1. Are We Abandoning Bridges with Remaining Life?
Dave Whitmore
Vector Corrosion Technologies

2. Corrosion Ravaged Column
Repaired and still in service
Corrosion Ravaged Column

3. Corrosion Ravaged Columns
Not repaired. Demolished and replaced
Corrosion Ravaged Columns
Chicago, Illinois

4. Abandoning Structures: Outline
How do we Decide When to Replace?
What are the Criteria? Who Decides?
Is the Structure Really Finished?
Is it Practically Preservable
What Information do we Need to Make This Decision?
Are we Collecting the Right Information?
Case Studies

5. Compliments of Computer History Museum

6. How Do We Decide to Replace a Bridge?
Functional Reasons
# Lanes, Width, Shoulders, Etc.
Not Entirely Functional Reasons
Policy (May include Age and Type of Structure)
Guidelines / Criteria (ie. % Delaminated Area, Rehab Cost vs Replacement Cost)
Bridge Rating (less than ??) / Appearance / Other
These Methods Assume
Correlation to Capacity, Safety and Service Life
Deterioration will Continue Unabated

7. Bridge Deck Deterioration
Bridge Replaced

8. Substructure with Deterioration. Long Term Rehabilitation completed.

10. Coniston Creek Bridge, 1975. Concern about capacity
Coniston Creek Bridge, Concern about capacity. Load testing confirmed it had ample capacity.

11. Perley Bridge. 34 spans between Ontario and Quebec
Perley Bridge. 34 spans between Ontario and Quebec. Bridge was posted 40 ton max load. Posting removed in Bridge replaced in 2000 due to narrow width and corrosion.

12. Manitou Bridge (to Toronto Island). Concrete encased steel beams
Manitou Bridge (to Toronto Island). Concrete encased steel beams. Was posted 6.8 ton max load. Posting removed No posting to date.

13. 101 Bridges Bridge inspection in Canada is largely visual
Bridges instrumented and load tested
75% of Bridges had higher load carrying capacity than presumed from analysis

14. St. Adolphe over Red River
Portion of bridge demolished due to failure / slide of one bridge pier. Two beams from one span were load tested to determine actual capacity.

15. Strain gauges installed to monitor during loading.

16. Two girders held almost 500,000 lb mid-span point load!

17. I-480 Omaha
Bridge repaired in 1997.

18. Piers after ECE Treatment and Coating Application
ECE Completed
Bridge remains in service today
Piers after ECE Treatment
and Coating Application

19. I-480 Omaha Environmental / Sustainability Benefit
6,700 yd3 of concrete was maintained in service.
Reduced CO2 emissions by 3,350 tons.
Equivalent to annual emissions of 670 people.

21. Lake Pontchartrain Causeway
Case Study: Hwy 11
Lake Pontchartrain Causeway
Despite the dire warnings in the news video, the US 11 bridge remains in service
Repairs to extend its service life are in progress

22. Lake Pontchartrain Causeway
Case Study: Hwy 11
Lake Pontchartrain Causeway
This bridge is currently being repaired and strengthened (2017 – 2018).
Repairs to address corrosion and extend service life are in progress

23. Presentation Summary How Do We Decide When to Replace a Bridge?
Visual Appearance vs Testing Data
Guidelines / Criteria vs Analysis

25. Thank You ?