Life cycle management (LCM) and its international ...
Transcript of Life cycle management (LCM) and its international ...
JST Research MeetingD li 12 N b 2010Dalian, 12 November 2010
Life‐cycle management (LCM)and
its international standardizationits international standardization
Professor, Hokkaido University, Japan
Hiroshi YOKOTA, PhD, PE
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Life‐cycle of structure
Planning Requirements• Function
Basic design
Detail design Verification
• Function• Performance
1‐2 years
Detail design
Execution
Verification
Materials/Construction• Selection• Production
( l f )
1‐5 years
Maintenance • Assessment (incl. verification)• Evaluation• InterventionS i ti
50‐100 years
Replacement
• Scenario correction50 00 yea s
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ISO’s for concrete structures
Design Maintenance Lifecycle Management
Design Code
ISO 2394Maintenance
ISO/CD 16311
Role, Function, Activity, Importance
ISO 19338
ISO 15673
ISO/DIS 28841
/
ISO 13822 LCC, LCA, etc.Life‐cycle scenarioLink
ISO/DIS 28841
ISO/DIS 28842
ISO/WD 16204(Durability ‐ service life design)
Assessment, Performance
(Durability service life design)
Environmental t
Mainte‐nancePlmanagement
ISO/CD 13315Plan
Scenario
DB
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Performance (Safety, Serviceability, etc.)
Initial value
Minimum value
Initial level?Time
Design service life
STRATEGYSTRATEGYPerformance (Safety, Serviceability, etc.) Maintenance scenario?
STRATEGYSTRATEGYInitial value
Minimum value
Time
Design service life4
Life‐cycle management systemi f
Maintenance planDesignScenario for performance guarantee
Periodic inspection Input/Reference
Service periodUsage
p
Assessment and Prediction
p
DesignEnvironment
Assessment and Prediction
Performance Database・Inspection・Prediction
Input/Reference
Present Time
・Prediction・Intervention
Service life
Method of interventionInput/Reference
Future plan
Scenario correction 5
New Work Item Proposal
ISO/TC71/SC7 on 21 September at Cartagena, Colombia
Scope of proposed projectThis is to propose to prepare ISO document on life‐cycleThis is to propose to prepare ISO document on life cycle management of concrete structure including formulation of scenarios how structural performance of which would be guaranteed during the life span of the structure.
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New Work Item Proposal
Purpose and justificationConcrete structures should guarantee their structural performance over the required levels during their life spans. For this purpose, durability design including service life design and maintenance and repair workservice life design and maintenance and repair work have been installed. However, the initial design and further maintenance strategy are not linked each other. gyThere have been great needs of management methodologies to cover considering the structural performance during the whole life of structure. This International Standard deals with the methodologies to formulate scenarios how structural performance wouldformulate scenarios how structural performance would be guaranteed and how prioritization would be made by using some indexes such as life‐cycle cost,
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g y ,environmental impact, etc.
Provisional table of contents
ISO/WD xxxxx Life cycle management of concrete structuresForewordIntroduction1 S1. Scope2. Normative references3. Terms and definitions4. Life cycle management elements
4 1 General requirements4.1 General requirements4.2 Target, tactics and strategy4.3 Manage information and decision-making index
LCC, NPV, LCCO2, Energy consumption, LIME (?)4 4 Implementation and operation4.4 Implementation and operation4.5 Checking and corrective action
5. Structure planning6. Material production (concrete production)7 Design and performance verification7. Design and performance verification
Performance of structure in combination with initial performance and performance recovery strategy during service lifeDurability (Service life design)Structural robustness redundancy and integrityStructural robustness, redundancy and integrity
8. Execution9. Performance assessment
Prediction based on assessment dataScenario correction
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Scenario correctionDecision making for interventions
10. Replacement
ISO/TC59/SC14 Design Life (Secretariat: BSI)
ISO 15686 Buildings and constructed assets ‐ Service life planning
Part 1: General principlesPart 1: General principles
Part 2: Service life prediction procedures
Part 3: Performance audits and reviews
Part 4: Data dictionary (TR?)
Part 5: Whole‐life costing
Part 6: Procedures for considering environmental impacts
Part 7: Performance evaluation for feedback of service life data from practice
Part 8: Reference service life and service life estimationPart 8: Reference service life and service life estimation
Part 9: Guide on service life declarations for building products
Part 10: Data requirements
Part 11: Terminology
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Prediction of carbonation depth
ty dcbd (7.1.1)
yd : Carbonation depth :Safety factor
Carbonation depth
cb:Safety factord:Design carbonation rated = k e c
t D i i lift:Design service lifek:Characteristic value of carbonation ratee:Coefficient representing the extent of environmental action
)c:Material factor for concrete (= 1.0)
k = p pk p pp = -3.57 + 9.0 W/Cp:Safety factor for p
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Durability design for chloride‐induced deterioration
Mechanism of penetration and transportation of chloride ion in concrete are very complex.
Ex Modeling of Cl‐ penetration
,...,1,...,12
2
2
2
, baaww
aaww
aa
eaa ccf
x
D
xc
x
c
x
Dc
cD
t
c
Ex. Modeling of Cl penetration
, ,, ,22
ww xxxxxxt
Diffusion due to t ti di t
Water transportGeneration and disappearance by chemical reaction
concentration gradient
Electro‐migration of ions due to electrical potential gradient
Condensation due to water dissipation
Penetration of chloride ion into concrete is usually expressed as a simple diffusion equation. p q
2
2CD
t
Ca
(Fick’s second law of diffusion)2xt a (Fick s second law of diffusion)
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Prediction of corrosion initiation time
Chloride ion accumulates on the surface of steel bar over a certain amount => Threshold value
CoverFactors governing the corrosion
Cl‐Steel bar
Environment1) Supply of chloride ion
‐> C0: Surface chloride ion concentration(depending on the environment) l(depending on the environment)
2) Diffusivity of chloride ion in concrete> D : Apparent diffusion coefficient
Cl‐
‐> Dap: Apparent diffusion coefficient(depending on concrete quality)
3) Distance from the surface to rebar3) Distance from the surface to rebar‐> Cover depth
F 1) 3) b b i d/ ifi d b d il d i i
Dr Boonchai, Dr Wang will be contributing.
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Factors 1)‐3) can be obtained/quantified by detailed inspection
When is the passive‐film destroyed?
Lambert et al.
Lukas
Thomas et al
Tuutti
Locke & Siman
B f th t l
Hansson & Sorensen
Schiessl & Raupach
Thomas et al.
Elsener & Bohni
Henriksen
Bamforth et al.
Structure
Stratfull et al.
Vassie
West & HimeStructure
Out‐room test
In‐room test
0.0 0.5 1.0 1.5 2.0 2.5
Total chloride ion concentration (% wt. cement)
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Prediction of deterioration
(1) Assumed rule and process
ance
Initial (2) Present status
erform
(2) Present status
(3) Prediction
ctural p Present
Modification of
Struc
rule and processScenario correction
TimeAssessement
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An example of chloride ion profiles
S‐s S‐m S‐lSeaward Landward
12kg/m
3)
B‐s B‐m B‐lHWL
8
10
12
ntration(k B‐s
B‐mB‐lS‐sS‐m
4
6
onconcen S‐m
S‐l
0
2
0 20 40 60 80 100
Chlorideio
Depth from the surface (mm)C
Height from HWL and wave conditions washing the surface have some effects
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Surface chloride ion concentration, C0
Stain Spalling DelaminationCrack
10.7
15.116.915.7 12.713.5
16.9 11.8
10.59.2 10.5
9.9 10.8 10.7
15.3 15.5 11.0
15 9 16 8
16.5 15.3
12.711.4 7.1 10.6
8.07.8
8.0
11.0
15.1
12.811.5
15.9 16.8
15.3
13.1 16.9 11.5
14.5 8.6
12.3 6.315.4
11.512.8
13.5
10.6
(unit: kg/m3)
More than twice between the adjacent pointsMore than twice between the adjacent points
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Mass‐loss of steel barL it di l t l b
20
25
20-2515-20
20
2520-2515-2010-15
Longitudinal steel barMass‐loss (%)
Ave: 1.3%Std: 4.3%
)
質量減少率 (%)
Ave: 1.8%Std: 3.5%%
)
Longitudinal steel barMass‐loss (%)
5
10
1510-155-100-5
5
10
1510 155-100-5
Mass‐loss (%
Mass‐loss (%
50
35
0
65
0
95
0
12
50
15
50
18
50
323005397000
50
35
0
65
0
95
0
12
50
15
50
18
50
433205407810
Transverse steel bar Transverse steel bar
20
25
20
25
Ave: 0.8%Std: 2.5%
Ave: 1.0%Std: 2.1%
5
10
15
10
15
20
Mass‐loss (%)
Mass‐loss (%)
726
74
1
10
48
13
52
16
70
19
54
50
350
650
950
0
5
14835
2
16
70
19
54
350
6500
5
M
12
74271
12
742
674
1
10
41 50(unit: mm)
Mass‐loss Average cross‐sectional area loss 17
Envelope curves of load vs deflection
125
75
125
25
(kN
)
‐25Load
No‐corrosion
l h
‐125
‐75 Slight corrosion
Heavy corrosion
125
‐50 ‐25 0 25 50
Midspan deflection (mm)
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Corrosion of steel bar in concrete
cross‐sectional loss
rustrust
Grade‐c slab From Grade‐a slab
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Influence on localized corrosion
Yield load Ultimate loadYield load
0 8
1.0
0.8
1.0
tio
Ultimate load
0.6
0.8
oad
ratio
0 4
0.6
0.8
te load
rat
Wide spread corrosionWide spread corrosion
0.2
0.4
Yield l
0.2
0.4
Ultim
atWide spread corrosion
Localized corrosion Localized corrosion
0.00 10 20 30 40 50 60 70
Average cross‐sectional area loss (%)
0.00 10 20 30 40 50 60 70
g ( )
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Structural capacity vs deterioration grade
1.5
1.0 m load
Cal)
0.5
Maxim
um
(Exp/C
0 0
M
Exp.Ave.
0.0 d c b a
Deterioration grade
Grade Data Average SD -1 +1
d 2 1.07 0.03 1.04 1.10
c 10 1.06 0.25 0.81 1.31
b 8 1.04 0.25 0.79 1.29
a 8 0.76 0.24 0.51 1.00 21
Prediction by stochastic mathematical model
Physical deterioration models (Fick’s diffusion model, etc ) are based on relevant theories and may beetc.) are based on relevant theories and may be applicable for the service life design, but, in practice,1) Threshold value is not clear,1) Threshold value is not clear,2) Frequent coring is not preferable, and3) Very wide variations appear.
Consequently, other approaches are widely undertaken: Stochastic mathematical modelStochastic mathematical model1) Survival analysis when damage data are not available
ex. R(t)=(a+1)/(a+e (t-c) )
2) Markov model when damage data are available
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Markov model
The Markov model allows analysts to study events y ythat recur over time.
The Markov property states that the probability distribution for the system at the next step (and in fact at all future steps) only depends on the current t t f th t d t dditi ll thstate of the system, and not additionally on the state of the system at previous steps.
The changes of state of the system are calledThe changes of state of the system are called transitions, and the probabilities associated with various state‐changes are called transition gprobabilities.
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Tendencies of analysis
Probability px: 0.10 Year t: 10
Percentage t = 2
t = 20
ercentage
px = 0.01
px = 0.10px = 0.20
Grade of deterioration Grade of deterioration
P t = 40t = 60
Pe px = 0.30
47 years10 years 31 years
Actually inspected results
47 years
40
60
80
100
entage, %
10 years 3 yea s
0
20
40
0 I II III IV V
Perce
0 I II III IV V 0 I II III IV V
Grade of deterioration
0 I II III IV V 0 I II III IV V
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Transition probability, px
0.25
0.20
0.25RC beamRC slab
bility p
x The linear relationship is found between the probability and the rate of deterioration grade
0 10
0.15
on probab
the rate of deterioration grade.
0.05
0.10
Transitio
The probability can represent the deterioration rate.
0.000.00 0.05 0.10 0.15 0.20 0.25
d f d /Average grades of deterioration / year=The rate of deterioration
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LCC for scenario evaluation
108 Yen
LCC
InterventionI i i lInitial
P C P C P CBeam
P C P C P C P
Slab Preventive Corrective Improved preventive
Replacement
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NPV for scenario evaluation
108 YenLCC
BeamP C P C P C PBeam
Slab Preventive Corrective Improved preventive Replacementp
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Role of participating member (As of Mar. 2010)
Study item Study sub item Investigator
Damage Chloride ion ingress Jin, Takewakaassessment Frost damage Taguchi, Hama
Deterioration mechanism
Chloride ion ingress Ann, Boonchai, Jin, SugiyamaWang Takewaka (simulation)mechanism
and damage prediction
Wang, Takewaka (simulation)
Corrosion rate Boonchai (Withit), Takewaka
Frost damage Hama, Uedag
Combined actions Wittmann, Katsura, Sato
Service life prediction
Task Force to be set upprediction
Interventions Rehabilitation Ahmed, Zhang, Sato
Preventive measures Takewaka, Wittmann, Ann, ,
Guideline/Code
Durability design Performance assessment
Sugiyama, Wittmann
LCM Y k tLCM Yokota
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Contributions for standardizationConcept and framework of LCM
Performance: HU (Yokota)Environmental: HU (Sugiyama)
Scenario by durability designChloride‐induced deterioration: CU, DLUT, KU, ZJU, YUF t d MIT PWRIFrost damage: MIT, PWRICombined deterioration: QTU, HRO Intervention plan: HU (Sato)Carbonation (just refer)Carbonation (just refer)
Performance assessmentStructural capacity verification: HU (Sato), PARIChloride‐induced deterioration and corrosion: CU DLUT KU YU ZJUChloride induced deterioration and corrosion: CU, DLUT, KU, YU, ZJUFrost damage: MIT, HRO Combined:
Scenario for performance recoverySelection of rehabilitation: ASU, HU(Sugiyama, Sato), YUPerformance (mechanical and durability) recovery quantification: HU (Sato,
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( y) y q ( ,Sugiyama)Progress of deterioration after intervention: same as above
Thank you for your attention
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