Reinforcement Corrosion: Numerical Simulation and Service Life Prediction

Transcription

1 Corrosion: Numerical Simulation and Life Prediction Alexander 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 14 th 2013 Copenhagen, 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) DTU Civil Engineering, Technical University of Denmark 15 March 2013

2 STATE-OF-THE-ART (1 OF 2) ling ingress of corrosion-initiating substances propagation phase is (often) neglected Age of Structure Initiation phase Propagation phase Condition of Structure End of service Typical service [Tuutti 1982] 3 DTU Civil Engineering, Technical University of Denmark 15 March 2013 STATE-OF-THE-ART (2 OF 2) ling ingress of corrosion-initiating substances propagation phase of reinforcement corrosion Age of Structure Initiation phase Propagation phase Condition of Structure Propagation phase Initiation phase End of service Typical service Modified service [Pease et al. 2012] 4 DTU Civil Engineering, Technical University of Denmark

3 SCOPE (1 OF 2) Conceptual for service ling ingress of corrosion-initiating substances propagation phase of reinforcement corrosion corrosion-induced damage Moisture,temperature,oxygen,chloride,carbondioxide Anode 5 DTU Civil Engineering, Technical University of Denmark SCOPE (2 OF 2) Microstructure Moisture Material and Ions Resistivity Cracking Ions Debonding Moisture Properties [Michel et al. 2010] 6 DTU Civil Engineering, Technical University of Denmark 15 March 2013

4 OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark 15 March 2013 OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark

5 TRANSPORT OF HEAT AND MASS IN CONCRETE Microstructure Moisture Material and Ions Mass balance equations T C ktt, T kt, pcpc t Comparison experimental and numerical results l pc pc CpC kpc, pcpc kpc, TT pc pc t Moisture and temperature 9 DTU Civil Engineering, Technical University of Denmark TRANSPORT OF HEAT AND MASS IN CONCRETE Microstructure Moisture Material and Ions Nernst-Planck equation ci Dici zium, ifciv civ t i Cl, OH, SO4 Ca, Na, K, Mg Comparison experimental and numerical results Ions (e.g.: chloride) 10 DTU Civil Engineering, Technical University of Denmark

6 OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark CORROSION OF STEEL IN CONCRETE Modelling reinforcement corrosion Moisture Resistivity Ions corrosion current and potential 1 E icorr conc n 2 E 0 polarisation ia i0, Aexp A Moisture, temperature, oxygen, chloride Anode 1 i C C i0, Cexp 1 i 0, C /ilim C E E A/C 10 b 0, A/ C ln b ln zfd i O2 lim co2 10 RT zf 12 DTU Civil Engineering, Technical University of Denmark

7 CORROSION OF STEEL IN CONCRETE Influence of temperature Moisture Resistivity Ions zfe0 1 1 i0, T i0, Refexp R T TRef Comparison experimental and numerical results Anode 13 DTU Civil Engineering, Technical University of Denmark CORROSION OF STEEL IN CONCRETE Influence oxygen Resistivity Ions Moisture [Raupach 1996] Anode 14 DTU Civil Engineering, Technical University of Denmark

8 CORROSION OF STEEL IN CONCRETE Influence of moisture Resistivity (all dimensions in mm) Ions Moisture Anodes Moisture Anode 15 DTU Civil Engineering, Technical University of Denmark OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark

9 INITIATION AND PROPAGATION OF CORROSION Definition of a conditional statement (critical chloride threshold) for elements along the reinforcement surface Moisture, temperature, oxygen, chloride Anode ia ccl ccrit BCSteel for ic ccl ccrit Material and Chloride 180 Rebar 0.05% % 0 Rebar 17 DTU Civil Engineering, Technical University of Denmark INITIATION AND PROPAGATION OF CORROSION Moisture, temperature, oxygen, chloride Anode (all dimensions in m) 18 DTU Civil Engineering, Technical University of Denmark

10 INITIATION AND PROPAGATION OF CORROSION 19 DTU Civil Engineering, Technical University of Denmark IMPACT OF CRACKS Material and (all dimensions in m) 20 DTU Civil Engineering, Technical University of Denmark

11 IMPACT OF CRACKS 21 DTU Civil Engineering, Technical University of Denmark OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark

12 CORROSION-INDUCED CONCRETE DAMAGE Material and Modelling approach uniform corrosion along the reinforcement 2D plain strain formulation t M X Fe t icorr t dt zf Fe 0 Moisture, etc. Corroded reinforcement section R 0 T Anode Noncorroded reinforcement section R 0 =(R 0 R 1 ) T R 1 R2 R 0 =R 2 R 0 Expanded corrosion layer 23 DTU Civil Engineering, Technical University of Denmark CORROSION-INDUCED CONCRETE DAMAGE Penetration of corrosion products [Pease et al. 2012] 24 DTU Civil Engineering, Technical University of Denmark

13 CORROSION-INDUCED CONCRETE DAMAGE Non-uniform corrosion [Thybo et al. 2013] 25 DTU Civil Engineering, Technical University of Denmark OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark

14 SUMMARY AND CONCLUSIONS Coupled and corrosion processes allow for the simulation of initiation and propagation of chlorideinduced corrosion in reinforced concrete may be used to predict the service 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 and used to optimise structures in terms of service Moisture, temperature, oxygen, chloride Material and Anode 27 DTU Civil Engineering, Technical University of Denmark 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 can be used to investigate the impact of varying geometrical parameters and material properties on the formation and propagation of cracks Moisture, etc. Material and Anode 28 DTU Civil Engineering, Technical University of Denmark

15 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 s on the initiation and propagation of reinforcement corrosion Moisture, etc. Material and Anode 29 DTU Civil Engineering, Technical University of Denmark OUTLINE OF PRESENTATION Transport of heat and mass in concrete Coupled heat and moisture Multi-ion 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 DTU Civil Engineering, Technical University of Denmark

16 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, cycle costing, theoretical infrastructure deterioration ling, advanced materials design, emerging ation infrastructure, Material Properties Material Production innovations, risk and reliability of ation infrastructure, and probabilistic design methods Structural Properties Materials Infrastructure Performance Structure Material Microstructure System Loads Shape Construction Constituents Maintenance Social Indicators Design for Sustainability Life Cycle Assessment Environmental Indicators Evaluation Infrastructure Sustainability Economic Indicators [Lepech et al. 2011] 31 DTU Civil Engineering, Technical University of Denmark FUTURE DEVELOPMENTS (2 OF 2) Structural Performance Module (3D +Time) Structural Capacity Sustainability Indicators Interface Module Material Performance Module (3D + Time) Corrosion Rates Corrosion Potentials Types of Corrosion Products Mechanical Performance Module (2D + Time) Corrosion-induced Damage Chemical-induced Damage Transport and Chemical Module (1D + Time) States of Heat and Matter Chemical Compositions Changes in Microstructure [Michel et al. 2013] 32 DTU Civil Engineering, Technical University of Denmark

17 COMMITMENT Expert-center commitment to establish poof of concept 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 (, corrosion and construction of the unified ) NTNU ( corrosion and structural performance) Foreseen commitment from: Danish road Directorate (real bridge) 33 DTU Civil Engineering, Technical University of Denmark Thank you for your attention [Küter 2009] 34 DTU Civil Engineering, Technical University of Denmark