Inspect concrete filled-grid steel decks at joints and bridge ends for which condition?

• A. Expansion due to corrosion
• B. Cracking of the deck
• C. Rust staining around fasteners
• D. Spalling at the deck surface

Answer: (A)

Expansion due to corrosion is the condition inspectors look for at joints and bridge ends because rust forming inside the steel grid and embedded reinforcement expands as it corrodes. That expansion occurs within the confined concrete of a concrete-filled grid deck, pushing against the surrounding material and causing cracking, spalling, and movement at joints and deck ends. This specific deterioration signal—pressure from rust—directly indicates active degradation that can compromise deck performance, more so than surface signs like staining or isolated cracking that may have other causes. While cracking, rust staining, or surface spalling can occur for various reasons, expansion from corrosion at these locations is the clearest sign of harmful internal deterioration that requires attention.