0.05
0.06
0.07
Relationship between relative humidity
and pore volume of 40~~~~2000nm diameter
NW/B=0.35
2000n
m(c
c/g)
R=0.673
R=0.781
NW/B=0.55
50DL-4W 50DH-4W M T O
Clarification of various deterioration mechanism
0
0.01
0.02
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 20 40 60 80 100 0 20 40 60 80 100
Relative Humidity(%RH)
Por
e vo
lum
e of
40~
2000n
m
R=0.673
R=0.821
R=0.580
W/B=0.55
FBW/B=0.35
FBW/B=0.55
Factors effecting on pore structure change by aging
Y = 0.088 Temp.– 0.120 W/B + 1.582 FB – 1.522 BB + 5.749
Here, Y : Pore40-2000 after aging / Pore40-2000 at 4 weeks in water
W/B(%)
FB : cement type ( N=0, FB=1, BB=0)
BB : cement type ( N=0, FB=0, BB=1)
12
Clarification of various deterioration mechanism
-2
0
2
4
6
8
10
12
-2 0 2 4 6 8 10 12
Y :
Calc
ula
ted
valu
e
Y : Experimental value
R=0.85
Simulation model for durability design
Permeability
Performance prediction system
Mechanism of frost deterioration
Mixture Materials
Neutralization
Deterioration assessment of existing structures
Performance prediction system
Weathering condition
Pore structure
PermeabilityMixture Materials
Diagnosis
technique
Equivalent cycles to ASTM C666 A
Temperature Humidity
Frost damage
Evaluation of environmental condition
Moisture in concrete
Relationship between relative dynamic modulus of elasticity
and ratio of carbonation speed
Cr=-0.0145RDM+2.5034 by Matsumura et al.(2003)
(R2=0.61)2.0
2.5 Ratio of carbonation speed
y = -0.0163x + 2.6433R² = 0.8968
0.0
0.5
1.0
1.5
0 20 40 60 80 100
Ratio of carbonation speed
Relative dynamic modulus of elasticity (%)
Assume frost damage
(W/C=0.65、0.75)
Damaged depth
試験体作製 Deterioration assessment of existing structures
Outline of Experiment
base
W/C=0.55
Model specimenDamaged concrete
Carbonation speed
Permeability
Dynamic modulus of elasticity
Silicon plug50mm
10mm
Air permeability test : Figg’s intrusive method
Vinyl tube
Vacuum pump
Deterioration assessment of existing structures
Needle
T>10s: T=Time from P1(25.3kPa) to P2(21.3kPa) (s)
T<10s: T=Time from P1(33.3kPa) to P2(13.3kPa) (s)
R² = 0.9653
60%
80%
100%
RD
M
R² = 0.9977
2.2
2.4
2.6
2.8
3.0
Ca
rbon
ati
on s
pee
dN
e(m
m/√
wee
k)
Deterioration assessment of existing structures
Experimental results
0%
20%
40%
1.0 1.2 1.4 1.6 1.8 2.0
RD
MCarbonation speed ratio Ne/Ni
1.6
1.8
2.0
2.2
0.10 0.15 0.20 0.25
Ca
rbon
ati
on s
pee
d
Permeability speed Kt(kPa/s)
Ne=2.4461ln(Kt)+6.6394 (1) RDM=-0.49(Ne/Ni)+1.4997 (2)
y = x
80%
100%
120%
mea
sure
d v
alu
e)
Deterioration assessment of existing structures
Experimental results
y = 0.9007x
R = 0.73
0%
20%
40%
60%
0% 20% 40% 60% 80% 100% 120%
RD
M (
mea
sure
d v
alu
e
RDM (estimation value)
Cover depth
Carbonation depth(cm)
Ni:Initial estimation valueNt:Measured value at tNe:Estimation value by permeability at t
Carbonation speed: N
Deterioration assessment of existing structures
DeteriorationDeteriorationDeteriorationDeterioration assessmentassessmentassessmentassessment and life time prediction
ttttmaxmaxmaxmax(Life time)(Life time)(Life time)(Life time)
Age (√year)
tttt ttttmaxmaxmaxmax’’’’(Life time)(Life time)(Life time)(Life time)
Carbonation depth(cm)
RDM=-0.49(Ne/Ni)+1.4997
Ne=2.4461ln(Kt)+6.6394
After t years, measure permeability Kt, carbonation depth Ct
DeteriorationDeteriorationDeteriorationDeterioration assessmentassessmentassessmentassessment and life time prediction
Mixture, environmental condition Initial carbonation speed: Ni
Deterioration assessment of existing structures
Calculate estimation carbonation speed Ne
from permeability Kt by eq(3.2)
Calculate RDM from Ne/Ni by eq(3.3)
Assessment of frost deterioration
Life time prediction
Future Study:
Life cycle prediction of structures
Simulation model for durability design
Permeability
Performance prediction system
Mechanism of frost deterioration
Mixture Materials
Neutralization
Weathering condition
Pore structure
PermeabilityMixture Materials
Diagnosis
technique
Equivalent cycles to ASTM C666 A
Temperature Humidity
Frost damage
Evaluation of environmental condition
Moisture in concrete