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l Superstructure Replacement l Substructure Repair PowerPoint Presentation
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l Superstructure Replacement l Substructure Repair

l Superstructure Replacement l Substructure Repair

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l Superstructure Replacement l Substructure Repair

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  1. 10 9 8 7 6 5 4 3 2 1 Rehabilitation of I-95 Bridges 11 Bridges Along I-95 Corridor l Superstructure Replacement l Substructure Repair

  2. ROLLED BEAMS l Existing deck is 7-1/2” thick l Replacement deck creates overstress in beams l Category E fatigue detail at cover plate ends l Paint is in poor condition and lead based l Replace steel beams

  3. Rehabilitation of I-95 Bridges Bridge Widening l Lombardy/CSX Bridge 12’ Shoulders (8’-8” Widening Each Side) l Robin Hood Rd. Bridge Ramp Extension (14’-8” Widening SBL) l Sherwood Ave. Bridge Ramp Extension (14’-8” Widening SBL)

  4. Rehabilitation of I-95 Bridges Superstructure Replacement l Preconstructed Composite Units (PCU)

  5. PCU’sChosen option uses Pre-Constructed Units assembled in a casting yard, trucked to site and lifted into place by cranes PCU ready in Casting Yard PCU Being Placed during early test day

  6. Construction Sequence

  7. Construction Sequence

  8. Construction SequenceSetup of Maintenance of Traffic Initiating MOT Traffic Shifting Moveable Traffic Barrier Setup Traffic waiting to Shift

  9. Construction SequencePreparation for PCU Cut Deck and Diaphragms and remove Existing Repair Bearing Pads Repaired Pier Cap

  10. Construction Sequence Preparation & Installation Placement of PCU Moving PCU to Pick up Point

  11. Construction Sequence Placing PCU Aligning PCU & then Disconnecting

  12. Rehabilitation of I-95 Bridges l Match-Cast Longitudinal Joint l Cast-in-Place Closure Pour Highly Skew Bridges Lombardy / CSX Robin Hood Hermitage Westwood

  13. Rehabilitation of I-95 Bridges Substructure Repair l Surface Repairs at Abuts. & Piers l Pier Cap Replacement 5 Piers for Lombardy/CSX Bridge l Pier Cap Strengthening Infill Wall between Columns on Piers at Boulevard Bridge

  14. Rehabilitation of I-95 Bridges Substructure Repair l Cathodic Protection Chloride Extraction (ECE) Sealing Concrete Surfaces Pier Caps

  15. SCS’s Role in 11 Bridges Constructed in 1950’s (60 years old) Heavy traffic corridor Full replacement: costly, disruptive

  16. Corrosion Cost Progression Potential Failure Damage Accelerates Critical Point Cost of Maintenance First Visible Damage Internal Damage Poor: Replace Good Fair Preserve Extend Life Condition of Structure

  17. Temporary Piers

  18. Corrosion Damage

  19. Corrosion Damage

  20. Evaluation • How much delam/spall existed at the time? • Chloride presence at various depths? • Future penetration & effects of chlorides? • Active corrosion occurring? How quickly? • Existing and future damage? • Presence and progression of ASR? High risk of prescribing a poor solution without proper diagnosis…

  21. Boulevard - Structure Total Chloride Concentration Histogram

  22. Abutment Wall Line Scan 28 Line Scan 29

  23. GPR – Good Concrete

  24. GPR – Delam. Concrete

  25. Conclusions • Visible concrete damage – significant increase • Developed a concrete damage % for each element • Average recorded cover – low • Majority of potential readings – active corrosion • High chloride readings behind rebars • Near future concrete damage will result • Significant weakening of the structure within five years

  26. Recommendations • Based on a unique methodology, we developed recommendations for repair / replace / • life extension • Concrete repair on all bridges • ECE to lower the chloride concentration on • certain bridges • Sacrificial CP on the rest of the bridges • Sprayed Zinc – widely used, easy to apply