reinforcement corrosion: numerical simulation and service ......reinforcement corrosion: numerical...
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Reinforcement Corrosion: Numerical Simulation and Service Life PredictionAlexander Michel & Henrik Stang
Sponsored by • Femern Bælt A/S• Sund & Bælt Holding A/S• The Danish Agency for Science, Technology and
Innovation
Dansk Ekspertcenter for konstruktioner til infrastrukturen– resultater og perspektiver
March 14th 2013Copenhagen, Denmark
DTU Civil Engineering, Technical University of Denmark
BACKGROUND AND MOTIVATION
• Deterioration of the civil infrastructure presents major challenges to society
• Costs for maintenance, renovation, and renewing are growing and taking up a major part of concrete structure investments
– US > $ 20 billion (infrastructure, 2002)– UK > £ 550 million (annual costs, 2005)– Toronto > $ 110 million (roads, sidewalks and bridges, 2005)
2 15 March 2013
http://corrosion.ksc.nasa.gov
http://www.matcoinc.com
http://www.zoranthepainter.com.au
DTU Civil Engineering, Technical University of Denmark
STATE-OF-THE-ART (1 OF 2)• Service life modelling
– ingress of corrosion-initiating substances– propagation phase is (often) neglected
3 15 March 2013
[Tuutti 1982]
Con
dit
ion
of
Str
uct
ure
Initiation phase Propagation phase
Typical service life model
End of service
life
Age of Structure
DTU Civil Engineering, Technical University of Denmark
STATE-OF-THE-ART (2 OF 2)• Service life modelling
– ingress of corrosion-initiating substances– propagation phase of reinforcement corrosion
4 15 March, 2013
[Pease et al. 2012]
Con
dit
ion
of
Str
uct
ure
Initiation phase Propagation phase
Typical service life model
End of service
life
Age of Structure
Modified service life model
Initiationphase
Propagation phase
DTU Civil Engineering, Technical University of Denmark
SCOPE (1 OF 2)• Conceptual model for service life modelling
– ingress of corrosion-initiating substances– propagation phase of reinforcement corrosion– corrosion-induced damage
5 15 March, 2013
CathodeCathode
Reinforcement
Concrete
Moisture, temperature, oxygen, chloride, carbon dioxide
Anode
DTU Civil Engineering, Technical University of Denmark
Microstructure
Temperature
Moisture Ions
Oxygen
Resistivity
Temperature
Moisture
Ions
Oxygen
Cracking
Debonding
Properties
Material and transport
model
Servicelife
prediction
SCOPE (2 OF 2)
6 15 March 2013
[Michel et al. 2010]
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
7 15 March 2013
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
8 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
TRANSPORT OF HEAT AND MASS IN CONCRETE
• Mass balance equations
• Comparison experimental and numerical results
9 15 March, 2013
Microstructure
Temperature
Moisture Ions
Oxygen
Material and transport
model
Servicelife
prediction
, , T T T pCTC k T k pCt
, , l cpC pC pC pC T
c
p pCC k pC k Tp pC t
Reinforcement
Concrete
Moisture and temperature
DTU Civil Engineering, Technical University of Denmark
TRANSPORT OF HEAT AND MASS IN CONCRETE
• Nernst-Planck equation
• Comparison experimental and numerical results
10 15 March, 2013
Microstructure
Temperature
Moisture Ions
Oxygen
Material and transport
model
Servicelife
prediction
,i
i i i m i i ic D c z u Fc V c vt
2 2 24, , , , ,i Cl OH SO Ca Na K Mg
Reinforcement
Concrete
Ions (e.g.: chloride)
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
11 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
CORROSION OF STEEL IN CONCRETE
• Modelling reinforcement corrosion
– corrosion current and potential
– polarisation
12 15 March, 2013
Resistivity
Temperature
Moisture
Ions
Oxygen
Servicelife
prediction 1corr
conc
Ein
2 0E
0, A A Ai i exp
C0,
0, lim C
11 i / iC C
Ci i exp
0, /A/C 10 A CE E
lnb
10 RTb lnzF
22
Olim O
zFDi cCathodeCathode
Concrete
Moisture, temperature, oxygen, chloride
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark
CORROSION OF STEEL IN CONCRETE
• Influence of temperature
• Comparison experimental and numerical results
13 15 March, 2013
Resistivity
Temperature
Moisture
Ions
Oxygen
Servicelife
prediction0
0, 0,1 1
T RefRef
zFEi i expR T T
CathodeCathode
Concrete
Temperature
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark
CORROSION OF STEEL IN CONCRETE
• Influence oxygen
14 15 March, 2013
Resistivity
Temperature
Moisture
Ions
Oxygen
Servicelife
prediction
[Raupach 1996]
CathodeCathode
Concrete
Oxygen
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark
CORROSION OF STEEL IN CONCRETE
• Influence of moisture
15 15 March, 2013
Resistivity
Temperature
Moisture
Ions
Oxygen
Servicelife
prediction(all dimensionsin mm)
Anodes
Cathode
CathodeCathode
Concrete
Moisture
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
16 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
INITIATION AND PROPAGATION OF CORROSION
• Definition of a conditional statement (critical chloride threshold) for elements along the reinforcement surface
17 15 March, 2013
a cl critSteel
c cl crit
i c cBC for
i c c
Material and transport
model
Servicelife
prediction
CathodeCathode
Concrete
Moisture, temperature, oxygen, chloride
Anode
Reinforcement
0
-90
90
180
0.05%
0.20%
Concrete
Rebar
Rebar
Chloride
DTU Civil Engineering, Technical University of Denmark
INITIATION AND PROPAGATION OF CORROSION
18 15 March, 2013
(all dimensions in m)CathodeCathode
Concrete
Moisture, temperature, oxygen, chloride
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark
INITIATION AND PROPAGATION OF CORROSION
19 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
IMPACT OF CRACKS
20 15 March, 2013
(all dimensions in m)
Material and transport
model
Servicelife
prediction
DTU Civil Engineering, Technical University of Denmark
IMPACT OF CRACKS
21 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
22 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
CORROSION-INDUCED CONCRETE DAMAGE
• Modelling approach– uniform corrosion along the
reinforcement– 2D plain strain formulation
23 15 March, 2013
CathodeCathode
Reinforcement
Concrete
Moisture, etc.
Anode
Non corrodedreinforcementsection
Corrodedreinforcementsection
Expandedcorrosionlayer
R0
R1
R2
R0=R2 R0
T
R0=(R0 R1)• • T
0
tFe
corrFe
MX t i t dtzF
Material and transport
model
Servicelife
prediction
DTU Civil Engineering, Technical University of Denmark
CORROSION-INDUCED CONCRETE DAMAGE
• Penetration of corrosion products
24 15 March, 2013
[Pease et al. 2012]
DTU Civil Engineering, Technical University of Denmark
CORROSION-INDUCED CONCRETE DAMAGE
• Non-uniform corrosion
25 15 March, 2013
[Thybo et al. 2013]
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
26 15 March, 2013
DTU Civil Engineering, Technical University of Denmark27
SUMMARY AND CONCLUSIONS
• Coupled transport and corrosion processes– allow for the simulation of initiation and propagation of chloride-
induced corrosion in reinforced concrete– may be used to predict the service life of reinforced concrete if a
certain limit state, e.g. initiation of corrosion or certain cross sectional reduction, is set
– governing parameters can be assessed with the model and used to optimise structures in terms of service life
15 March, 2013
Material and transport
model
Service life
prediction CathodeCathode
Concrete
Moisture, temperature, oxygen, chloride
Anode
Reinforcement
DTU Civil Engineering, Technical University of Denmark28
SUMMARY AND CONCLUSIONS
• Corrosion-induced concrete damage– thermal analogy may be used to mimic any type of solid corrosion
product that is formed– penetration of corrosion products into cementitious materials has a
considerable influence on the time-to crack initiation and propagation– model can be used to investigate the impact of varying geometrical
parameters and material properties on the formation and propagation of cracks
15 March, 2013
Material and transport
model
Service life
prediction CathodeCathode
Reinforcement
Concrete
Moisture, etc.
Anode
DTU Civil Engineering, Technical University of Denmark29
SUMMARY AND CONCLUSIONS
• Impact of cracks– allow to account for the impact of cracks on the ingress of potential
corrosion-initiating substances – provide more realistic predictions on the initiation and propagation of
reinforcement corrosion
15 March, 2013
CathodeCathode
Reinforcement
Concrete
Moisture, etc.
Anode
Material and transport
model
Service life
prediction
DTU Civil Engineering, Technical University of Denmark
OUTLINE OF PRESENTATION
• Transport of heat and mass in concrete– Coupled heat and moisture transport– Multi-ion transport
• Corrosion of steel in concrete– Modelling of reinforcement corrosion– Influence of temperature, oxygen, and moisture
• Initiation and propagation of reinforcement corrosion
• Corrosion-induced concrete damage– Modelling approach– Penetration of corrosion products
• Summary and conclusions
• Future developments
30 15 March, 2013
DTU Civil Engineering, Technical University of Denmark
ShapeMaterial
Properties
StructuralProperties
Loads
Maintenance
InfrastructurePerformance
Materials
Structure
System
EnvironmentalIndicators
InfrastructureSustainability
SocialIndicators
EconomicIndicatorsEvaluation
MaterialProduction
Constituents
MaterialMicrostructure
Construction
Design for Sustainability
Life CycleAssessment
FUTURE DEVELOPMENTS (1 OF 2)• Establish a cross disciplinary research approach including
– industrial ecology methods, quantitative sustainability assessment practices, environmental impact measurement,ecosystem service valuation, social impact measurement, life cycle costing,
– theoretical infrastructure deterioration modelling, advanced materials design,
– emerging transportation infrastructure,innovations, risk and reliability of transportation infrastructure,
– and probabilistic design methods
31 15 March, 2013
[Lepech et al. 2011]
DTU Civil Engineering, Technical University of Denmark
FUTURE DEVELOPMENTS (2 OF 2)
32 15 March, 2013
Structural Performance
Module (3D +Time)Structural Capacity
Sustainability Indicators
Material PerformanceModule (3D + Time)
Corrosion RatesCorrosion Potentials
Types of Corrosion Products
Mechanical Performance
Module (2D + Time)Corrosion-induced DamageChemical-induced Damage
Transport and Chemical Module (1D + Time)
States of Heat and MatterChemical Compositions
Changes in Microstructure
InterfaceModule
[Michel et al. 2013]
DTU Civil Engineering, Technical University of Denmark
COMMITMENT
33 15 March, 2013
• Expert-center commitment to establish poof of concept model and to work on experimental verification
• Further commitment (involving existing projects and seeking funding for new) from:
– Stanford University (sustainability, exposure simulation and structural performance)
– DTU (transport, corrosion and construction of the unified model)– NTNU (transport corrosion and structural performance)
• Foreseen commitment from:– Danish road Directorate (real bridge) – …
DTU Civil Engineering, Technical University of Denmark
Thank you for your attention
34
[Küter 2009]