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

Outline • Modeling non-uniform corrosion • Comparison of model, experimental data • Influence of modeling non-uniform corrosion on surface crackning • Input/output • Future work 2

Modeling non-uniform corrosion Numerical model for the simulation of damage and cracking in concrete cover mean(i corr_uniform ) = mean(i corr_nonuniform ) 3

Comparison of model, experimental data • Digital image correlation (DIC) – 24.5 megapixel camera used for DIC during accelerated corrosion testing – Each pixel corresponds to 7.8×7.8 m m 2 of specimen surface Tap water Measured region Reinforced mortar specimen Steel bar - + Current regulator Non-conductive holders Activated titanium mesh (Pease et al., 2012) 4

Comparison of model, experimental data - deformations 6 4 2 mm 0 -7 -2 3 8 -2 -4 -6 mm Corrosion layer Reinforcement 5

Comparison of model, experimental data – crack width 1.4 mm from reinforcement 6

Influence of modeling non-uniform corrosion on surface crackning Crack Crack Corrosion Corrosion Reinforcement Reinforcement layer layer Semi-infinite concrete body Semi-infinite concrete body Scenario 2 Scenario 1 Crack Crack Corrosion Corrosion Reinforcement layer layer Reinforcement Semi-infinite concrete body Semi-infinite concrete body Scenario 3 Scenario 4 7

Influence of modeling non-uniform corrosion on surface crackning Scatter band 8

Input/output • 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

Future work • Probabilistic modeling of non-uniform corrosion – quantifying uncertainty • Multiple cracking in the cross section • Implementing penetration of corrosion products into cracks m (Pease et al., 2012) (Pease et al., 2006) 10

Future work • Mechanical modeling – initial defects – debonding Moisture, temperature, oxygen, chloride, carbon dioxide Concrete Cathode Cathode           O 2 H O 4 e 4 OH O 2 H O 4 e 4 OH Anode 2 2 2 2   2   Fe Fe 2 e Reinforcement (Michel et al., 2009) 11

Future work • Coupling with other models Microstructure Moisture Material and Ions transport models Temperature Oxygen Service life Resistivity prediction Cracking Oxygen Debonding Moisture (Michel et al., 2010) Temperature Properties 12

Thank you for your attention 13

Concrete body Corrosion layer Reinforcement 14