1. The James Instruments Gecor 8 The James Instruments Gecor 8 NDT Symposium METU / Ankara, Turkey 5/4/2011 Presented By: Nestor Chonillo

2. Corrosion in Reinforced Concrete The permeability of liquids and gases to the concrete permit access of aggressive elements to the rebar.  Initiation of corrosion.

3. Consequences of corrosion

4. The exterior of a structure indicates the history of corrosion activity but not the present or future corrosion velocity.

5. Importance of non destructive electrochemical techniques for the evaluation of corrosion  Determine when repairs need to be done.  Evaluate the effectiveness of the repair.

6. u Corrosion Potential reading Risk of corrosion u Resistivity reading Degree of saturation of concrete I corr E corr  uReading of the Corrosion Velocity Sections of rebar loss non destructive electrochemical techniques for the evaluation of corrosion Técnicas electroquímicas

7. u Corrosion Potential reading Risk of corrosion u Resistivity reading Degree of saturation of concrete I corr E corr  Reading of the Corrosion Velocity Sections of rebar loss non destructive electrochemical techniques for the evaluation of corrosion QUALITATIVE QUANTITATIVE Técnicas electroquímicas

8. GECOR8 Central Processing unitCentral Processing unit Cu/CuSO 4 and Ag/AgCl SensorsCu/CuSO 4 and Ag/AgCl Sensors SENSOR A: Icorr, Ecorr SENSOR B: Res, Ecorr, risk of corrosion SENSOR C: Icorr, Ecorr

9. Mapping for resistivity and potential for rapid evaluation of a structure.Mapping for resistivity and potential for rapid evaluation of a structure. Current confinement method of aerial structuresCurrent confinement method of aerial structures Testing Methods incorporated in the Gecor 8: Measurement for submerged or very wet structures.Measurement for submerged or very wet structures. Measurement of cathodic protection.Measurement of cathodic protection.

10. Application layout of Gecor 8:

11. Mapping for resistivity and potential for rapid evaluation of a structure.Mapping for resistivity and potential for rapid evaluation of a structure. Current confinement method of aerial structuresCurrent confinement method of aerial structures Testing Methods incorporated in the Gecor 8 : Measurement for submerged or very wet structures.Measurement for submerged or very wet structures. Measurement of cathodic protection.Measurement of cathodic protection.

12.  Corrosion Potential (Ecorr)  Concrete Resistivity (K  xcm)  Combination of both parameters Mapping Of Resistivity and Potential

13. FOTO2 TEXTOS D >1.5D Mapping Of Resistivity and Potential  >100 - 200 K   low corrosion.  >100 - 200 K   low corrosion.  <100 - 200 K   Further analysis of parameters is suggested..  <100 - 200 K   Further analysis of parameters is suggested..

14. Mapping Of Resistivity and Potential D >1.5D

15. Mapping Of Resistivity and Potential

16. Map of Potential Map of Resistivity Risk of Corrosion

17. Mapping for resistivity and potential for rapid evaluation of a structure.Mapping for resistivity and potential for rapid evaluation of a structure. Current confinement method of aerial structuresCurrent confinement method of aerial structures Testing Methods incorporated in the Gecor 8 : Measurement for submerged or very wet structuresMeasurement for submerged or very wet structures. Measurement of cathodic protection.Measurement of cathodic protection.

18. STERN-GEARY Equation Theory of the linear polarization testing method. (Stern M. 1957) -Three electrode sistem (WE, CE & Ref) -Ohmic fall should be excluded due to the resistance of the heterogeneuos material. ( concrete) Técnicas electroquímicas

19. Currents will migrate toward localized corrosion areas. Confinement of currents is then needed. General considerations for in-situ corrosion readings Icorr in situ

20. u Linear Polarization method for Structures u Control and analyze effected area with suspicious readings. Corrosion velocity reading

21. Current confinement method

23. uTesting in Submerged or very wet structures uStructures with low resistivity Method of Attenuation of the Potential

25. Mapping for resistivity and potential for rapid evaluation of a structure.Mapping for resistivity and potential for rapid evaluation of a structure. Current confinement method of aerial structuresCurrent confinement method of aerial structures Testing Methods incorporated in the Gecor 8 : Measurement for submerged or very wet structuresMeasurement for submerged or very wet structures. Measurement of cathodic protection.Measurement of cathodic protection.

26. Cathodic Protection  Method of protecting rebar against corrosion.  External electrical currents applied to the rebar network

27. Cathodic Protection testing options  Disconnection of current supply: Corrosion Potential Reading. Reading of depolarization witin a 24 hr period.  Not disconnecting current supply: Pass or fail verification

28. “INSTANT OFF” POTENTIAL

29. Cathodic protection Effective testing method, no need to disconnect current supply. Induction of high current supply. Monitoring of stabilization for a 24 hr period. Utilizes confinement method.

30. Testing Noruega 2000 Catodic Protection Testing

31. Monitoring Cathodic Protection

32. GECOR8 Data Organization Program test Testing Results Print data & grapics Graphics GECOR 8 Post processing of Results

33. BASEGECOR GECOR 8 Predefine Task

34. BASEGECOR GECOR 8 Structure information

35. Types of graps Types of Graphs BASEGECOR GECOR 8

36. Conclusion  Potential and resistivity analysis only determine qualititive information. Risk of structure.  Velocity reading of corosion determine at wat rate rebar loss is occuring. Estimate life of structure.