On the middle-level parking deck, the owner noticed potholes, unevenness, and cracking. The deck plan shows where concrete delamination or spalling was discovered: 60% in Slab Area 1 and 10% to 20% in Slab Area 2. The deterioration pattern suggests vehicles tracked deicing salts into the garage, which corroded the embedded reinforcement where drivers most often parked.
Several types of concrete deterioration were observed: delamination and spalling of the driving surface and bases of columns in areas adjacent to steel reinforcement, and cracking.
Based on the significant amount of top surface deterioration in Slab Area 1, the reinforcing bars were conservatively judged to be debonded from the concrete and therefore structurally ineffective. The concrete columns had only small localized deterioration, and were determined to be structurally sound.