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Midterm presentation of Numerical Modeling of Reinforcement Corrosion in Cracked Concrete
Prepared by: Anna Emilie A. Thybo
Prepared for: Concrete Expert Centre Reference Group Closing Meeting, November 30, 2012
• Modeling non-uniform corrosion
• Comparison of model, experimental data
• Influence of modeling non-uniform corrosion on surface crackning
• Input/output
• Future work
2
Outline
Numerical model for the simulation of damage and cracking in concrete cover
3
Modeling non-uniform corrosion
mean(icorr_uniform) = mean(icorr_nonuniform)
• Digital image correlation (DIC)
– 24.5 megapixel camera used for DIC during accelerated corrosion testing
– Each pixel corresponds to 7.8×7.8 mm2 of specimen surface
4
Comparison of model, experimental data
+-
Tap water
Steel bar
Reinforcedmortar specimen
Currentregulator
Activated titanium meshNon-conductive holders
Measured region
(Pease et al., 2012)
5
Comparison of model, experimental data - deformations
-6
-4
-2
0
2
4
6
-7 -2 3 8
mm
mm
Corrosion layer Reinforcement
6
Comparison of model, experimental data – crack width 1.4 mm from reinforcement
7
Influence of modeling non-uniform corrosion on surface crackning
Corrosion layer
Semi-infinite concrete body
Semi-infinite concrete body Semi-infinite concrete body
Corrosion layer
Corrosion layer
Semi-infinite concrete body
Corrosion layer
Reinforcement Reinforcement
Reinforcement Reinforcement
Crack Crack
Crack Crack
Scenario 1 Scenario 2
Scenario 3 Scenario 4
8
Influence of modeling non-uniform corrosion on surface crackning
Scatter band
• INPUT – Material parameters (concrete, steel and corrosion
products)
– Geometrical parameters (incl location of corrosion products)
– Corrosion current density
– Time
• OUTPUT – Thickness of corrosion layer/reduction of steel area
– Crack width in concrete cover
9
Input/output
• Probabilistic modeling of non-uniform corrosion
– quantifying uncertainty
• Multiple cracking in the cross section
• Implementing penetration of corrosion products into cracks
10
Future work
0 1 2 3 4 5 6 7 8 9
Time (days)
-2
0
2
4
6
8
Cra
ck w
idth
(m
m)
Crack 1
Crack 2
Crack 3
'Dummy'Crack
(Pease et al., 2012) (Pease et al., 2006)
• Mechanical modeling
– initial defects
– debonding
11
Future work
CathodeCathode
Reinforcement
Concrete
OHeOHO 44
22
2
OHeOHO 44
22
2
Moisture, temperature, oxygen, chloride, carbon dioxide
eFeFe 2
2
Anode
(Michel et al., 2009)
• Coupling with other models
12
Future work
(Michel et al.,
2010)
Microstructure
Temperature
Moisture Ions
Oxygen
Resistivity
Temperature
Moisture Oxygen
Cracking
Debonding
Properties
Material and transport models
Service life
prediction
Thank you for your attention
13
14
Concrete body
Corrosion layer
Reinforcement
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