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2022 TRB ANNUAL MEETING� �State-of-the-Art Technologies to Detect & Evaluate Corrosion for Bridge Foundations�by�Ken Fishman, PhD, PE

Presented to AKG70 Standing Committee for

Foundations of Bridges & Other Structures

Tuesday January 11, 2022

Washington, DC

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AASHTO R27 – Standard Practice for Assessment of Corrosion of Steel Piling for Non-Marine Applications

  • Part 1 – Environmental Conditions Causing Corrosion of Steel Piling
  • Part 2 – Corrosion Considerations for New & Existing Piling
    • Phase 1 - Preliminary Assessment
    • Phase 2 - Site Investigation
      • Soil sampling and testing
      • Corrosion Monitoring

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CORROSION MONITORING

  • Corrosion Potential
    • Half-cell potential
    • Potential difference
  • Polarization
    • Linear Polarization Resistance (LPR)
    • Tafel test
  • Macrocell Current Measurement
  • Electrical Resistance Measurement (ERM)

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Field Corrosion Probe (Beavers & Durr, 1988)

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CONDITION ASSESSMENT

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CONDITION ASSESSMENT

  • Sonic echo (SE)
  • Impulse Response (IR)
  • Parallel Seismic
  • Induced Polarization (IP)
  • Ultrasonic
  • Reflective Impulse Measurement Technique (RIMT)

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IMPULSE RESP0NSE TEST FOR DRILLED SHAFT (Finno and Gassman, 1998)

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SE TEST RESULT

Normal

Distressed

IR TEST RESULT

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Location #

Stick-up

Water Depth

Top of plug

1

2.4

6.2

25.9

2

-

6.91

- 2

3

1.7

6.4

14.1

4

-

7.5

20.2

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Location

#

SE Results (ft. from top of pile)

½ Cell Potential

Soil Plug

Pile Tip

mV

1

25

29

-5391

2

25

29

-484

3

13

30

-5341

4

22

26

-551

5

-

 

-469

6

-

 

-429

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COMMENTS &CONCLUSIONS

  • Techniques are available for corrosion monitoring & condition assessment of bridge foundations, but they are not easy to implement.
  • Screen sites to identify need for identifying corrosion monitoring
  • Need to obtain as much as-built information as possible to compare and calibrate results from NDT and condition assessment
  • Cannot rely on results from NDT and electrochemical testing alone – need to confirm with visual observations- exhume/expose selected elements for inspection.