Effectiveness of FRP in Reducing Corrosion in a Marine Environment

Transcription

1 Effectiveness of FRP in Reducing Corrosion in a Marine Environment Rajan Sen, Gray Mullins and Danny Winters Department of Civil & Environmental Engineering USF, Tampa FL K S Suh PB Americas, Inc. Tampa FL 2009 US Army Corrosion Summit Clearwater, FL 1

2 Report Documentation Page Form Approved OMB No Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE FEB REPORT TYPE 3. DATES COVERED to TITLE AND SUBTITLE Effectiveness of FRP in Reducing Corrosion in a Marine Environment 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of South Florida,Department of Civil & Environmental Engineering,4202 E. Fowler Ave,Tampa,FL, PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR S ACRONYM(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 2009 U.S. Army Corrosion Summit, 3-5 Feb, Clearwater Beach, FL 14. ABSTRACT 11. SPONSOR/MONITOR S REPORT NUMBER(S) 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Same as Report (SAR) 18. NUMBER OF PAGES 37 19a. NAME OF RESPONSIBLE PERSON Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

3 Pile Corrosion 2 Courtesy - Alltrista

4 Pile Corrosion 3 Courtesy - Alltrista

5 Test Program Structural Repair Structural Repair 10 specimens 6 controls 4 for gravimetric testing 2 for evaluating expansion 4 wrapped specimens 22 in. 40 in. 2 wrapped after 10% steel loss 2 wrapped after 20% steel loss 5/16 in. grade 250 low relaxation strands 3.27 in. 6 in. 1 in. #5 spiral 4

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7 Outline Background Test Program Findings Field Applications Concluding Remarks Acknowledgements 6

8 Project Goals How effective is FRP in mitigating corrosion? How important is the pre-wrap repair? (Not covered) How feasible is it to conduct field repairs? 7

9 Tuutti s Corrosion Model Max. Acceptable Steel Loss Initiation Stage Propagation Stage Time FRP Wrap Limit of Service Life 8

10 Test Specimen 6 controls 16 wrapped 4 strands and ties C Titanium electrode 15 cm 1.5m or 1.8m FRP chloride contaminated area chloride contaminated area 1.8 m specimens 1.5 m specimens Titanium reference electrode 9

11 ATR Reference Electrode Thermocouple Thermocouple Reference Electrode 10

12 Concrete + chlorides 11

13 FRP Wrapping 28 days Glass Carbon 1, 2, 3, 4 layers 1, 2, 3, 4 layers 12

14 Carbon Fiber Wrap Glass Fiber Wrap 13

15 Ambient Exposure - 3.5% salt water - Wet/dry cycles: every 6 hrs days (3 yrs 2 months) Indoor Outdoors 14

16 Controls vs Wrapped Specimens Cracked 15

17 Effect on Corrosion Rate 16

18 Role of Layers - CFRP 17

19 Role of Layers - GFRP 18

20 Unwrapped Controls 19

21 Wrapped Specimens 20

22 Retrieved Strands Outdoor Control 30 wire breaks in 6 controls CFRP Wrapped 1 wire break in 16 FRP specimen 21

23 1/3 rd Metal Loss in Wrapped Specimens Strand Tie Steel Loss (%) layer 1 layer 2 layers 3 layers 4 layers Wrapping Layers 22

24 Implications Steel Loss Limit of Service Life Initiation of Crack Initiation of Corrosion FRP Wrap Time 23

25 Why? Tests are underway to evaluate FRP s performance as a barrier If possible, we would like to evaluate coatings that could conceivably be used to improve FRP s performance 24

26 NSF Funded Study 25

27 Field Validation 26

28 Field Demonstration Studies Allen Creek Bridge, Clearwater Allen Creek Bridge Gandy Bridges Friendship Trails Bridge Gandy Bridge 27

29 Gandy Bridge, Tampa Linear Polarization 28

30 Junction Box Installation 29

31 Measured Corrosion Rates in Controls vs Wrapped Piles Pile Date Rate (mm/yr) Control 91 cm above HWL Nov Jun Aug Control Nov cm Below HWL Jun Aug Wrapped Pile 91 cm above HWL Wrapped Pile 31 cm Below HWL Nov Jun July Nov Jun July

32 Latest Application 31

33 Grove Isle Bridge, Miami January 2009 Pile Corrosion 32

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36 CP + Wrap + Pressure Bag NCHRP-IDEA

37 Concluding Remarks FRP slows down the corrosion rate Performance of CFRP and GFRP are comparable Performance appears to be independent of number of layers Linear polarization correctly predicts trends 36

38 Acknowledgements Inam Jawed, NCHRP-IDEA Michael Sprinkel, VTRC Nils Olsson, Hillsborough County Prof. A. Sagues, USF National Science Foundation Graduate Students Mike Stokes, Greg Deese, Kadir Uslu, Ivan Gualtero Florida DOT Federal Highway Administration Air Logistics, CA Fyfe Company LLC 37