Reinforcement Corrosion in Cracked Concrete Prepared by: Anna - - PowerPoint PPT Presentation

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

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Outline

Numerical model for the simulation of damage and cracking in concrete cover

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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

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Comparison of model, experimental data

+

• Tap water

Steel bar Reinforced mortar specimen Current regulator Activated titanium mesh Non-conductive holders Measured region

(Pease et al., 2012)

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Comparison of model, experimental data

• deformations
• 6
• 4
• 2

2 4 6

• 7
• 2

3 8 mm mm Corrosion layer Reinforcement

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Comparison of model, experimental data – crack width 1.4 mm from reinforcement

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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

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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

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Input/output

• Probabilistic modeling of non-uniform corrosion

– quantifying uncertainty

• Multiple cracking in the cross section
• Implementing penetration of corrosion products

into cracks

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Future work

m

(Pease et al., 2012) (Pease et al., 2006)

• Mechanical modeling

– initial defects – debonding

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Future work

Cathode Cathode Reinforcement Concrete

     OH e O H O 4 4 2 2 2      OH e O H O 4 4 2 2 2

Moisture, temperature, oxygen, chloride, carbon dioxide

    e Fe Fe 2 2

Anode

(Michel et al., 2009)

• Coupling with other models

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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

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Concrete body Corrosion layer Reinforcement