STADIUM Software Overview. Durability and Service Life of Concrete Structures

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1 STADIUM Software Overview Durability and Service Life of Concrete Structures Eric Samson Cementitious Barriers Partnership SIMCO Technologies Inc. August 2014

2 Who we are SIMCO is a specialized engineering firm entirely dedicated to the durability of concrete structures. 2

3 Who we are Design Construction Maintenance Rehabilitation Cumulative Damage WITHOUT INTERVENTION CURRENT CONDITION REPAIR Time 3

4 Who we are 4

5 STADIUM Overview STADIUM models the transport of chemical species in cementitious materials resulting from exchanges at the material/environment interface. Exchanges Transport (dissolved species in pores) Chemistry (Interaction of dissolved species with hydrated cement) 5

6 STADIUM Overview 6

7 STADIUM Overview Influence of local materials Multiple degradation phenomena Specific geometry of the structure Influence of local exposure conditions Rehabilitation analyses 7

8 STADIUM Overview The U.S. Department of Defense recognizes STADIUM as the only accurate numerical solution for the prediction of longterm behavior of reinforced concrete structures exposed to marine environments. Since 2010, STADIUM is specified in the Unified Facilities Guide Specifications (UFGS). It is used to select concrete mixtures for marine applications, based on specified performance targets. 8

9 STADIUM Overview Next time step Input parameters: Material properties Environment Geometry Transport Module Chemistry Module No End of calculation? Yes The model is divided in 2 main modules: The transport module makes the species move during one time step, The chemistry module simulates the reactions between species in the pores and the hydrated paste. Model output 9

10 STADIUM Overview Next time step Input parameters: Material properties Environment Geometry Transport Module Chemistry Module No End of calculation? Coupled species diffusion Moisture/Temperature coupling Transport of main species Feedback effect Time dependent transport properties (hydration) Time dependent B.C. Yes Model output 10

11 STADIUM Overview Input parameters: Material properties Environment Geometry Next time step Transport Module Chemistry Module No End of calculation? Yes Local Equilibrium Assumption Dissolution/precipitation Solid solutions Chemical/Pitzer database in separate text file Effect of temperature on chemistry Model output 11

12 STADIUM Lab Modules Characterization of concrete mixtures Evaluation of transport properties Input to STADIUM Drying test Migration test Permeability Moisture isotherm Tortuosity Diffusion coefficients 12

13 STADIUM Lab Modules The test methods are part of Unified Facilities Guide Specifications (UFGS) (February 2010) test protocol US Navy (NAVFAC ESC) USACE USAF NASA 13

14 STADIUM Input Transport equations Mechanisms Properties Lab tests Electrodiffusion of species Moisture transport (liquid &vapor) Heat conduction Diffusion coefficient Porosity Permeability Moisture isotherm Thermal conductivity Heat capacity Migration test ASTM C642 Drying test Drying test Estimated Estimated 14

15 STADIUM Input Chemistry INPUT TO CHEMISTRY MODULE CALCULATED PARAMETERS Mix composition Cement chemistry SCMs chemistry Chemistry database Pitzer parameters Hydrated cement paste composition Pore solution composition 15

16 STADIUM Input Time dependent boundary conditions Exposure to deicing salts during winter After a one-year cycle, the model goes back to the beginning of the year. The cycle is repeated. 16

17 Using STADIUM New structures Existing structures Input values Input values Calculations Calculations OUTPUT OUTPUT 17

18 Using STADIUM Existing Structures Time to initiate corrosion Current age of the structure Corrosion initiation 10 years 18

19 Using STADIUM Existing Structures Maintenance options Chloride content at first rebar No Repair Membrane Overlay Patch Repair 19

20 Using STADIUM Existing Structures Simulating past exposure sequences 20

21 Using STADIUM Existing Structures Simulating past exposure sequences Overlay Original Concrete 21

22 Using STADIUM Existing Structures Simulating past exposure sequences 22

23 Using STADIUM New Structures Case Studies Kentucky University Concrete Mix Design 23

24 Using STADIUM New Structures Case Studies STADIUM Specified Kilo Wharf Extension Kilo Wharf Extension US NAVY, GUAM 24

25 Using STADIUM New Structures Case Studies Panama Canal Third Set of Locks 25

26 Using STADIUM New Structures Case Studies Panama Canal Third Set of Locks Two Coring Drill Diameter m High Water Mark 26

27 Probabilistic approach A probabilistic engine can handle calculations considering the distribution of key parameters: Transport properties, Concrete cover, Exposure conditions, Corrosion threshold. Transport properties Exposure conditions NDT / Rebar depth Probabilistic Layer Rosenblueth point est. 27

28 Probabilistic approach 28

29 Probabilistic approach TRANSPORT PROPERTIES EXPOSURE MAP REBAR DEPTH STADIUM Corrosion Simulations 29

30 Asset Management KMS Kademuren Modellering Systeem

31 Asset Management KMS Kademuren Modellering Systeem STEP KAD 001 A 037 KAD 001 B 037 KAD 001 C Inspection Request Concrete Steel Coring Visual Inspection Corrosion Measurements Pitting Evaluation Mechanical Testing STADIUM Testing 31

32 Asset Management KMS Kademuren Modellering Systeem STEP 2 Degradation Analysis per Zone and Element Evaluate Degradation with STADIUM Post Treatment Analysis For each Zone/Element combination Select the most critical Zone/Element combination Critical Year (Trigger/Intervention) Schedule Next Inspection Close Monitoring Required Repair Maintenance Proposal 32

33 CBP Test Case Concrete in contact with saltstone x = L Waste material (saltstone) Concrete barrier 20 cm x = 0 Soil 33

34 CBP Test Case Concrete in contact with saltstone x = L Waste material (saltstone) Concrete barrier 20 cm Solid phase content (g/kg) Minerals after 5000 years Portlandite CaH2SiO4 Ettringite Monosulfate C4AH13 Calcite Monocarboal Concrete Saltstone 20 x = 0 Soil Position (cm) 34

35 CBP Test Case Concrete in contact with saltstone x = L Species (liquid phase) after 5000 years Waste material (saltstone) Concrete barrier 20 cm x = 0 Soil 35

36 CBP Test Case Concrete in contact with saltstone x = L x = 0 Waste material (saltstone) Concrete barrier Soil 20 cm SO4 Concentration (mmol/l) Sulfate concentration at the concrete/saltstone interface Time (years) 36

37 CBP Test Case Concrete in contact with saltstone x = L Waste material (saltstone) Position of the ettringite front Concrete barrier 20 cm x = 0 Soil 37