Bronx, NY
Unionport Bridge
Scope/Solutions
During construction of an approach span to a new bascule bridge, New York City Department of Transportation questioned the finishing procedures and long-term durability of the concrete bridge deck. Working for the construction team, SGH evaluated the concrete finish and materials to determine if the in-place materials satisfied the project specification requirements.
SGH evaluated the concrete and developed recommendations to enhance the expected durability of the concrete. Highlights of our work include:
- Reviewing the New York City Department of Transportation specifications for high‑performance concrete, which was required for the new deck
- Using ground penetrating radar to identify locations where core sampling would not impact the embedded reinforcing steel
- Measuring surface crack widths and depths at extracted core samples
- Performing testing in our laboratory to evaluate the concrete’s chloride ion permeability per ASTM C1202
- Recommending the contractor apply a methyl methacrylate sealer to the approach span to reduce permeability
- Collaborating with the construction team to coordinate the bridge deck tining with the sealer installation
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Project Summary
2024
Completion Date
Solutions
Evaluation
Services
Structures | Applied Science & Research
Markets
Infrastructure & Transportation
Client(s)
Unionport Constructors, JV
Specialized Capabilities
Repair & Strengthening | Materials Science
Key team members
Nathaniel Smith
Managing Principal, Structural Engineering, New York
Additional Projects
Northeast
Tuskegee Airmen (formerly 100th Street) Bus Depot
The contractor attempted to repair the 280,000 sq ft of elevated decks and ramps, but subsequent cracking, including some through the previous repairs, raised concern about the service life of the depot. SGH investigated the cause of cracking in the concrete slabs.
Northeast
MBTA Sullivan Square Station
SGH performed a structural safety evaluation, designed canopy and platform repairs, directed a multidisciplinary team in the design of station brightening options, and performed construction phase services during an on-call contract.